<SUBMISSION>
<ACCESSION-NUMBER>0000950123-04-014407
<TYPE>SC TO-I
<PUBLIC-DOCUMENT-COUNT>9
<FILING-DATE>20041203
<DATE-OF-FILING-DATE-CHANGE>20041203
<SUBJECT-COMPANY>
<COMPANY-DATA>
<CONFORMED-NAME>REGENERON PHARMACEUTICALS INC
<CIK>0000872589
<ASSIGNED-SIC>2834
<IRS-NUMBER>133444607
<STATE-OF-INCORPORATION>NY
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC TO-I
<ACT>34
<FILE-NUMBER>005-41938
<FILM-NUMBER>041184687
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>777 OLD SAW MILL RIVER RD
<CITY>TARRYTOWN
<STATE>NY
<ZIP>10591-6707
<PHONE>9143477000
</BUSINESS-ADDRESS>
</SUBJECT-COMPANY>
<FILED-BY>
<COMPANY-DATA>
<CONFORMED-NAME>REGENERON PHARMACEUTICALS INC
<CIK>0000872589
<ASSIGNED-SIC>2834
<IRS-NUMBER>133444607
<STATE-OF-INCORPORATION>NY
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC TO-I
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>777 OLD SAW MILL RIVER RD
<CITY>TARRYTOWN
<STATE>NY
<ZIP>10591-6707
<PHONE>9143477000
</BUSINESS-ADDRESS>
</FILED-BY>
<DOCUMENT>
<TYPE>SC TO-I
<SEQUENCE>1
<FILENAME>y69289sctovi.htm
<DESCRIPTION>ISSUER TENDER OFFER
<TEXT>
<HTML>
<HEAD>
<TITLE>ISSUER TENDER OFFER</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="center" style="font-size: 14pt"><B>SECURITIES AND EXCHANGE COMMISSION</B>

<DIV align="center" style="font-size: 12pt"><B>WASHINGTON, D.C. 20549</B>
</DIV>


<P align="center" style="font-size: 12pt"><B>SCHEDULE TO<BR>
TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)<BR>
OF THE SECURITIES EXCHANGE ACT OF 1934<BR>
(Amendment No.)</B>


<P align="center" style="font-size: 24pt"><B>Regeneron Pharmaceuticals, Inc.</B>

<DIV align="center" style="font-size: 10pt">(Name of Subject Company (Issuer))</DIV>


<P align="center" style="font-size: 24pt"><B>Regeneron Pharmaceuticals, Inc.</B>

<DIV align="center" style="font-size: 10pt">(Name of Filing Person (Offeror))</DIV>



<P align="center" style="font-size: 10pt"><B>Options under the 1990 Long-Term Incentive Plan<BR>
and 2000 Long-Term Incentive Plan<BR>
to Purchase Common Stock, Par Value $.001 Per Share,<BR>
Having an Exercise Price Per Share of $18.00 or More</B><BR>
(Title of Class of Securities)



<P align="center" style="font-size: 10pt"><B>00075886F1</B><BR>
(CUSIP Number of Class of Securities)<BR>
(Underlying Common Stock)



<P align="center" style="font-size: 10pt"><B>Stuart Kolinski, Esq.<BR>
Vice President, General Counsel and Secretary<BR>
Regeneron Pharmaceuticals, Inc.<BR>
777 Old Saw Mill River Road<BR>
Tarrytown, New York 10591<BR>
(914)&nbsp;347-7000</B><BR>
(Name, Address and Telephone Number of Person Authorized to<BR>
Receive Notices and Communications on Behalf of Filing Person)



<P align="center" style="font-size: 10pt"><B><I>Copy to:</I></B>



<P align="center" style="font-size: 10pt"><B>Kent A. Coit, Esq.<BR>
Skadden, Arps, Slate, Meagher &#038; Flom LLP<BR>
One Beacon Street<BR>
Boston, MA 02108<BR>
Telephone: (617)&nbsp;573-4800<BR>
Facsimile: (617)&nbsp;573-4822</B>






<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<P align="center" style="font-size: 10pt"><B>CALCULATION OF FILING FEE</B>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="61%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="16%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="17%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Transaction Valuation*</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Amount of Filing Fee**</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">$13,162,587.66</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">1,667.70</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="96%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Calculated solely for purposes of determining the filing fee. This
amount assumes that options to purchase 4,847,581 shares of common stock
of Regeneron Pharmaceuticals, Inc. having an approximate aggregate value
of $13,162,587.66 will be exchanged pursuant to this Offer. The
aggregate value of such options was calculated based on the Black-Scholes
option pricing model, as of November&nbsp;3, 2004.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">**
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">The amount of the filing fee, calculated in accordance with Rule&nbsp;0-11 of
the Securities Exchange Act of 1934, as amended, equals $126.70 for each
$1,000,000 of the aggregate value of this transaction.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><FONT face="Wingdings">&#111;</FONT>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Check the box if any part of the fee is offset as provided by Rule&nbsp;0-11(a)(2) and
identify the filing with which the offsetting fee was previously paid. Identify the previous filing
by registration statement number, or the Form or Schedule and the date of its filing.</TD>
</TR>

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</TABLE>
</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="58%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="37%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Amount Previously Paid: Not applicable.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Filing Party: Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Form or Registration No.: Not applicable.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Date Filed: Not applicable.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="96%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><FONT face="Wingdings">&#111;</FONT>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Check the box if the filing relates solely to preliminary communications made before the
commencement of a tender offer.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">Check the appropriate boxes below to designate any transactions to which the statement relates:



<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT face="Wingdings">&#111;</FONT> third-party tender offer subject to Rule&nbsp;14d-1.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT face="Wingdings">&#120;</FONT> issuer tender offer subject to Rule&nbsp;13e-4.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT face="Wingdings">&#111;</FONT> going-private transaction subject to Rule&nbsp;13e-3.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT face="Wingdings">&#111;</FONT> amendment to Schedule&nbsp;13D under Rule&nbsp;13d-2.</TD>
</TR>

</TABLE>


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">Check the following box if the filing is a final amendment reporting the
results of the tender offer: <FONT face="Wingdings">&#111;</FONT>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>


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<DIV style="font-family: 'Times New Roman',Times,serif">


<!-- TOC -->
<A name="toc"><DIV align="CENTER" style="page-break-before:always"><U><B>TABLE OF CONTENTS</B></U></DIV></A>

<P><CENTER>
<TABLE border="0" width="90%" cellpadding="0" cellspacing="0">
<TR>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="76%"></TD>
</TR>
<TR><TD></TD><TD colspan="8"><A HREF="#000">Item&nbsp;1. Summary Term Sheet</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#001">Item&nbsp;2. Subject Company Information</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#002">Item&nbsp;3. Identity and Background of Filing Person</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#003">Item&nbsp;4. Terms of the Transaction</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#004">Item&nbsp;5. Past Contacts, Transactions, Negotiations and Agreements</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#005">Item&nbsp;6. Purposes of the Transaction and Plans or Proposals</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#006">Item&nbsp;7. Source and Amount of Funds or Other Consideration</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#007">Item&nbsp;8. Interest in Securities of the Subject Company</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#008">Item&nbsp;9. Persons/Assets, Retained, Employed, Compensated or Used</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#009">Item&nbsp;10. Financial Statements</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#010">Item&nbsp;11. Additional Information</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#011">Item&nbsp;12. Exhibits</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#012">Item&nbsp;13. Information Required by Schedule&nbsp;13E-3</A></TD></TR>
<TR><TD colspan="9"><A HREF="#013">SIGNATURE</A></TD></TR>
<TR><TD colspan="9"><A HREF="#014">INDEX TO EXHIBITS</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99waw1wi.htm">EX-99.A.1.I OFFER TO EXCHANGE</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99waw1wii.htm">EX-99.A.1.II FORM OF ELECTION FORM</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99waw1wiii.htm">EX-99.A.1.III FORM OF NOTICE OF WITHDRAWAL</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99waw1wiv.htm">EX-99.A.1.IV FORM OF ACCEPTANCE LETTER</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99waw1wv.htm">EX-99.A.1.V FORM OF COMMUNICATION</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99wdw7.htm">EX-99.D.7 FORM OF REPLACEMENT OPTION AGREEMENT AND NOTICE OF GRANT OF REPLACEMENT OPTIONS</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99wdw8.htm">EX-99.D.8 FORM OF REPLACMENT OPTION AGREEMENT AND NOTICE OF GRANT OF REPLACEMENT OPTIONS</A></TD></TR>
<TR><TD colspan="9"><A HREF="y69289exv99wdw9.htm">EX-99.D.9 FORM OF REPLACEMENT OPTION AGREEMENT AND NOTICE OF GRANT OF REPLACEMENT OPTIONS</A></TD></TR>
</TABLE>
</CENTER>
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<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>


<!-- link2 "Item&nbsp;1. Summary Term Sheet" -->
<DIV align="left"><A NAME="000"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;1. Summary Term Sheet.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth on the cover page and under &#147;Summary Term Sheet
- Questions and Answers&#148; in the Offer to Exchange dated December&nbsp;3, 2004 and
attached as exhibit (a)(1) hereto (the &#147;Offer to Exchange&#148;) is incorporated
herein by reference.

<!-- link2 "Item&nbsp;2. Subject Company Information" -->
<DIV align="left"><A NAME="001"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;2. Subject Company Information.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Name and Address.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The name of the issuer is Regeneron Pharmaceuticals, Inc., a New York
corporation (the &#147;Company&#148;). The Company&#146;s principal executive offices are
located at 777 Old Saw Mill River Road, Tarrytown, New York 10591 and its
telephone number is (914)&nbsp;347-7000.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Securities.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Schedule&nbsp;TO relates to an offer by the Company to all eligible
employees to exchange such employees&#146; options outstanding under the Company&#146;s
1990 Long-Term Incentive Plan, as amended (the &#147;1990 Plan&#148;) and 2000 Long-Term
Incentive Plan, as amended (the &#147;2000 Plan,&#148; and together with the 1990 Plan,
the &#147;Incentive Plans&#148;) to purchase shares of the Company&#146;s common stock, par
value $.001 per share (the &#147;Common Stock&#148;), having an exercise price of $18.00
or more for replacement options (the &#147;Replacement Options&#148;) to purchase shares
of Common Stock to be granted under the 2000 Plan, upon the terms and subject
to the conditions described in the Offer to Exchange and the related Election
Form (the Offer to Exchange and the Election Form, as they may be amended or
supplemented from time to time, are together referred to as the &#147;Offer&#148;) and
subject to the 2000 Plan and applicable option agreement. The information set
forth in the Offer to Exchange under &#147;Summary Term Sheet - Questions and
Answers,&#148; Section&nbsp;1 - &#147;Eligible Options and Optionholders; Number of
Replacement Options; Expiration Date,&#148; Section&nbsp;2 &#150; &#147;Purpose and Background of
the Offer,&#148; Section&nbsp;5 - &#147;Acceptance of Options for Exchange and Grant of
Replacement Options,&#148; Section&nbsp;6 - &#147;Conditions of the Offer&#148; and Section&nbsp;8 -
&#147;Source and Amount of Consideration; Terms of Replacement Options&#148; is
incorporated herein by reference.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Trading Market and Price.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;7 -
&#147;Price Range of Common Stock Underlying Options&#148; is incorporated herein by
reference.

<!-- link2 "Item&nbsp;3. Identity and Background of Filing Person" -->
<DIV align="left"><A NAME="002"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;3. Identity and Background of Filing Person.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Name and Address.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The
information set forth under Item&nbsp;2 - Name and Address above, and in
Schedule&nbsp;A to the Offer to Exchange, is incorporated herein by reference.

<!-- link2 "Item&nbsp;4. Terms of the Transaction" -->
<DIV align="left"><A NAME="003"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;4. Terms of the Transaction.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Material Terms.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under &#147;Summary Term
Sheet - Questions and Answers,&#148; Section&nbsp;1 - &#147;Eligible Options and
Optionholders; Number of Replacement Options; Expiration Date,&#148; Section&nbsp;3 -
&#147;Procedures for Tendering Options for Exchange,&#148;
Section&nbsp;4 - &#147;Withdrawal
Rights,&#148; Section&nbsp;5 - &#147;Acceptance of Options for Exchange and Grant of
Replacement Options,&#148; Section&nbsp;6 - &#147;Conditions of the Offer,&#148; Section&nbsp;8 -
&#147;Source and Amount of Consideration; Terms of Replacement Options,&#148; Section&nbsp;11
- &#147;Status of Options Tendered in the Offer; Accounting Consequences of the
Offer,&#148; Section&nbsp;12 - &#147;Legal Matters; Regulatory Approvals,&#148; Section&nbsp;13 -
&#147;Certain Federal Income Tax Consequences&#148; and
Section&nbsp;14 - &#147;Extension of Offer;
Termination; Amendment&#148; is incorporated herein by reference.


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Purchases.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;1 -
&#147;Eligible Options and Optionholders; Number of Replacement Options; Expiration
Date&#148; and Section&nbsp;10 - &#147;Interests of Directors and Officers; Transactions and
Arrangements&#148; is incorporated herein by reference.

<!-- link2 "Item&nbsp;5. Past Contacts, Transactions, Negotiations and Agreements" -->
<DIV align="left"><A NAME="004"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;5. Past Contacts, Transactions, Negotiations and Agreements.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Agreements Involving the Subject Company&#146;s Securities.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;8 -
&#147;Source and Amount of Consideration; Terms of Replacement Options,&#148; Section&nbsp;10
- &#147;Interests of Directors and Officers; Transactions and Arrangements&#148; and
under Section&nbsp;9 - &#147;Information Concerning Regeneron Pharmaceuticals, Inc.&#148; is
incorporated herein by reference.

<!-- link2 "Item&nbsp;6. Purposes of the Transaction and Plans or Proposals" -->
<DIV align="left"><A NAME="005"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;6. Purposes of the Transaction and Plans or Proposals.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Purposes.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;2 -
&#147;Purpose and Background of the Offer &#147; is incorporated herein by reference.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Use of Securities Acquired.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;5 -
&#147;Acceptance of Options for Exchange and Grant of Replacement Options&#148; and
Section&nbsp;11 - &#147;Status of Options Tendered in the Offer; Accounting Consequences
of the Offer&#148; is incorporated herein by reference.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Plans.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;2 -
&#147;Purpose and Background of the Offer&#148; is incorporated herein by reference.

<!-- link2 "Item&nbsp;7. Source and Amount of Funds or Other Consideration" -->
<DIV align="left"><A NAME="006"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;7. Source and Amount of Funds or Other Consideration.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Source of Funds.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;8 -
&#147;Source and Amount of Consideration; Terms of Replacement Options&#148; and Section
15 - &#147;Fees and Expenses&#148; is incorporated herein by reference.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Conditions.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Borrowed Funds.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

<!-- link2 "Item&nbsp;8. Interest in Securities of the Subject Company" -->
<DIV align="left"><A NAME="007"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;8. Interest in Securities of the Subject Company.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Securities Ownership.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;10 -
&#147;Interests of Directors and Officers; Transactions and Arrangements&#148; and
Section&nbsp;9 - &#147;Information Concerning Regeneron Pharmaceuticals, Inc.&#148; is
incorporated herein by reference.


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Securities Transactions.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;10 -
&#147;Interests of Directors and Officers; Transactions and Arrangements&#148; is
incorporated herein by reference.

<!-- link2 "Item&nbsp;9. Persons/Assets, Retained, Employed, Compensated or Used" -->
<DIV align="left"><A NAME="008"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;9. Persons/Assets, Retained, Employed, Compensated or Used.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Solicitations or Recommendations.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

<!-- link2 "Item&nbsp;10. Financial Statements" -->
<DIV align="left"><A NAME="009"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;10. Financial Statements.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Financial Information.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;9 -
&#147;Information Concerning Regeneron Pharmaceuticals, Inc. &#150; Summary Financial
Information&#148; is incorporated herein by reference. The financial information
included in Part&nbsp;I of our Quarterly Report on Form 10-Q for the fiscal quarter
ended September&nbsp;30, 2004 filed with the Securities and Exchange Commission on
November&nbsp;8, 2004, and the financial information included in Item&nbsp;8 of our
Annual Report on Form 10-K/A for the fiscal year ending December&nbsp;31, 2003 filed
with the Securities and Exchange Commission on March&nbsp;19, 2004, is incorporated
herein by reference.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Pro Forma Information.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

<!-- link2 "Item&nbsp;11. Additional Information" -->
<DIV align="left"><A NAME="010"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;11. Additional Information.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Agreements, Regulatory Requirements and Legal Proceedings.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in the Offer to Exchange under Section&nbsp;10 -
&#147;Interests of Directors and Officers; Transactions and Arrangements&#148; and
Section&nbsp;12 - &#147;Legal Matters; Regulatory Approvals&#148; is incorporated herein by
reference.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Other Material Information.</U>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

<!-- link2 "Item&nbsp;12. Exhibits" -->
<DIV align="left"><A NAME="011"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;12. Exhibits.</B>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(i)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Offer to Exchange dated December&nbsp;3, 2004.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(ii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Election Form.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(iii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Notice of Withdrawal.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(iv)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Acceptance Letter.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(v)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of communication to Regeneron Pharmaceuticals, Inc.
optionholders confirming receipt of Election Form or Notice of Withdrawal.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(vi)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Quarterly Report on Form&nbsp;10-Q for
its fiscal quarter ended September&nbsp;30, 2004, filed with the Securities and
Exchange Commission on November&nbsp;8, 2004 and incorporated herein by
reference.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(vii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Annual Report on Form&nbsp;10-K/A for
the fiscal year ending December&nbsp;31, 2003 filed with the Securities and
Exchange Commission on March&nbsp;19, 2004 and incorporated herein by
reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(viii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">E-mail communication to Regeneron Pharmaceuticals, Inc. employees
dated November&nbsp;17, 2004 filed as Exhibit&nbsp;99.2 to the Company&#146;s Schedule
TO-C filed with the Securities and Exchange Commission on November&nbsp;17,
2004 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>


<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(2)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(3)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(4)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(5)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(b)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(1)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. 1990 Long-Term Incentive Plan, as
amended, filed as Exhibit&nbsp;10.12 to Amendment No.&nbsp;4 to the Company&#146;s
Registration Statement on Form&nbsp;S-1, filed with the Securities and Exchange
Commission on April&nbsp;2, 1991 (Registration Statement No.&nbsp;033-39043) and
incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(2)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. 2000 Long-Term Incentive Plan, filed as
Exhibit&nbsp;10.6 to the Form&nbsp;10-K for Regeneron Pharmaceuticals, Inc. for the
fiscal year ended December&nbsp;31, 2001, filed with the Securities and
Exchange Commission on March&nbsp;22, 2002 and incorporated herein by
reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(3)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;1 to Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, effective as of June&nbsp;14, 2002, filed as Exhibit&nbsp;10.6.1 to
the Form&nbsp;10-K for Regeneron Pharmaceuticals, Inc. for the fiscal year
ended December&nbsp;31, 2002, filed with the Securities and Exchange Commission
on March&nbsp;31, 2003 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(4)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;2 to Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, effective as of December&nbsp;20, 2002, filed as Exhibit&nbsp;10.6.2
to the Form&nbsp;10-K for Regeneron Pharmaceuticals, Inc. for the fiscal year
ended December&nbsp;31, 2002, filed with the Securities and Exchange Commission
on March&nbsp;31, 2003 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(5)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;3 to Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, effective as of June&nbsp;14, 2004, filed as Exhibit&nbsp;10.6.3 to
the Form&nbsp;10-Q for Regeneron Pharmaceuticals, Inc. for the quarterly period
ended June&nbsp;30, 2004, filed with the Securities and Exchange Commission on
August&nbsp;5, 2004 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(6)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;4 to the Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, included as Annex A to the Company&#146;s definitive proxy
statement on Schedule&nbsp;14A filed with the Securities and Exchange
Commission on November&nbsp;29, 2004 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(7)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Replacement Option Agreement and Notice of Grant of Replacement
Options for employees of Regeneron Pharmaceuticals, Inc. other than vice
presidents.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(8)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Replacement Option Agreement and Notice of Grant of Replacement
Options for vice presidents of Regeneron Pharmaceuticals, Inc.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(9)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Replacement Option Agreement and Notice of Grant of Replacement
Options for senior vice presidents and executive vice presidents of
Regeneron Pharmaceuticals, Inc.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(10)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Registration Statements relating to
Securities to be offered to employees pursuant to employee benefit plans
on Form&nbsp;S-8 and Form&nbsp;S-8 POS, filed with the Securities and Exchange
Commission on August&nbsp;19, 1997 (File No.&nbsp;333-33891), June&nbsp;15, 1999 (File
No.&nbsp;333-80663), May&nbsp;17, 2001 (File No.&nbsp;333-61132), July&nbsp;30, 2002 (File No.
333-80663, July&nbsp;30, 2002 (File No.&nbsp;333-97375) and September&nbsp;24, 2004 (File
No.&nbsp;333-119257) and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(11)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Registration Statement on Form&nbsp;8-A
filed with the Securities and Exchange Commission on February&nbsp;20, 1991 as
amended by the Registration Statement on Form&nbsp;8-A/A, filed with the
Securities and Exchange Commission on March&nbsp;27, 1991 and incorporated
herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(12)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Registration Statement on Form&nbsp;8-A,
filed with the Securities and Exchange Commission on October&nbsp;15, 1996 and
incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(13)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Rights Agreement, dated as of September&nbsp;20, 1996, between Regeneron
Pharmaceuticals, Inc. and Chase Mellon Shareholder Services LLC, as Rights
Agent, including the form of Rights Certificate as Exhibit&nbsp;B thereto,
filed as Exhibit&nbsp;1 to Regeneron Pharmaceuticals, Inc. Registration
Statement on Form&nbsp;8-A, filed with the Securities and Exchange Commission
on October&nbsp;15, 1996 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(g)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(h)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Not applicable.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<!-- link2 "Item&nbsp;13. Information Required by Schedule&nbsp;13E-3" -->
<DIV align="left"><A NAME="012"></A></DIV>

<P align="left" style="font-size: 10pt"><B>Item&nbsp;13. Information Required by Schedule&nbsp;13E-3.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">
<!-- link1 "SIGNATURE" -->
<DIV align="left"><A NAME="013"></A></DIV>

<P align="center" style="font-size: 10pt"><B>SIGNATURE</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this Schedule&nbsp;TO is true, complete and
correct.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="55%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="40%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">REGENERON PHARMACEUTICALS, INC.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By: /s/ Stuart Kolinski<BR>
<HR align="left" size="1" noshade width="80%"></TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name: Stuart Kolinski</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title: Vice President and General Counsel</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">Date: December&nbsp;3, 2004





<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<!-- link1 "INDEX TO EXHIBITS" -->
<DIV align="left"><A NAME="014"></A></DIV>

<P align="center" style="font-size: 10pt">INDEX TO EXHIBITS


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>EXHIBIT</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>&nbsp;</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>NUMBER</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>DESCRIPTION OF EXHIBIT</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(i)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Offer to Exchange dated December&nbsp;3, 2004.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(ii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Election Form.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(iii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Notice of Withdrawal.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(iv)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Acceptance Letter.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(v)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of communication to Regeneron Pharmaceuticals, Inc.
optionholders confirming receipt of Election Form or Notice of Withdrawal.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(vi)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Quarterly Report on Form&nbsp;10-Q for
its fiscal quarter ended September&nbsp;30, 2004, filed with the Securities and
Exchange Commission on November&nbsp;8, 2004 and incorporated herein by
reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(vii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Annual Report on Form&nbsp;10-K/A for
the fiscal year ending December&nbsp;31, 2003 filed with the Securities and
Exchange Commission on March&nbsp;19, 2004 and incorporated herein by
reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(a)(1)(viii)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">E-mail communication to Regeneron Pharmaceuticals, Inc. employees
dated November&nbsp;17, 2004 filed as Exhibit&nbsp;99.2 to the Company&#146;s Schedule
TO-C filed with the Securities and Exchange Commission on November&nbsp;17,
2004 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>


<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(1)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. 1990 Long-Term Incentive Plan, as
amended, filed as Exhibit&nbsp;10.12 to Amendment No.&nbsp;4 to the Company&#146;s
Registration Statement on Form&nbsp;S-1, filed with the Securities and Exchange
Commission on April&nbsp;2, 1991 (Registration Statement No.&nbsp;033-39043) and
incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(2)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. 2000 Long-Term Incentive Plan, filed as
Exhibit&nbsp;10.6 to the Form&nbsp;10-K for Regeneron Pharmaceuticals, Inc. for the
fiscal year ended December&nbsp;31, 2001, filed with the Securities and
Exchange Commission on March&nbsp;22, 2002 and incorporated herein by
reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(3)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;1 to Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, effective as of June&nbsp;14, 2002, filed as Exhibit&nbsp;10.6.1 to
the Form&nbsp;10-K for Regeneron Pharmaceuticals, Inc. for the fiscal year
ended December&nbsp;31, 2002, filed with the Securities and Exchange Commission
on March&nbsp;31, 2003 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(4)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;2 to Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, effective as of December&nbsp;20, 2002, filed as Exhibit&nbsp;10.6.2
to the Form&nbsp;10-K for Regeneron Pharmaceuticals, Inc. for the fiscal year
ended December&nbsp;31, 2002, filed with the Securities and Exchange Commission
on March&nbsp;31, 2003 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(5)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;3 to Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, effective as of June&nbsp;14, 2004, filed as Exhibit&nbsp;10.6.3 to
the Form&nbsp;10-Q for Regeneron Pharmaceuticals, Inc. for the quarterly period
ended June&nbsp;30, 2004, filed with the Securities and Exchange Commission on
August&nbsp;5, 2004 and incorporated herein by reference.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>EXHIBIT</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>&nbsp;</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>NUMBER</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>DESCRIPTION OF EXHIBIT</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(6)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amendment No.&nbsp;4 to the Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, included as Annex A to the Company&#146;s definitive proxy
statement on Schedule&nbsp;14A filed with the Securities and Exchange
Commission on November&nbsp;29, 2004 and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(7)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Replacement Option Agreement and Notice of Grant of Replacement
Options for employees of Regeneron Pharmaceuticals, Inc. other than vice
presidents.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(8)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Replacement Option Agreement and Notice of Grant of Replacement
Options for vice presidents of Regeneron Pharmaceuticals, Inc.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(9)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Form of Replacement Option Agreement and Notice of Grant of Replacement
Options for senior vice presidents and executive vice presidents of
Regeneron Pharmaceuticals, Inc.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(10)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Registration Statements relating to
Securities to be offered to employees pursuant to employee benefit plans
on Form&nbsp;S-8 and Form&nbsp;S-8 POS, filed with the Securities and Exchange
Commission on August&nbsp;19, 1997 (File No.&nbsp;333-33891), June&nbsp;15, 1999 (File
No.&nbsp;333-80663), May&nbsp;17, 2001 (File No.&nbsp;333-61132), July&nbsp;30, 2002 (File No.
333-80663, July&nbsp;30, 2002 (File No.&nbsp;333-97375) and September&nbsp;24, 2004 (File
No.&nbsp;333-119257) and incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(11)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Registration Statement on Form&nbsp;8-A
filed with the Securities and Exchange Commission on February&nbsp;20, 1991 as
amended by the Registration Statement on Form&nbsp;8-A/A, filed with the
Securities and Exchange Commission on March&nbsp;27, 1991 and incorporated
herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(12)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc. Registration Statement on Form&nbsp;8-A,
filed with the Securities and Exchange Commission on October&nbsp;15, 1996 and
incorporated herein by reference.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(d)(13)
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Rights Agreement, dated as of September&nbsp;20, 1996, between Regeneron
Pharmaceuticals, Inc. and Chase Mellon Shareholder Services LLC, as Rights
Agent, including the form of Rights Certificate as Exhibit&nbsp;B thereto,
filed as Exhibit&nbsp;1 to Regeneron Pharmaceuticals, Inc. Registration
Statement on Form&nbsp;8-A, filed with the Securities and Exchange Commission
on October&nbsp;15, 1996 and incorporated herein by reference.</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>




<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A.1.I
<SEQUENCE>2
<FILENAME>y69289exv99waw1wi.htm
<DESCRIPTION>EX-99.A.1.I OFFER TO EXCHANGE
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.A.1.I</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="right" style="font-size: 10pt">Exhibit (a)(1)(i)



<P align="center" style="font-size: 10pt"><B>REGENERON PHARMACEUTICALS, INC.</B>



<P align="center" style="font-size: 10pt"><B>OFFER TO EXCHANGE<BR>
OUTSTANDING OPTIONS TO PURCHASE SHARES<BR>
OF COMMON STOCK OF REGENERON PHARMACEUTICALS, INC.<BR>
GRANTED UNDER THE REGENERON PHARMACEUTICALS, INC. 1990<BR>
LONG-TERM INCENTIVE PLAN AND 2000 LONG-TERM INCENTIVE PLAN<BR>
HAVING AN EXERCISE PRICE PER SHARE OF $18.00 OR MORE<BR>
FOR REPLACEMENT OPTIONS TO BE GRANTED UNDER THE 2000<BR>
LONG-TERM INCENTIVE PLAN.</B>



<P align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="30%">



<P align="center" style="font-size: 10pt"><B>THE OFFER AND WITHDRAWAL RIGHTS EXPIRE<BR>
AT 6:00 P.M., EASTERN TIME, ON JANUARY 5, 2005,<BR>
UNLESS THE OFFER IS EXTENDED BY REGENERON<BR>
PHARMACEUTICALS, INC.</B>

<P align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="30%">


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Regeneron Pharmaceuticals, Inc., which we refer to in this Offer to
Exchange as &#147;we,&#148; &#147;us,&#148; the &#147;Company&#148; or &#147;Regeneron,&#148; is offering eligible
employees a one-time opportunity to exchange (sometimes referred to as
&#147;tender&#148;) some or all of such employees&#146; outstanding stock options to purchase
shares of the Company&#146;s common stock, par value $0.001 per share (the &#147;Common
Stock&#148;) granted under the Regeneron Pharmaceuticals, Inc. 2000 Long-Term
Incentive Plan, as amended (the &#147;2000 Plan&#148;) and the 1990 Long-Term Incentive
Plan, as amended (the &#147;1990 Plan,&#148; and, together with the 2000 Plan, the &#147;Stock
Incentive Plans&#148;) that have an exercise price per share of $18.00 or more, for
replacement options that will be granted under the 2000 Plan (the &#147;Option
Exchange Program&#148;). We are making the offer upon the terms and subject to the
conditions set forth in this Offer to Exchange and in the related accompanying
Election Form (which together, as they may be amended or supplemented from time
to time, constitute the &#147;Offer&#148;).


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer is being made to Company regular employees who, as of December
3, 2004, the date the Offer commenced, are actively employed by us and work an
average of at least 20 hours per week, other than our non-executive employee
director and our president and chief executive officer. The Offer is not being
made to non-employee directors, consultants, former employees, and retirees.
To remain eligible to tender eligible options for exchange and cancellation,
and receive replacement options, pursuant to the Offer, you must continue to be
such a regular employee on the date the Offer expires and on the date the
replacement options are granted (the date and time the replacement options are
granted being referred to as the &#147;Grant Date&#148;).


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer will expire at 6:00 p.m., Eastern Time, on January&nbsp;5, 2005,
unless we extend the Offer (such date as so extended, the &#147;Expiration Date&#148;).
The Grant Date will be on or as of the date we accept eligible options tendered
for exchange in the Offer, which we expect will be on, and in any event will be
promptly after, the Expiration Date.


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">See Section&nbsp;1 &#150; &#147;Eligible Options and Optionholders; Number of Replacement
Options; Expiration Date,&#148; Section&nbsp;5 &#150; &#147;Acceptance of Options for Exchange and
Grant of Replacement Options&#148; and Section&nbsp;14 &#150; &#147;Extension of Offer;
Termination; Amendment.&#148;


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you validly tender options for exchange and cancellation, and such
options are accepted and cancelled, pursuant to the Offer, the number of
replacement options you will receive will depend on the exercise price per
share of the options you tendered, as follows:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>For options with an exercise price per share greater than or equal
to $18.00 and less than or equal to $28.00, you will receive
replacement options at an exchange ratio of one (1)&nbsp;replacement option
for every 1.5 tendered options.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>For options with an exercise price per share greater than or equal
to $28.01 and less than or equal to $37.00, you will receive
replacement options at an exchange ratio of one (1)&nbsp;replacement option
for every two (2)&nbsp;tendered options.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>For options with an exercise price per share greater than or equal
to $37.01, you will receive replacement options at an exchange ratio of
one (1)&nbsp;replacement option for every three (3)&nbsp;tendered options.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Replacement option grants will be rounded down to the nearest whole share
on a grant-by-grant basis and, accordingly, replacement options will not be
granted for fractional shares. Each replacement option will have an exercise
price per share equal to the fair market value per share (as determined under
the 2000 Plan) of the Common Stock as of the Grant Date. Replacement options
will be granted pursuant to a replacement option agreement and will be subject
to the 2000 Plan.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The term of the replacement options you receive in exchange for eligible
options tendered and accepted for exchange in the Offer may, and the vesting
schedule of such replacement options will, be different than the term and
vesting schedule of your tendered options. Each replacement option will have a
term equal to the greater of (1)&nbsp;the remaining term of the tendered option it
replaces and (2)&nbsp;six years from the Grant Date.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Each replacement option granted to:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>an employee other than our executive vice president and senior vice
presidents will ordinarily become vested and exercisable in equal
annual installments on the first, second, third and fourth
anniversaries of the Grant Date.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our executive vice president and senior vice presidents will
ordinarily vest with respect to all the shares underlying such option
if <I>both </I>(1)&nbsp;the Company&#146;s products have achieved gross sales of at
least $100&nbsp;million during any consecutive twelve month period (either
directly by the Company or through its licensees) <I>and </I>(2)&nbsp;the specific
senior or executive vice president has remained employed by the Company
for at least three years from the Grant Date.</TD>
</TR>



</TABLE>

<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">


<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">



</TABLE>


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">For all replacement options, the recipient&#146;s vesting and exercise rights will
be contingent on the recipient&#146;s continued employment through the applicable
vesting dates and subject to the provisions of the 2000 Plan and the applicable
option agreement.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As is generally the case with respect to the options eligible to be
tendered for exchange pursuant to the Offer, the option agreements for
replacement options will include provisions whereby the replacement options may
become fully vested in connection with a &#147;Change in Control&#148; of the Company, as
defined in the 2000 Plan. For a detailed description of the terms of the
replacement options, including the 2000 Plan, see Section&nbsp;8 &#150; &#147;Source and
Amount of Consideration; Terms of Replacement Options.&#148;


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may only tender eligible options for all or none of the shares of
Common Stock subject to a particular option grant, which means that if you
decide to tender any outstanding options subject to a particular option grant,
you must tender all of the options subject to that grant that remain
outstanding.



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Consummation of the Offer is subject to shareholder approval by the
requisite vote at a special meeting of shareholders (sometimes referred to
herein as the &#147;Special Meeting of Shareholders&#148;) of an amendment to the 2000
Plan expressly authorizing the Option Exchange Program and the other conditions
described in Section&nbsp;6 &#151; &#147;Conditions of the Offer&#148;. The Offer is not
contingent upon a minimum number of options being tendered. Shares of our
Common Stock are quoted on The Nasdaq National Market, Inc. under the symbol
&#147;REGN.&#148; On December&nbsp;1, 2004, the last reported sale price of our Common Stock
on The Nasdaq National Market was $9.03 per share. <B>We recommend that you
obtain current market quotations for our Common Stock before deciding whether
to tender your options.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>See the section entitled &#147;Risk Factors&#148; beginning on page 13 for a
discussion of risks that you should consider before tendering your eligible
options.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Although our board of directors has approved the Offer, consummation of
the Offer is subject to shareholder approval and the other conditions described
in this Offer to Exchange. Neither we nor our board of directors makes any
recommendation as to whether you should tender, or refrain from tendering, any
or all of your eligible options in the Offer. You must make your own decision
whether to tender your eligible options.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You should direct questions about the Offer or requests for assistance or
for additional copies of the Offer to Exchange or the Election Form to:
Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New
York 10591, Attention: Human Resources Department, Option Exchange, by phone
at (914)&nbsp;345-STOK or to our internal e-mail address:
OptionsExchange@regeneron.com.


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="center" style="font-size: 10pt">IMPORTANT



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you wish to tender some or all of your eligible options for exchange
and cancellation, and receive replacement options pursuant to the Offer, you
must complete and sign the enclosed Election Form in accordance with its
instructions, and either send it by regular or overnight mail to Regeneron
Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591,
Attention: Human Resources Department, Options Exchange, or deliver it by hand
to either Pam Curtis in our Tarrytown, New York location or Lynne Fuierer in
our Rensselaer, New York location. Delivery by e-mail or other electronic
means will not be accepted. The properly completed and duly executed Election
Form must be received as specified above before the Offer expires at 6:00 p.m.,
Eastern Time, on January&nbsp;5, 2005, or if the Offer is extended by us, the
extended expiration date.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We are not making the Offer to, nor will we accept any tender of options
from or on behalf of, optionholders in any jurisdiction in which the Offer or
the acceptance of any tender of options would not be in compliance with the
laws of such jurisdiction. However, we may, at our discretion, take any
actions necessary for us to make the Offer to our optionholders in any such
jurisdiction.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Tendering eligible options for exchange, and receiving replacement
options, pursuant to the Offer does not confer upon you the right to remain an
employee of Regeneron. The terms of your employment with us remain unchanged.
We cannot guarantee or provide you with any assurance that you will not be
subject to involuntary termination or that you will otherwise remain in the
employ of Regeneron until the Grant Date or thereafter. If you voluntarily
terminate your employment with us, or if we terminate your employment for any
reason, before the Grant Date, even if you tendered eligible options for
exchange in the Offer prior to such termination, such tender will not be
accepted and such eligible options will not be exchanged for replacement
options.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>We have not authorized any person to make any recommendation on our behalf
as to whether you should tender or refrain from tendering your options pursuant
to the Offer. You should rely only on the information contained in this
document or documents to which we have expressly referred you. We have not
authorized anyone to give you any information or to make any representation in
connection with the Offer other than the information and representations
contained in this document or in the related Election Form. If anyone makes
any recommendation or representation to you or gives you any information, you
must not rely upon that recommendation, representation or information as having
been authorized by us.</B>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">




<P align="center" style="font-size: 10pt">TABLE OF CONTENTS


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
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<TR valign="bottom">
    <TD width="92%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Page</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Summary Term Sheet &#151; Questions and Answers</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">1</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Risk Factors</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">13</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">The Offer</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">15</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;1. Eligible Options and Optionholders; Number of
Replacement Options; Expiration Date</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">15</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;2. Purpose and Background of the Offer</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">17</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;3. Procedures for Tendering Options for Exchange</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">20</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;4. Withdrawal Rights</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">21</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;5. Acceptance of Options for Exchange and Grant of
Replacement Options</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">22</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;6. Conditions of the Offer</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">23</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;7. Price Range of Common Stock Underlying Options</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">25</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;8. Source and Amount of Consideration; Terms of
Replacement Options</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">26</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;9. Information Concerning Regeneron Pharmaceuticals, Inc.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">32</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;10. Interests of Directors and Officers; Transactions and
Arrangements</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">37</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;11. Status of Options Tendered in the Offer; Accounting
Consequences of the Offer</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">39</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;12. Legal Matters; Regulatory Approvals</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">40</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;13. Certain Federal Income Tax Consequences</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">40</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;14. Extension of Offer; Termination; Amendment</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">41</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;15. Fees and Expenses</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">42</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;16. Forward-Looking Statements</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">42</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;17. Additional Information</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">43</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Section&nbsp;18. Miscellaneous</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">44</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Schedule&nbsp;A &#151; Information Concerning the Directors and Executive Officers of
Regeneron Pharmaceuticals, Inc.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">A-1</TD>
    <TD>&nbsp;</TD>
</TR>

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</TABLE>
</DIV>



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<DIV style="font-family: 'Times New Roman',Times,serif">





<P align="center" style="font-size: 10pt"><B>SUMMARY TERM SHEET &#151; QUESTIONS AND ANSWERS</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following summary term sheet is in question and answer format and is
provided to address some of the questions that you may have about the Offer.
We urge you to read carefully the remainder of this Offer to Exchange and the
accompanying Election Form because the information in this summary is not
complete, and additional important information is contained in the remainder of
this Offer to Exchange and the accompanying Election Form. We have included
references to the relevant sections in the Offer to Exchange where you can find
a more complete description of the topics in this summary.


<P align="left" style="font-size: 10pt"><B>What securities are we offering to exchange?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We are offering eligible employees a one-time opportunity to exchange
outstanding stock options granted under the 2000 Plan or the 1990 Plan having
an exercise price per share of $18.00 or more, properly tendered and accepted
for exchange in accordance with the Offer, for replacement options to be
granted under the 2000 Plan. See Section&nbsp;1 &#150; &#147;Eligible Options and
Optionholders; Number of Replacement Options; Expiration Date.&#148;


<P align="left" style="font-size: 10pt"><B>Who is eligible to participate in the Option Exchange Program?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Regular employees, other than our non-executive employee director and our
president and chief executive officer, who on December&nbsp;3, 2004 and on the Grant
Date are actively employed by us and work an average of at least 20 hours per
week are eligible to participate in the Option Exchange Program and,
accordingly, to tender eligible options for exchange and cancellation, and
receive replacement options, pursuant to the Offer. Employees who meet the
eligibility requirements at the commencement of the Offer but do not satisfy
these requirements on the Grant Date are not eligible to exchange their
eligible options. Our non-employee directors, consultants, former employees,
and retirees are not eligible to participate in the Option Exchange Program.
See Section&nbsp;1 &#150; &#147;Eligible Options and Optionholders; Number of Replacement
Options; Expiration Date &#150; Eligible Options and Optionholders.&#148;


<P align="left" style="font-size: 10pt"><B>Why are we making the Offer?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Our stock incentive program is intended to help align the interests of our
employees with our shareholders by encouraging ownership by employees of
Company stock. The price of our Common Stock has declined sharply since 2000.
As of November&nbsp;3, 2004, approximately 54% of the outstanding options granted
under the Stock Incentive Plans had an exercise price above $18 per share. The
per share exercise prices for the annual stock option grants for employees in
the past four years have been $37.78 (in December&nbsp;2000), $28.01 (in December
2001), $19.43 (in December&nbsp;2002), and $13.00 (in December&nbsp;2003). On November
3, 2004, the date as of which option values and exchange ratios were determined
for purposes of the Option Exchange Program, the closing price per share of our
Common Stock on The Nasdaq National Market was $7.88. On December&nbsp;1, 2004, the
closing price per share of our Common Stock on The Nasdaq National Market was
$9.03. The exercise prices noted above, as


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">compared to current market values for the Common Stock, illustrate that a
substantial number of the outstanding options granted pursuant to the Stock
Incentive Plans are &#147;out of the money&#148; and no longer serve as effective
incentives to retain and motivate employees. In today&#146;s competitive market for
top talent in the pharmaceutical and biotechnology industries, the Compensation
Committee of the board of directors and the board believe that it is important
for the future success of the Company to revitalize the incentive value of our
stock incentive program as part of our overall compensation program to retain,
motivate and reward employees. See Section&nbsp;2 &#150; &#147;Purpose and Background of the
Offer.&#148;


<P align="left" style="font-size: 10pt"><B>Why don&#146;t we simply reprice the current options?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer is intended to revitalize our stock incentive program by
permitting eligible optionholders to voluntarily exchange their &#147;out of the
money&#148; eligible options with exercise prices of $18 or more for replacement
options with an exercise price per share of our Common Stock equal to the fair
market value as of the date of grant of the replacements options (determined in
accordance with the 2000 Plan). However, unlike a mere repricing, the Offer is
intended to provide for an exchange of options based approximately on fair
values of options tendered and replacement options granted, with aggregate
values favorable to shareholders, thereby striking a balance between the
interests of employees and the interests of our shareholders.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;By granting replacement options which will be exercisable for fewer shares
than the existing eligible options tendered for exchange in the Offer, the
Offer is also designed to reduce the number of outstanding options. If 100% of
eligible options were tendered for exchange and accepted, and grants of
replacement options were made, pursuant to the Offer, the number of shares of
Common Stock underlying options outstanding would be reduced by approximately
2,271,216 shares. The actual net reduction in shares of Common Stock
underlying options outstanding will depend on the extent to which eligible
options are tendered for exchange and accepted pursuant to the Offer. The
shares underlying options which are tendered for exchange and accepted pursuant
to Offer will be returned to the 2000 Plan and will be available for future
grants of options or other awards under the 2000 Plan.


<P align="left" style="font-size: 10pt"><B>What are the conditions of the Offer?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Completion of the exchange of options pursuant to the Offer is subject to
a number of conditions. These include, among other things, shareholder
approval of the amendment of the 2000 Plan expressly authorizing the Option
Exchange Program. This and various other conditions are more fully described
in Section&nbsp;6 &#150; &#147;Conditions of the Offer.&#148; The Offer is not conditioned upon a
minimum number of options being tendered.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What happens if the Company&#146;s shareholders do not approve at the Special
Meeting of Shareholders the amendment to the 2000 Plan to expressly authorize
the Option Exchange Program?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer will not be consummated, there will be no exchange of options
under the Option Exchange Program, and the Option Exchange Program and the
Offer will


<P align="center" style="font-size: 10pt">2
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">automatically terminate, if the amendment to the 2000 Plan to expressly
authorize the Option Exchange Program does not receive the requisite
affirmative vote of shareholders at the Special Meeting of Shareholders to be
held on December&nbsp;17, 2004, or any adjournment or postponement thereof. See
Section&nbsp;6 &#150; &#147;Conditions of the Offer.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Are there any eligibility requirements that I must satisfy to tender my options
for exchange and receive the replacement options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yes. To participate in the Option Exchange Program and receive
replacement options, you must hold eligible options as well as meet the
eligibility requirements described in this Offer to Exchange and remain
continuously employed by the Company as a regular actively employed employee
who works an average of at least 20 hours per week through the Grant Date. If
you are no longer actively employed by the Company on the Grant Date for any
reason, you will not be eligible to exchange your options for replacement
options. Participation in the Option Exchange Program does not confer upon you
the right to remain employed by us. See Section&nbsp;1 &#150; &#147;Eligible Options and
Optionholders; Number of Replacement Options; Expiration Date &#150; Eligible
Options and Optionholders.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What if I am out of the office or on authorized leave of absence on the date of
the Offer or on the Grant Date?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Any eligible employee who is not actively at work because of vacation,
short-term leave, or other similar reasons will not be disqualified from
participating in the Option Exchange Program due to this absence. Similarly,
if you properly tender eligible options for exchange in the Offer which are
accepted for exchange and cancellation, and you are on authorized leave on the
Grant Date, then upon the terms and subject to the conditions of the Offer, you
will be entitled to receive replacement options (as long as the other
eligibility requirements are still met) in exchange for such tendered options.
See Section&nbsp;1 &#150; &#147;Eligible Options and Optionholders; Number of Replacement
Options; Expiration Date &#150; Eligible Options and Optionholders.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>If I elect to tender for exchange eligible options, will my elections affect
other components of my compensation?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;No.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>How do I find out how many eligible options I have and what their exercise
prices are?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Election Form enclosed with this Offer to Exchange includes a list of
your eligible options as of December&nbsp;1, 2004. In addition, you can at any time
confirm what options you have, their grant dates (and remaining term), exercise
prices, vesting dates, and other information by going to www.optionslink.com.
Employees who do not have their optionslink password should send an email to
optionslink@etrade.com and request their Regeneron logon information. You may
also call 1-800-838-0908, press 0 to speak to a customer service agent, and ask
for your Regeneron logon information.


<P align="center" style="font-size: 10pt">3
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Must I tender options for exchange in the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;No.&nbsp;Whether or not you tender options for exchange in the Offer is solely
your decision and completely voluntary.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>How many replacement options will I receive in exchange for my tendered options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you meet the eligibility requirements and your options are properly
tendered and accepted for exchange, you will be entitled to receive replacement
options exercisable for a number of shares of our Common Stock based on the
following exchange ratios:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="90%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="77%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="9%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exchange Ratio</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>Exercise Price Range</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>(number of eligible options to be tendered and</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>of Eligible Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>canceled for each replacement option)</B><HR size="1" noshade></TD>
</TR>

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    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px">$18.00 - $28.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1.50</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px">$28.01 - $37.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2.00</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:20px; text-indent:-10px">$37.01 and up</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">3.00</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Replacement option grants will be made in accordance with the foregoing
exchange ratios and will be rounded down to the nearest whole share on a
grant-by-grant basis. Accordingly, replacement options will not be granted for
fractional shares. See Section&nbsp;1 &#150; &#147;Eligible Options and Optionholders; Number
of Replacement Options; Expiration Date &#150; Number of Replacement Options.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>If I choose to tender eligible options for exchange in the Offer, do I have to
tender all of my options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In order to tender an eligible option from a particular option grant, you
must tender all outstanding eligible options under that grant. We are not
accepting partial tenders of particular option grants. For example, if you
hold an option to purchase 1,000 shares of Common Stock at an exercise price of
$19.43 per share, you must tender such option in its entirety; you cannot
tender only part of the option and retain the remainder of the option. On the
other hand, if you have an option to purchase 1,000 shares of Common Stock at
an exercise price of $19.43 per share and an option to purchase 2,000 shares of
Common Stock at an exercise price of $28.01 per share, you may choose to tender
for exchange all (but not less than all) of the outstanding options under
either of the option grants, both of the option grants or neither of the option
grants, provided such options are eligible to be tendered in the Offer.
Similarly, if you have an incentive stock option to purchase 700 shares of
Common Stock at an exercise price of $19.43 and a nonqualified stock option to
purchase 300 shares of Common Stock at $19.43, you may choose to tender for
exchange all (but not less than all) of the outstanding options under either of
the option grants, both of the option grants, or neither of the option grants,
provided such options are eligible to be tendered in the Offer. See Section&nbsp;1
&#150; &#147;Eligible Options and Optionholders; Number of Replacement Options;
Expiration Date &#150; Eligible Options and Optionholders.&#148;


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<P align="left" style="font-size: 10pt"><B>Can I tender for exchange both vested and unvested options?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yes. If you are an eligible optionholder, you can tender any option
granted to you under the Stock Incentive Plans that has not expired by its
terms and that has an exercise price above $18.00 per share. However, if an

outstanding eligible option grant includes both vested and unvested options,
you must tender all of both the vested and unvested options if you tender any
options of such grant.


<P align="left" style="font-size: 10pt"><B>Can I exchange options that I have already fully exercised?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;No.&nbsp;The Offer applies only to outstanding eligible options. An option
grant that has been fully exercised, or any portion of a particular option
grant that has been exercised, is no longer outstanding and thus is not
eligible to be tendered for exchange in the Offer.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Can I exchange the remaining portion of an eligible option grant that I have
already partially exercised?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yes. If you have previously partially exercised an eligible option grant,
you can still tender for exchange the remaining unexercised portion of an
eligible option grant.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What will the terms of my replacement options be?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The replacement options that you will receive will be granted under the
2000 Plan and will be subject to the terms and conditions of the 2000 Plan and
an applicable replacement option agreement, which will be substantially in the
form of exhibit (d)(7), (d)(8) or (d)(9), as applicable, to the Tender Offer
Statement on Schedule&nbsp;TO that we originally filed with the Securities and
Exchange Commission (the &#147;SEC&#148;) on December&nbsp;3, 2004 (as the same may be amended
or supplemented from time to time, the &#147;Schedule&nbsp;TO&#148;).


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The term of the replacement options you receive in exchange for eligible
options tendered and accepted for exchange in the Offer may, and the vesting
schedule of such replacement options will, be different from the term and
vesting schedule of your tendered options. You should carefully review the
description of the replacement options and the terms and conditions of the 2000
Plan in Section&nbsp;8 &#150; &#147;Source and Amount of Consideration; Terms of Replacement
Options &#150; Description of the Material Terms of the 2000 Plan,&#148; before making a
decision to tender your options.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What will the exercise price of the replacement options be?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The per share exercise price of the replacement options will be equal to
the fair market value per share (as determined under the 2000 Plan) of the
Common Stock on the Grant Date. Accordingly, we cannot predict the exercise
price of the replacement options. <B>We recommend that you obtain current market
quotations for our Common Stock before deciding whether to tender your options
for exchange in the Offer. </B>See Section&nbsp;5 &#150; &#147;Acceptance of Options for Exchange
and Grant of Replacement Options&#148; and Section&nbsp;7 &#150; &#147;Price Range of Common Stock
Underlying Options.&#148;


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<P align="left" style="font-size: 10pt"><B>What will be the term of my replacement options?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The term of an option is the maximum length of time during which it may be
exercised. Each replacement option granted in exchange for eligible options
validly tendered and accepted pursuant to the Offer will have a maximum term
equal to the greater of (1)&nbsp;the remaining term of the tendered option it
replaces and (2)&nbsp;six years from the Grant Date. See Section&nbsp;8 &#150; &#147;Source and
Amount of Consideration; Terms of Replacement Options &#150; Terms of Replacement
Options.&#148;


<P align="left" style="font-size: 10pt"><B>When will my replacement options vest?</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The replacement options will vest on a different schedule than your
tendered options. Each replacement option will be completely unvested upon
grant. Each replacement option granted to an employee other than our executive
vice president and senior vice presidents will ordinarily become vested and
exercisable in equal annual installments on each of the first, second, third
and fourth anniversaries of the Grant Date. Each replacement option granted to
our executive vice president and senior vice presidents will ordinarily vest
with respect to all the shares underlying such option if <I>both </I>(i)&nbsp;the Company&#146;s
products have achieved gross sales of at least $100&nbsp;million during any
consecutive twelve month period (either directly by the Company or through its
licensees) <I>and </I>(2)&nbsp;the specific senior or executive vice president has remained
employed by the Company for at least three years from the Grant Date. For all
replacement options, the recipient&#146;s vesting and exercise rights will be
contingent on the recipient&#146;s continued employment through the applicable
vesting dates and subject to the provisions of the 2000 Plan and the applicable
option agreement.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As is generally the case with respect to the options eligible for exchange
pursuant to the Option Exchange Program, the option agreements for replacement
options will include provisions whereby the replacement options may become
fully vested in connection with a &#147;Change in Control&#148; of the Company, as
defined in the 2000 Plan. For a more detailed discussion of the vesting of the
replacement options, please see Section&nbsp;8 &#150; &#147;Source and Amount of
Consideration; Terms of Replacement Options &#150; Terms of Replacement Options.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Will I lose the benefits of any vesting I have under my existing options if I
tender those options in the Offer and they are accepted for exchange and
canceled?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yes. You will lose the benefits of any vesting under options you validly
tender which are accepted and exchanged for replacement options pursuant to the
Offer. The replacement options we grant will vest in accordance with the
schedule described above and in Section&nbsp;8 &#150; &#147;Source and Amount of
Consideration; Terms of Replacement Options &#150; Terms of Replacement Options.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>If my current options are incentive stock options, will my replacement options
be incentive stock options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If options tendered for exchange in the Offer qualified as incentive stock
options under U.S. tax laws, then the replacement options for employees other
than our executive


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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">vice president and senior vice presidents will also be incentive stock
options to the fullest extent permitted under Section&nbsp;422 of the Internal
Revenue Code of 1986, as amended. However, the holding period required in
order for such options to be entitled to the favorable tax treatment available
for incentive stock options (which generally provides that stock acquired
pursuant to such options may not be disposed of within two years from the date
of grant and one year from the date of exercise) will recommence as of the
Grant Date. Replacement options for our executive vice president and senior
vice presidents will not be incentive stock options. If your replacement
options are incentive stock options, pursuant to applicable U.S. federal income
tax law, we may need to limit the number of future incentive stock option
awards you may receive that are scheduled to become vested and exercisable in
the same year(s) as the replacement options. Options that are not eligible for
treatment as incentive stock options may be granted as nonqualified stock
options. See Section&nbsp;8 &#150; &#147;Source and Amount of Consideration; Terms of
Replacement Options &#150; Certain Federal Income Tax Consequences&#148; and Section&nbsp;13 &#150;
&#147;Certain Federal Income Tax Consequences.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Will I have to pay taxes if I exchange my options in the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you exchange your current options for replacement options, we believe
that you will not be required under current law to recognize income for United
States federal income tax purposes at the time of the exchange. We recommend
that you consult with your own tax advisor to determine the tax consequences to
you of the Offer. See Section&nbsp;13 &#150; &#147;Certain Federal Income Tax Consequences.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Will I have any rights or benefits with respect to options I tender in the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;No.&nbsp;Options tendered and accepted for exchange in the Offer will be
cancelled and you will no longer have any rights or benefits under those
options. See Section&nbsp;5 &#150; &#147;Acceptance of Options for Exchange and Grant of
Replacement Options.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>If I tender options in the Offer, will I be able to receive other option grants
before I receive my replacement options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We intend to continue to grant option awards to employees from time to
time as part of our normal compensation program. We expect that many employees
eligible to participate in the Option Exchange Program will receive additional
option grants, in accordance with the Company&#146;s past practice, in December
2004. See Section&nbsp;10 &#150; &#147;Interests of Directors and Officers; Transactions and
Arrangements.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What happens to options that I choose not to tender or that are not accepted
for exchange in the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Nothing. Options that you choose not to tender for exchange, or that we
do not accept for exchange in the Offer, will remain outstanding and retain all
their current terms, including exercise price, term and vesting schedule.


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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What if Regeneron enters into a merger or other similar transaction?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As is generally the case with respect to the option agreements for options
eligible to be tendered in the Offer, the option agreements for replacement
options will include provisions whereby the replacement options may become
fully vested in connection with a &#147;Change in Control&#148; of the Company, as
defined in the 2000 Plan.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We may terminate the Offer before the Expiration Date, if we determine
that it is inadvisable for us to proceed with the Offer or to accept and cancel
options tendered for exchange because a tender or exchange offer with respect
to some or all of our capital stock, or a merger or acquisition proposal for
us, is proposed, announced or made by another person or entity or is publicly
disclosed. Currently, the Company has no plans to enter into a business
combination such as those referred to in the previous sentence. See Section&nbsp;2
&#150; &#147;Purpose and Background of the Offer,&#148; Section&nbsp;6 &#150; &#147;Conditions of the Offer,&#148;
Section&nbsp;8 &#150; &#147;Source and Amount of Consideration; Terms of Replacement Options &#150;
Description of the Material Terms of the 2000 Plan,&#148; and the applicable
replacement option agreement in the form of exhibit (d)(7), (d)(8) or (d)(9),
as applicable, to the Schedule&nbsp;TO.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What happens if the Offer is not consummated?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If we do not accept any options tendered for exchange and not withdrawn,
you will keep all of your current options and you will not receive replacement
options. No changes will be made to your existing options and they will remain
outstanding with their current terms, including exercise price, term and
vesting schedule, until they are exercised or expire by their terms.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>When does the Offer expire? Can the Offer be extended?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer expires on January&nbsp;5, 2005, at 6:00 p.m., Eastern Time, unless
we extend it.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Although we do not currently intend to do so, we may, in our discretion,
extend the Offer at any time. If the Offer is extended, we will provide
appropriate notice of the extension no later than 9:00 a.m., Eastern Time, on
the next business day following the previously scheduled Expiration Date of the
Offer. See Section&nbsp;14 &#150; &#147;Extension of Offer; Termination; Amendment.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>How do I tender my options for exchange in the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In order to validly tender eligible options for exchange in the Offer, you
must, in accordance with the instructions set forth in the Election Form,
properly complete, duly execute and deliver to us the Election Form prior to
the Expiration Date. Delivery of the Election Form must either be by regular
or overnight mail to Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River
Road, Tarrytown, New York 10591, Attention: Human Resources Department,
Options Exchange, or by hand to either Pam Curtis in our Tarrytown, New York
location or Lynne Fuierer in our Rensselaer, New York location.


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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">Delivery by e-mail or other electronic means will not be accepted. We
will only accept a properly executed paper copy of the Election Form.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We reserve the right to reject any or all tenders of options that we
determine are not in appropriate form or that we determine are unlawful to
accept. Otherwise, we expect to accept all eligible options that are properly
and timely tendered for exchange and not validly withdrawn. See Section&nbsp;3 &#150;
&#147;Procedures for Tendering Options for Exchange&#148; and Section&nbsp;4 &#150; &#147;Withdrawal
Rights.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>During what period of time may I withdraw previously tendered options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may withdraw options you tendered for exchange at any time before the
Offer expires at 6:00 p.m., Eastern Time, on the Expiration Date. To withdraw
options tendered for exchange, you must deliver to us prior to the Expiration
Date a properly completed and signed written Notice of Withdrawal in
substantially the form enclosed with this Offer to Exchange. Delivery of the
Notice of Withdrawal must either be by regular or overnight mail to Regeneron
Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591,
Attention: Human Resources Department, Options Exchange, or by hand to either
Pam Curtis in our Tarrytown, New York location or Lynne Fuierer in our
Rensselaer, New York location. Delivery by e-mail or other electronic means
will not be accepted.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Once you have withdrawn options, you may re-tender options for exchange
only by again following the tender procedures described in this Offer to
Exchange and the accompanying Election Form. See Section&nbsp;4 &#150; &#147;Withdrawal
Rights&#148; and Section&nbsp;3 &#150; &#147;Procedures for Tendering Options for Exchange &#150; Proper
Tender of Eligible Options.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Can I change my mind and elect not to tender certain options, or elect to
tender additional options, after I submit an Election Form?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yes. If you submitted an Election Form and you want to withdraw some or
all of the options you marked for tender on that form, you may withdraw your
tender of such options by delivering to us prior to the Expiration Date a
properly completed and signed Notice of Withdrawal (in the form enclosed with
the Offer to Exchange) indicating which options you are withdrawing. If you
wish to tender for exchange additional options that you had not marked for
tender on your previous Election Form, you may elect to tender for exchange
those additional options by delivering to us prior to the Expiration Date an
additional properly completed and signed Election Form (in the form enclosed
with this Offer to Exchange) selecting for tender for exchange such additional
option grants. You may only tender for exchange all options subject to a
particular grant. If you deliver an Election Form or a Notice of Withdrawal
with respect to some but not all options subject to a particular grant, we may,
in our sole discretion, determine that you have elected to tender for exchange
all or none of the options underlying such grant.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may request additional copies of the Notice of Withdrawal or Election
Form by contacting us by phone at (914)&nbsp;345-STOK or by e-mail at
OptionsExchange@regeneron.com. Delivery of the Notice of Withdrawal or the
additional Election Form must either be by regular or overnight mail to
Regeneron



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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York
10591, Attention: Human Resources Department, Options Exchange, or by hand to
either Pam Curtis in our Tarrytown, New York location or Lynne Fuierer in our
Rensselaer, New York location. Delivery by e-mail or other electronic means
will not be accepted. See Section&nbsp;3 &#150; &#147;Procedures for Tendering Options for
Exchange &#150; Proper Tender of Eligible Options&#148; and Section&nbsp;4 &#150; &#147;Withdrawal
Rights.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>When will I receive my replacement options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Promptly after the Expiration Date, we will publicly disclose the
approximate aggregate number of options accepted and canceled in the Offer, the
date of acceptance (which will also be the Grant Date and which we expect will
be on, and in any event will be promptly after, the Expiration Date), the
exercise price per share of the replacement options and the approximate
aggregate number of shares of Common Stock underlying such replacement options.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you participated in the Option Exchange Program, you will receive a
notice from us as soon as practicable after the Grant Date indicating the
number of shares of Common Stock subject to the options you tendered and we
accepted for exchange, the number of shares subject to the replacement option
grant(s) and the exercise price per share of your replacement options. See
Section&nbsp;5 &#150; &#147;Acceptance of Options for Exchange and Grant of Replacement
Options.&#148;


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>After I am granted a replacement option, what happens if that replacement
option ends up &#147;out of the money&#148;?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer is a one-time offer. We do not expect to make the same or a
similar offer in the future. If a replacement option remains &#147;out of the
money&#148; after it vests, and until its expiration, it will then be worthless.
Please note that unlike prior stock options granted under the Stock Incentive
Plans, which generally are valid for up to ten years from the date of grant
(subject to continued employment and the other terms of the plans), your
replacement option will expire on the later of (1)&nbsp;the remaining term of the
tendered option it replaces and (2)&nbsp;six years from the Grant Date. <B>We can
provide no assurance as to the price of our Common Stock in the future and
nothing contained herein or in the documents you receive is a claim as to our
future prospects.</B>


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>What does Regeneron and its board of directors think of the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Although our board of directors has approved the Offer, subject to
shareholder approval of an amendment to the 2000 Plan expressly authorizing the
Option Exchange Program, in light of the unique circumstances of individual
optionholders, as well as the risks associated with the Offer described in this
Offer to Exchange under &#147;Risk Factors&#148; neither we nor our board of directors
makes any recommendation as to whether you should tender or refrain from
tendering your options for exchange. You must make your own decision whether
to tender options. For questions regarding tax implications or other
investment-related questions, you should consult with your own legal counsel,
accountant, financial and tax advisors. See Section&nbsp;2 &#150; &#147;Purpose and
Background of the Offer.&#148;


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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Whom can I talk to if I have questions about my existing options or about the Offer?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;For additional information or assistance concerning the Offer, you should
contact us at Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road,
Tarrytown, New York 10591, Attention: Human Resources Department, Option
Exchange, by phone at (914)&nbsp;345-STOK or at our internal e-mail address:
OptionsExchange@regeneron.com.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>How should I decide whether or not to exchange my eligible options for
replacement options?</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We understand that this may be a difficult decision. There are no
guarantees of our future performance, the future prices of our Common Stock, or
the price of our Common Stock on the Grant Date or thereafter. We advise you
to consult with your financial advisor regarding the relative benefits of
tendering your eligible options for exchange and cancellation pursuant to the
Offer or holding your eligible options at different future market prices for
our Common Stock.


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<P align="center" style="font-size: 10pt"><B>RISK FACTORS</B>



<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><I>Tendering options for exchange in the Offer involves a number of potential
risks, including those described below. You should carefully consider the
risks described below and the risk factors under the caption &#147;Risk Factors&#148; in
our Quarterly Report on Form 10-Q for the quarter ended September&nbsp;30, 2004,
filed with the SEC on November&nbsp;8, 2004. You should consider these risks and
are encouraged to speak with an investment and tax advisor as necessary before
deciding whether or not to tender your options for exchange in the Offer. In
addition, we strongly urge you to read carefully the rest of this Offer to
Exchange, the accompanying Election Form and other documents to which we have
referred you before deciding whether or not to tender options for exchange in
the Offer.</I>


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Your replacement options will have fewer underlying shares of Common Stock than
the eligible options you tender for exchange.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Your replacement options will be exercisable for only a portion of the
total number of shares of Common Stock underlying your existing eligible
options. As a result, depending on the market price of our Common Stock, you
may benefit more from holding your existing eligible options than by exchanging
them for replacement options. We advise you to consult with your financial
advisor regarding the potential benefits of holding your existing eligible
options at different market prices for our Common Stock.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Your replacement options will have a new vesting schedule.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Regardless of the vested status of the eligible options that you tender
for exchange in the Offer, your replacement options will be subject to a new
vesting schedule as described in this Offer to Exchange and the applicable
option agreement. All replacement options will be completely unvested upon
grant. Therefore, subject to the conditions of the applicable option agreement
and the terms of the 2000 Plan, if your employment with us terminates following
the Grant Date, either voluntarily or involuntarily, your replacement options
may be forfeited unvested or you may have a lesser percentage vested interest
in them at the time your employment with us is terminated as compared to your
vested interest in the eligible options you tendered for exchange and which
were cancelled pursuant to the Offer.


<P align="center" style="font-size: 10pt"><B>Tax Related Risks</B>



<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Some or all of your replacement options may not qualify as incentive stock options.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Replacement options granted to our executive vice president and senior
vice presidents will not be incentive stock options. In addition, replacement
options granted to other employees in exchange for incentive stock options
tendered for exchange and accepted pursuant to the Offer may not qualify as
incentive stock options due to certain limitations on the extent to which
options which become exercisable in a given calendar year may be treated as
incentive stock options. To the extent that this occurs, you will not be
eligible for the favorable tax treatment that may be available for incentive
stock options, which generally may be exercised without an immediate tax
liability for the


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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">optionee and which allow the optionee under certain circumstances to
receive capital gains tax treatment upon disposition of the underlying shares.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>If you are a resident of the U.S. but subject to foreign tax laws, there
may be tax and social insurance consequences that may apply to you for
tendering eligible options in exchange for replacement options pursuant to the
Offer. You should be certain to consult your own tax advisors to discuss these
consequences.</B>


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<P align="center" style="font-size: 10pt"><B>THE OFFER</B>



<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Section&nbsp;1. ELIGIBLE OPTIONS AND OPTIONHOLDERS; NUMBER OF REPLACEMENT OPTIONS;
EXPIRATION DATE.</B>


<P align="left" style="font-size: 10pt"><B>Eligible Options and Optionholders.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Upon the terms and subject to the conditions of the Offer, we are offering
to grant options under the 2000 Plan in exchange (at the exchange ratios
described herein) for eligible outstanding options under the Stock Incentive
Plans that are properly tendered by eligible optionholders in accordance with
Section&nbsp;3 (and not validly withdrawn in accordance with Section&nbsp;4) before the
Expiration Date and accepted for exchange by the Company. All outstanding
options owned by eligible optionholders that have an exercise price per share
of $18.00 or more issued under the 2000 Plan or the 1990 Plan are eligible to

be tendered for exchange in the Offer.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You will be an &#147;eligible optionholder&#148; and thus be eligible to tender your
eligible options for exchange and cancellation, and to receive replacement
options, pursuant to the Offer if, on December&nbsp;3, 2004, the date the Offer
commenced, you were a Company regular employee who was actively employed by us
and working an average of at least 20 hours per week, excluding our
non-executive employee director and our president and chief executive officer.
Non-employee directors, consultants, former employees and retirees are also not
eligible optionholders. There are currently approximately 509 eligible
optionholders.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If on the Grant Date a Company regular employee who was an eligible
optionholder on December&nbsp;3, 2004, the date the Offer to Exchange commenced, is
no longer a Company regular employee for any reason, including retirement,
termination, voluntary resignation, layoff, death or disability, that
optionholder will not be an eligible optionholder and will not be eligible to
tender options for exchange and cancellation, or to receive replacement
options, pursuant to the Offer. A Company regular employee who is on an
authorized leave of absence and is otherwise on December&nbsp;3, 2004 and through
the Grant Date, an eligible optionholder, will be an eligible optionholder for
purposes of the Offer. Leave is considered &#147;authorized&#148; if it was approved in
accordance with policies or practices of the Company, as determined by the
Company in its sole discretion (including vacation and short-term leave).


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Tendering eligible options and receiving replacement options in exchange,
pursuant to the Offer does not confer upon you the right to remain an employee
of the Company. The terms of your employment with us remain unchanged. We
cannot guarantee or provide you with any assurance that you will not be subject
to involuntary termination or that you will otherwise remain in the employ of
the Company until the Grant Date or thereafter. If you voluntarily terminate
your employment with us, or if we terminate your employment for any reason,
before the Grant Date, even if you tendered eligible options for exchange in
the Offer prior to such termination, such tender will not be accepted and such
eligible options will not be exchanged for replacement options.


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<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In order to tender an eligible option from a particular option grant, you
must tender all outstanding eligible options under that grant. We are not
accepting partial tenders of particular option grants. For example, if you
hold an option to purchase 1,000 shares of Common Stock at an exercise price of
$19.43 per share, you must tender such option in its entirety; you cannot
tender only part of the option and retain the remainder of the option. On the
other hand, if you have an option to purchase 1,000 shares of Common Stock at
an exercise price of $19.43 per share and an option to purchase 2,000 shares of
Common Stock at an exercise price of $28.01 per share, you may choose to tender
for exchange all (but not less than all) of the outstanding options under
either of the option grants, both of the option grants or neither of the option
grants, provided such options are eligible to be tendered in the Offer.
Similarly, if you have an incentive stock option to purchase 700 shares of
Common Stock at an exercise price of $19.43 and a nonqualified stock option to
purchase 300 shares of Common Stock at $19.43, you may choose to tender for
exchange all (but not less than all) of the outstanding options under either of
the option grants, both of the option grants, or neither of the option grants,
provided such options are eligible to be tendered in the Offer. If you have
previously partially exercised an eligible option grant, you can still tender
for exchange in the Offer the remaining unexercised portion of such eligible
option grant.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following table summarizes information related to the options eligible
to be tendered for exchange in the Offer:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="46%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="6%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Remaining</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number of Shares</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Weighted</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Underlying Eligible</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Weighted Average</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Average Life of</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>Exercise Price Range</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Options as</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exercise Price of</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Eligible Options</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>of Eligible Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>of November 3, 2004</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Eligible Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>(Years)</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:20px; text-indent:-10px">$18.00 - $28.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2,188,294</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">$</TD>
    <TD align="right" valign="top">21.28</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">7.46</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD align="center"><DIV style="margin-left:20px; text-indent:-10px">$28.01 - $37.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1,386,437</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">$</TD>
    <TD align="right" valign="top">28.78</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">6.97</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:30px; text-indent:-10px">$37.01 and up</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1,272,850</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">$</TD>
    <TD align="right" valign="top">40.43</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">5.96</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
    <TD align="center"><DIV style="margin-left:20px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top"><HR size="1" noshade>&nbsp;</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top"><HR size="1" noshade>&nbsp;</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top"><HR size="1" noshade>&nbsp;</TD>
    <TD valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px"><B>Total Number of
Shares Underlying
Eligible Options</B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">4,847,581</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">$</TD>
    <TD align="right" valign="top">28.46</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">6.93</TD>
    <TD valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt"><B>Number of Replacement Options.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If your options are validly tendered for exchange and accepted pursuant to
the Offer, they will be cancelled and you will be entitled to receive
replacement options exercisable for a number of shares of our Common Stock
based on the following exchange ratios:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="70%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="16%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exchange Ratio</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>Exercise Price Range</B></TD>
    <TD nowrap align="center" colspan="5"><B>(number of eligible options to be tendered and</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>of Eligible Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>canceled for each replacement option)</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px">$18.00 - $28.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1.50</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px">$28.01 - $37.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2.00</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:20px; text-indent:-10px">$37.01 and up</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">3.00</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Replacement option grants calculated according to the exchange ratios will
be rounded down to the nearest whole share on a grant-by-grant basis.
Accordingly, options


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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">will not be granted for fractional shares. All replacement options will
be granted under the 2000 Plan and will be subject to the terms of an
applicable replacement option agreement substantially in the form of exhibit
(d)(7), (d)(8) or (d)(9), as applicable, to the Schedule&nbsp;TO.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Of the outstanding options held by eligible employees as of November&nbsp;3,
2004, the maximum number of shares of Common Stock underlying options which
could be tendered for exchange pursuant to the Offer is 4,847,581, and the
maximum number of shares of Common Stock underlying the replacement options
which could be granted in accordance with the exchange ratios set forth in the
table above is approximately 2,576,365. Executive officers who are eligible to
tender eligible options and receive replacement options pursuant to the Offer,
namely all our executive officers other than our president and chief executive
officer (such executive officers collectively referred to as the &#147;Eligible
Officers&#148;), hold collectively as a group 2,085,000 eligible options which, if
validly tendered for exchange in the Offer, would entitle them to 1,063,500
replacement options.


<P align="left" style="font-size: 10pt"><B>Expiration Date.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Offer is scheduled to expire at 6:00 p.m., Eastern Time, on January&nbsp;5,
2005, unless we, in our discretion, extend the period of time during which the
Offer will remain open. See Section&nbsp;14 &#150; &#147;Extension of Offer; Termination;
Amendment,&#148; for a description of our rights to extend, delay, terminate or
amend the Offer.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;2. PURPOSE AND BACKGROUND OF THE OFFER.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We are making the Offer to eligible optionholders for compensatory
purposes. Stock options are generally intended to help align the interests of
a company&#146;s employees with the interests of the company&#146;s shareholders.
Accordingly, a key objective of our Stock Incentive Plans is to encourage
ownership of the Company by personnel whose long-term employment and efforts
are considered important to the Company&#146;s continued progress. The Compensation
Committee of the board of directors, and the board, believe that the Stock
Incentive Plans have proven to be effective tools that encourage stock option
recipients to act in the shareholders&#146; interest by enabling the option
recipients to have an economic stake in the Company&#146;s success.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The price of our Common Stock has declined sharply since 2000. As of
November&nbsp;3, 2004, approximately 54% of the outstanding options granted under
the Stock Incentive Plans had an exercise price above $18 per share. The per
share exercise prices for the annual stock option grants for employees in the
past four years have been $37.78 (in December&nbsp;2000), $28.01 (in December&nbsp;2001),
$19.43 (in December&nbsp;2002), and $13.00 (in December&nbsp;2003). On November&nbsp;3, 2004,
the date as of which option values and exchange ratios were determined for
purposes of the Option Exchange Program, the closing price per share of Common
Stock on The Nasdaq National Market was $7.88. On December&nbsp;1, 2004, the
closing price per share of Common Stock on The Nasdaq National Market was
$9.03. The exercise prices noted above, as compared to current per share
market prices for the Common Stock, illustrate that a substantial number of the
outstanding options granted pursuant to the Stock Incentive Plans are &#147;out


<P align="center" style="font-size: 10pt">17
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">of the money&#148; and no longer serve as effective incentives to retain and
motivate employees. In today&#146;s competitive market for top talent in the
pharmaceutical and biotechnology industries, the Compensation Committee of the
board of directors and the board believe that it is important for the future
success of the Company, and thus for the enhancement of long-term shareholder
value, to revitalize the incentive value of our stock option program as part of
our overall compensation program to retain, motivate and reward employees.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Compensation Committee of the board of directors and the board believe
that, by realigning the exercise prices of employee stock options with current
per share market prices for the Common Stock, the Option Exchange Program, as
implemented through the Offer, will enable the 2000 Plan to again become an
important tool to help motivate the Company&#146;s employees to create shareholder
value. Furthermore, we believe that renewing vesting requirements on the
replacement options should result in increased incentives for employees to
remain with the Company and also reward employees for their continued
dedication and loyalty in the future. In addition, we believe that
establishing the performance vesting criterion for replacement options granted
to our executive vice president and senior vice presidents under the Option
Exchange Program will serve as an important additional incentive for those
individuals to create shareholder value.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The exchange ratios under the Option Exchange Program and the Offer (that
is, how many eligible options an employee must tender for exchange in the Offer
in order to receive one replacement option) were determined in a manner
intended to provide for an exchange based approximately on fair values of
options tendered and replacement options granted, using Black-Scholes models,
with aggregate values favorable to shareholders. The Black-Scholes valuation
methodology, a widely recognized and accepted valuation model to determine the
value of stock options, takes into account a number of variables, including
exercise price, current stock price, stock price volatility, risk-free rate of
return, and the remaining term of the options being valued. In determining the
exchange ratios, the Compensation Committee of the board of directors and the
board considered the advice of Pearl Meyer &#038; Partners, a nationally recognized
compensation consulting firm, including advice with respect to option values
and exchange ratios, and used information available as of the close of business
on November&nbsp;3, 2004 in determining the respective values and amounts of the
variables utilized in the Black-Scholes model.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Except as otherwise disclosed in the Offer to Exchange or in our filings
with the SEC, we presently have no plans or proposals that relate to or would
result in:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(1)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any extraordinary corporate transaction, such
as a merger, reorganization or liquidation, involving us;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(2)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any purchase, sale or transfer of a material
amount of our assets;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(3)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any material change in our present dividend
policy, or our indebtedness or capitalization;</TD>
</TR>



</TABLE>

<P align="center" style="font-size: 10pt">18
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<DIV style="font-family: 'Times New Roman',Times,serif">


<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">


<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(4)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any change in our present board of directors or
senior management, including a change in the number or term
of directors to fill any existing vacancies on the board of
directors, or any change in an executive officer&#146;s material
terms of employment;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(5)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any other material change in our corporate
structure or business;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(6)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our Common Stock not being authorized for
quotation in an automated quotation system operated by a
national securities association;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(7)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our Common Stock becoming eligible for
termination of registration pursuant to Section&nbsp;12(g)(4) of
the Securities Exchange Act of 1934 as amended (the &#147;Exchange
Act&#148;);</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(8)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the suspension of our obligation to file
reports pursuant to Section 15(d) of the Exchange Act;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(9)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the acquisition by any person of any material
amount of our securities or the disposition of any material
amount of our securities; or</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(10)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any change in our Certificate of Incorporation
or By-laws, or any actions which may impede the acquisition
of control of us by any person.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Company has in the past, and may in the future, seek to raise
additional capital by issuing debt securities, shares of common stock or shares
of preferred stock through public offerings or private placements.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Neither we nor our board of directors makes any recommendation as to
whether you should tender some or all of your eligible options for exchange in
the Offer, nor have we authorized any person to make any such recommendation.</B>
Depending on the market price per share of our Common Stock on the Grant Date,
it is possible that the replacement options could have a higher exercise price
than some or all of your current eligible options. In addition, such
replacement options will be completely unvested. Your decision as to whether
or not to tender your options for exchange may be affected by the particular
eligible options (and option agreements) which you hold. You are urged to
evaluate carefully all of the information in the Offer to Exchange and the
documents to which we refer you and to consult your own legal counsel,
accountant, financial and tax advisors.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You must make your own decision whether to tender your options for
exchange in the Offer.


<P align="center" style="font-size: 10pt">19
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt"><B>Section&nbsp;3. PROCEDURES FOR TENDERING OPTIONS FOR EXCHANGE.</B>



<P align="left" style="font-size: 10pt"><B>Proper Tender of Eligible Options.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;To validly tender your options for exchange in the Offer, you must, in
accordance with the instructions set forth in the Election Form, properly
complete, duly execute and deliver to us the Election Form, which must be
received by us as specified below prior to 6:00 p.m., Eastern Time, on the
Expiration Date. Delivery of the Election Form must either be by regular or
overnight mail to Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road,
Tarrytown, New York 10591, Attention: Human Resources Department, Options
Exchange, or by hand to either Pam Curtis in our Tarrytown, New York location
or Lynne Fuierer in our Rensselaer, New York location. Delivery by e-mail or
other electronic means will not be accepted. We will only accept a properly
completed and executed paper copy of the Election Form. We will notify you by
e-mail (or interoffice mail) of our receipt of your Election Form.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you submitted an Election Form and you want to tender for exchange
options under additional option grants that you had not marked for tender on
that form, you may elect to tender for exchange those additional options by
properly delivering to us prior to 6:00 p.m., Eastern Time, on the Expiration
Date an additional properly completed and signed Election Form selecting for
tender for exchange such additional options. You may only tender for exchange
all options subject to a particular grant.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you deliver an Election Form with respect to some but not all options
subject to a particular grant, we may, in our sole discretion, determine that
you have elected to tender for exchange all or none of the options underlying
such grant. You may request additional copies of the Election Form by
contacting us by phone at (914)&nbsp;345-STOK or by e-mail at:
OptionsExchange@regeneron.com.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>The method of delivery of all documents, including the Election Form, is
at the election and risk of the tendering optionholder. </B>If delivery is by
mail, we recommend that you use registered mail with return receipt requested.
In all cases, you should allow sufficient time to ensure timely delivery. Your
options will not be considered tendered until we receive the necessary
documentation. We will not accept delivery by e-mail or other electronic
means.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Determination of Validity; Rejection of Options; Waiver of Defects; No
Obligation to Give Notice of Defects.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We will determine, in our sole discretion, all questions as to form of
documents and the validity, form, eligibility, including time of receipt, and
acceptance of any tender of options for exchange in the Offer. Our
determination of these matters will be final and binding on all parties. <B>We
reserve the right to reject any or all tenders of options that we determine are
not in appropriate form or that we determine are unlawful to accept.</B>
Otherwise, we expect to accept for exchange and cancellation all properly and
timely tendered options which are not validly withdrawn. Subject to applicable
law, including Rule&nbsp;13e-4 of the Exchange Act, we may also waive any of the
conditions of the Offer (other than the shareholder approval condition set
forth in clause (1)&nbsp;of Section


<P align="center" style="font-size: 10pt">20
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">6 - &#147;Conditions of the Offer,&#148; which we will not waive) or any defect or
irregularity in any tender with respect to any particular eligible option or
any particular eligible optionholder. No tender of options will be deemed to
have been properly made until all defects or irregularities have been cured by
the tendering optionholder or waived by us. Neither we, nor any other person,
is obligated to give notice of any defects or irregularities in tenders, and no
one will be liable for failing to give notice of any defects or irregularities.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This is a one-time offer to exchange your eligible options. The Offer
will expire at 6:00 p.m., Eastern Time, on January&nbsp;5, 2005, unless we extend
the Offer. We currently have no plans to repeat the same or a similar offer in
the future.


<P align="left" style="font-size: 10pt"><B>Our Acceptance Constitutes an Agreement.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Your tender of options for exchange pursuant to the procedures described
above constitutes your acceptance of the terms and conditions of the Offer.
Our acceptance for exchange of your options tendered by you pursuant to the
Offer will constitute a binding agreement between you and us upon the terms and
subject to the conditions of the Offer.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Subject to our rights to extend, terminate and amend the Offer, we expect
that we will accept for exchange on, and in any event will be promptly after,
the Expiration Date, all eligible options validly tendered and not validly
withdrawn by eligible optionholders.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;4. WITHDRAWAL RIGHTS.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may only withdraw your options tendered for exchange in accordance
with the provisions of this Section&nbsp;4.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may withdraw some or all of the eligible options you tendered for
exchange in the Offer. If you want to withdraw any of the options you tendered
for exchange, you must withdraw all tendered options for shares of Common Stock
subject to a particular grant. If you deliver a Notice of Withdrawal with
respect to only some but not all of the options subject to a particular grant,
we may, in our sole discretion, determine that you have elected to withdraw all
or none of the options underlying such grant. You may request additional
copies of the Notice of Withdrawal by contacting us by phone at (914)&nbsp;345-STOK
or by e-mail at: OptionsExchange@regeneron.com.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may withdraw your tendered options at any time before 6:00 p.m.,
Eastern Time, on January&nbsp;5, 2005, the currently scheduled Expiration Date of
the Offer. If the Offer is extended by us beyond that time, you may withdraw
your tendered options at any time until the extended Expiration Date of the
Offer. In addition, if we have not accepted your options tendered for exchange
before 12:00 midnight, Eastern Time, on February&nbsp;1, 2005, the 40th business day
following the commencement of the Offer, you may withdraw your options at any
time thereafter. For purposes of the Offer, a &#147;business day&#148; means any day
other than a Saturday, Sunday or U.S. Federal holiday and consists of the time
period from 12:01&nbsp;a.m. through 12:00 midnight, Eastern Time.


<P align="center" style="font-size: 10pt">21
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;To validly withdraw options tendered for exchange in the Offer, you must,
in accordance with the instructions set forth in the Notice of Withdrawal,
properly complete, duly execute and deliver to us the Notice of Withdrawal,
which must be received by us as specified below prior to 6:00 p.m., Eastern
Time, on the Expiration Date. Delivery of the Notice of Withdrawal must either
be by regular or overnight mail to Regeneron Pharmaceuticals, Inc., 777 Old Saw
Mill River Road, Tarrytown, New York 10591, Attention: Human Resources
Department, Options Exchange, or by hand to either Pam Curtis in our Tarrytown,
New York location or Lynne Fuierer in our Rensselaer, New York location.
Delivery by e-mail or other electronic means will not be accepted. We will
only accept a properly completed and executed paper copy of the Notice of
Withdrawal. We will notify you by e-mail (or interoffice mail) of our receipt
of your Notice of Withdrawal.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You may not rescind any withdrawal, and any options you withdraw will
thereafter be deemed not properly tendered for purposes of the Offer, unless
you properly re-tender those options before the Expiration Date by following
the procedures described above in Section&nbsp;3 &#150; &#147;Procedures for Tendering Options
for Exchange &#150; Proper Tender of Eligible Options.&#148;


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Neither we nor any other person is obligated to give you notice of any
defects or irregularities in any notice of withdrawal, nor will anyone incur
any liability for failure to give you any such notice. We will determine, in
our discretion, all questions as to the form and validity, including time of
receipt of Notices of Withdrawal. Our determination of these matters will be
final and binding.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;5. ACCEPTANCE OF OPTIONS FOR EXCHANGE AND GRANT OF REPLACEMENT OPTIONS.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We reserve the right to extend, postpone, amend or terminate the Offer.
However, we expect that, upon the terms and subject to the conditions of the
Offer, on, and in any event promptly after, the Expiration Date, we will accept
for exchange and cancel all validly tendered eligible options that have not
been validly withdrawn. Once we have accepted options validly tendered by you
for exchange, such options will be canceled and you will no longer have any
rights under those options.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;For purposes of the Offer, we will be deemed to have accepted for exchange
options that are validly tendered for exchange and not properly withdrawn if
and when we give written notice to the optionholders of our acceptance for
exchange of such options, which may be by e-mail, press release or other
permitted means. The replacement options will be granted on or as of the date
of such acceptance, which we expect will be on, and in any event will be
promptly after, the Expiration Date. Promptly following the Expiration Date,
we will publicly disclose the approximate aggregate number of shares accepted
and canceled in the Offer, the Grant Date, the exercise price per share of the
replacement options and the approximate aggregate number of shares of Common
Stock subject to replacement options. If and when we accept for exchange and
cancellation your properly tendered options, you will have no further rights
with respect to those cancelled options, and the stock option agreement(s) and
other documentation with respect to such cancelled options will be deemed null
and void. As promptly as


<P align="center" style="font-size: 10pt">22
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">practicable after we accept tendered options for exchange and
cancellation, we will send each tendering optionholder a notice indicating the
number of shares of Common Stock subject to the options tendered for exchange
that we have accepted and cancelled and the number of shares of Common Stock
underlying the replacement options granted in exchange for such options, as
well as a copy of the replacement option agreement (in the applicable form
filed by us as exhibit (d)(7), (d)(8) or (d)(9), as applicable, to the Schedule
TO but with the appropriate blanks filled in and the appropriate bracketed
language deleted) which will be effective from and as of the Grant Date. You
will only receive replacement options for eligible options properly tendered
and not withdrawn which have been accepted for exchange and cancellation
pursuant to the Offer, and which are outstanding as of the Grant Date.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;To receive replacement options in exchange for tendered options, you must
remain an eligible employee of the Company through the Grant Date. If your
employment with the Company ceases for any reason, or you otherwise cease to be
an eligible optionholder, after you tender eligible options but before the
Expiration Date, your tendered options will automatically be withdrawn from the
Offer. If your employment with the Company ceases for any reason, or you
otherwise cease to be an eligible optionholder, after you tender eligible
options and after the Expiration Date but before we accept your tendered
options for exchange and cancellation, your options will not be exchanged. In
both cases, your tendered options will be treated as if they had not been
tendered and you will not receive any replacement options in exchange for such
tendered options. Such options will remain outstanding in accordance with
their terms, subject to the termination provisions contained in your applicable
stock option agreement(s) and the applicable Stock Incentive Plan.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The foregoing requirements apply regardless of the reason your employment
terminates, or you otherwise cease to be an eligible optionholder, including
voluntary resignation, involuntary termination, death or disability.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Eligible options that you choose not to tender for exchange or that we do
not accept for exchange will remain outstanding until they are exercised or
expire by their terms and will retain their current exercise price, term,
vesting schedule and other rights and benefits.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;6. CONDITIONS OF THE OFFER.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We will not be required to accept any options tendered for exchange, and
we may terminate or amend the Offer, or postpone our acceptance and
cancellation of any options tendered for exchange, in each case, subject to
Rule&nbsp;13e-4(f)(5) under the Exchange Act, if, at any time before our acceptance
of options tendered for exchange pursuant to the Offer, we determine that any
of the following events has occurred and, in our reasonable judgment, the
occurrence of the event makes it inadvisable for us to proceed with the Offer
or to accept for exchange options tendered for exchange pursuant to the Offer:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(1)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the proposal to amend the 2000 Plan to expressly authorize
the Option Exchange Program is not approved by the requisite vote of
shareholders at</TD>
</TR>



</TABLE>

<P align="center" style="font-size: 10pt">23
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<DIV style="font-family: 'Times New Roman',Times,serif">


<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">


<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Special Meeting of Shareholders to be held on December&nbsp;17, 2004
or any adjournment or postponement thereof;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(2)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any threatened, instituted or pending action or proceeding by
any government or governmental, regulatory or administrative agency,
authority or tribunal or any other person, domestic or foreign,
before any court, authority, agency or tribunal that directly or
indirectly challenges the making of the Offer, the cancellation of
some or all of the options tendered for exchange, the issuance of
replacement options, or otherwise relates in any manner to the Offer
or that, in our reasonable judgment, could materially and adversely
affect the business, condition (financial or other), income,
operations or prospects of the Company, or otherwise materially
impair in any way the contemplated future conduct of our business;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(3)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any action is threatened, pending or taken, or any approval,
exemption or consent is withheld, or any statute, rule, regulation,
judgment, order or injunction is threatened, proposed, sought,
promulgated, enacted, entered, amended, enforced or deemed to be
applicable to the Offer or us, by or from any court or any
regulatory or administrative authority, agency or tribunal that, in
our reasonable judgment, would or might directly or indirectly:</TD>
</TR>

</TABLE>


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>make the acceptance for exchange of, or grant of
replacement options for, some or all of the tendered options
illegal or otherwise restrict or prohibit consummation of the
Offer or otherwise relates in any manner to the Offer;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>require that we obtain shareholder approval in
addition to the approval sought at the Special Meeting of
Shareholders;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>delay or restrict our ability, or render us unable,
to accept for exchange, or grant replacement options for, some
or all of the tendered options; or</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>materially and adversely affect the business,
condition (financial or other), income, operations or prospects
of the Company, or otherwise materially impair in any way the
contemplated future conduct of our business;</TD>
</TR>

</TABLE>


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(4)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any change or changes occur in our business, condition
(financial or other), assets, income, operations, prospects or share
ownership, including as a result of any changes in law or accounting
principles, or there is any governmental or legal action or
proceeding, law or regulation that, in our reasonable judgment, is
or may be material to us or materially impairs or may materially
impair the benefits, or materially increase the burden, of the Offer
to us;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(5)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>any general suspension of trading in, or limitation on prices
for, securities on any national securities exchange or in the
over-the-counter market;</TD>
</TR>



</TABLE>

<P align="center" style="font-size: 10pt">24
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">


<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">


<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(6)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the declaration of a banking moratorium or any suspension of
payments in respect of banks in the United States, whether or not
mandatory; or</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">(7)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>a tender or exchange offer with respect to some or all of our
capital stock, or a merger or acquisition proposal for us, is
proposed, announced or made by another person or entity or is
publicly disclosed.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;These conditions are for our benefit. We may assert any of these
conditions in our sole discretion regardless of the circumstances giving rise
to them prior to our acceptance for exchange and cancellation of eligible
options tendered pursuant to the Offer. Except for the shareholder approval
condition set forth in clause (1)&nbsp;above, which we will not waive, we may in our
discretion waive any of the above conditions, in whole or in part, at any time
and from time to time, prior to our acceptance for exchange and cancellation of
eligible options tendered pursuant to the Offer, whether or not we waive any
other condition to the Offer. Our failure at any time to exercise any of these
rights will not be deemed a waiver of any such rights. The waiver of any of
these rights with respect to particular facts and circumstances is not a waiver
with respect to any other facts and circumstances. Any determination we make
concerning the events described in this Section&nbsp;6 &#150; &#147;Conditions of the Offer,&#148;
will be final and binding upon everyone.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Section&nbsp;7. PRICE RANGE OF COMMON STOCK UNDERLYING OPTIONS.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Our Common Stock is quoted on The Nasdaq National Market under the symbol
&#147;REGN.&#148; The following table shows, for the periods indicated, the range of
high and low sales prices per share of our Common Stock as reported by The
Nasdaq National Market.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="76%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>High</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Low</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Fiscal Year ended December&nbsp;31, 2002</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">First Quarter</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">30.20</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">19.74</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Second Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">25.40</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">12.21</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Third Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">18.34</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">11.25</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Fourth Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">22.85</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">12.25</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Fiscal Year ended December&nbsp;31, 2003</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">First Quarter</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">21.49</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">7.40</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Second Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">18.78</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">5.77</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Third Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">22.35</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">12.22</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Fourth Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">18.72</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">11.80</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Fiscal Year ending December&nbsp;31, 2004</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">First Quarter</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">17.00</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">12.80</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Second Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">15.85</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">8.53</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Third Quarter </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">10.80</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">6.76</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Fourth Quarter (through December&nbsp;1, 2004) </DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">9.35</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">6.54</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">25
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<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">On December&nbsp;1, 2004, the last reported sale price of our Common Stock on The
Nasdaq National Market was $9.03 per share. <B>We recommend that you obtain
current market quotations for our Common Stock before deciding whether to
tender your options.</B>


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Section&nbsp;8.
SOURCE AND AMOUNT OF CONSIDERATION; TERMS OF REPLACEMENT
OPTIONS.<BR><BR>
Consideration.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We will grant replacement options exercisable for Common Stock under the
2000 Plan in exchange for outstanding eligible options properly tendered and
accepted for exchange by us pursuant to the Offer. The number of shares of
Common Stock underlying the replacement options granted to you will be
calculated based on the exchange ratios described below and arrived at as
described in Section&nbsp;2 &#150; &#147;Purpose and Background of the Offer.&#148; Replacement
option grants calculated according to the exchange ratios will be rounded down
to the nearest whole share on a grant-by-grant basis. Accordingly, replacement
options will not be issued for fractional shares. The exchange ratios are set
forth below:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="80%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="77%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="9%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exchange Ratio</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>Exercise Price Range</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>(number of eligible options to be tendered</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>of Eligible Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>and canceled for each replacement option)</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px">$18.00 - $28.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1.50</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD align="center"><DIV style="margin-left:10px; text-indent:-10px">$28.01 - $37.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2.00</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD align="center"><DIV style="margin-left:20px; text-indent:-10px">$37.01 and up</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">3.00</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Of the outstanding options held by eligible employees as of November&nbsp;3,
2004, the maximum number of shares of Common Stock underlying options which
could be exchanged in the Offer is 4,847,581, and the maximum number of shares
of Common Stock underlying the replacement options which could be issued in
accordance with the exchange ratios set forth in the table above is
approximately 2,576,365. Eligible Officers hold collectively as a group
2,085,000 options which, if exchanged in full, would entitle them to 1,063,500
replacement options.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The grant of replacement options pursuant to the Offer will not create any
contractual or other right of the recipients to receive any future grants of
stock options, restricted stock, other stock rights or any right of continued
employment. However, replacement options granted in exchange for eligible
options tendered for exchange with reload rights will also have reload rights.
See &#147;Description of the Material Terms of the 2000 Plan,&#148; for a description of
reload rights.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Terms of Replacement Options.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;All replacement options will be granted under the 2000 Plan and will be
subject to the terms of a replacement option agreement substantially in the
form of exhibit (d)(7), (d)(8) or (d)(9), as applicable, to the Schedule&nbsp;TO.


<P align="center" style="font-size: 10pt">26
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Each replacement option will be completely unvested upon grant and will
have a term equal to the greater of (1)&nbsp;the remaining term of the tendered
option it replaces and (2)&nbsp;six years from the Grant Date. The term of the
option is the maximum length of time during which it may be exercised.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Each replacement option granted to an employee other than our executive
vice president and senior vice presidents will ordinarily become vested and
exercisable in equal annual installments on each of the first, second, third
and fourth anniversaries of the Grant Date. Each replacement option granted to
our executive vice president and senior vice presidents will ordinarily vest
with respect to all the shares underlying such option if <I>both </I>(1)&nbsp;the Company&#146;s
products have achieved gross sales of at least $100&nbsp;million during any
consecutive twelve month period (either directly by the Company or through its
licensees) <I>and </I>(2)&nbsp;the specific senior or executive vice president has remained
employed by the Company for at least three years from the Grant Date. For all
replacement options, the recipient&#146;s vesting and exercise rights will be
contingent on the recipient&#146;s continued employment through the applicable
vesting dates and subject to the provisions of the 2000 Plan and the applicable
option agreement. As is generally the case with respect to the option
agreements for options eligible for exchange pursuant to the Option Exchange
Program, the option agreements for replacement options will include provisions
whereby the replacement options may become fully vested in connection with a
&#147;Change in Control&#148; of the Company, as defined in the 2000 Plan. Set forth
below is a description of the 2000 Plan and a summary of the certain
differences between the 1990 Plan and the 2000 Plan.


<P align="left" style="font-size: 10pt"><B>Description of the Material Terms of the 2000 Plan.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following description summarizes the material terms of the 2000 Plan
and options granted under that plan. This description is only a summary and is
not complete. We recommend that you review each of the 2000 Plan, the 1990
Plan and the applicable replacement option agreements that have been filed with
the SEC as exhibits to the Schedule&nbsp;TO. The terms and conditions of the Stock
Incentive Plans are also summarized in the prospectus relating to each plan
prepared by us and previously made available to you. You may also contact us
at Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New
York 10591 Attention: Human Resources Department, by phone at (914)&nbsp;345-STOK
or by e-mail at: OptionsExchange@regeneron.com, to request copies of the Stock
Incentive Plans, the form of the replacement option agreement, or the
prospectus relating to each plan, each of which will be provided at our
expense.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>General. </I></B>The Company adopted the 2000 Plan effective June&nbsp;9, 2000 and the
2000 Plan has been subsequently amended to increase the total number of shares
of Common Stock available for issuance under the plan to an aggregate of (i)
18,500,000 plus (ii)&nbsp;shares previously reserved for issuance under the
Company&#146;s 1990 Long-Term Incentive Plan which remained unissued as of June&nbsp;14,
2002 and any shares of Common Stock underlying awards granted under such plan
which are forfeited, expire or cancelled without delivery of shares of Common
Stock. In addition, the 2000 Plan was amended to adjust the date of award of
the automatic grants of options made to non-employee directors.


<P align="center" style="font-size: 10pt">27
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As of November&nbsp;3, 2004, 9,253,339 shares remained available for issuance
under the 2000 Plan and 9,390,229 shares were subject to outstanding awards
(including options eligible to participate in the Option Exchange Program).
The 2000 Plan is scheduled to remain in effect until the close of business on
April&nbsp;24, 2010, unless earlier terminated by the board of directors. Awards
granted under the 2000 Plan (including awards that are issued under the Option
Exchange Program) may remain in effect following the expiration of the term of
the plan in accordance with the award terms. Currently, all regular employees
and directors are eligible to receive grants under the 2000 Plan.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Administration. </I></B>The 2000 Plan is administered by the Compensation
Committee of the board of directors. Each member of the Compensation Committee
is a &#147;non-employee director&#148; (within the meaning of Rule&nbsp;16b-3 promulgated
under Section&nbsp;16 of the Securities Exchange Act of 1934, as amended) and an
&#147;outside director&#148; (within the meaning of Section 162(m) of the Internal
Revenue Code of 1986, as amended). In general, awards granted under the 2000
Plan become exercisable or otherwise vest at the times and upon the conditions
that the Compensation Committee may determine, as reflected in the applicable
award agreement. The Compensation Committee has the authority to accelerate
the vesting and/or exercisability of any outstanding award at such times and
under such circumstances as it, in its sole discretion, deems appropriate (for
instance, upon a &#147;Change in Control&#148; of the Company, as defined in the 2000
Plan). Awards under the 2000 Plan (other than annual grants to non-employee
directors described under &#147;Non-employee Director Awards&#148; below) are generally
made in the discretion of the Compensation Committee.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Types of Awards. </I></B>There are generally four types of awards that may be
granted under the 2000 Plan: Stock options (including both incentive stock
options (referred to as ISOs) within the meaning of Section&nbsp;422 of the Internal
Revenue Code of 1986, as amended and nonqualified stock options (referred to as
NQSOs), which are options that do not qualify as ISOs), Restricted Stock,
Phantom Stock, and Stock Bonus awards. In addition, the Compensation Committee
in its discretion may make other awards valued in whole or in part by reference
to, or otherwise based on, Common Stock.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Adjustment of Shares; Certain Restrictions. </I></B>All of the shares reserved
for issuance under the 2000 Plan are generally subject to equitable adjustment
upon the occurrence of any stock dividend or other distribution,
recapitalization, stock split, reorganization, merger, consolidation,
combination, repurchase or share exchange, or other similar corporate
transaction or event. The maximum number of shares of Common Stock that may be
the subject of awards to a participant in any year is 1,000,000, except that
such number is 1,500,000 with respect to an employee&#146;s initial year of
employment with the Company.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Stock Options. </I></B>Options entitle the holder to purchase shares of Common
Stock during a specified period at a purchase price specified by the
Compensation Committee (but in the case of an ISO, at a price not less than
100% of the fair market value of the Common Stock on the day the ISO is
granted). Each option granted under the 2000 Plan may be exercisable for a
maximum period of 10&nbsp;years from the date of grant. Options may be exercised,
in whole or in part, by the payment of cash of the full option price of


<P align="center" style="font-size: 10pt">28
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">the shares purchased, by tendering shares of Common Stock with a fair
market value equal to the option price of the shares purchased, or by other
methods in the discretion of the Compensation Committee. The 2000 Plan
provides that, unless otherwise determined by the Compensation Committee, an
option shall vest with respect to 20% of the option on the first anniversary of
the date of grant and with respect to an additional 20% on each of the next
four anniversaries thereof. In 2001, the Compensation Committee determined
that, beginning in 2001, options granted under the 2000 Plan would vest ratably
over four years, with 25% of the option vesting on each of the first four
anniversaries of the date of grant. Options which are granted pursuant to the
Option Exchange Program, other than options granted to our executive vice
president and senior vice presidents, shall also vest ratably over a four year
period, with 25% of the option vesting on each of the first four anniversaries
of the date of grant. Each replacement option granted to our executive vice
president and senior vice presidents will ordinarily vest with respect to all
the shares underlying such option if <I>both </I>(1)&nbsp;the Company&#146;s products have
achieved gross sales of at least $100&nbsp;million during any consecutive
twelve-month period (either directly by the Company or through its licensees)
<I>and </I>(2)&nbsp;the specific senior or executive vice president has remained employed
by the Company for at least three years from the date of grant. Options that
are exercisable as of the date of a participant&#146;s termination of service with
the Company may be exercised after such date for the period set forth in the
applicable option agreement or as otherwise determined by the Compensation
Committee. In the event of the death of a participant, any unexercised options
held by such participant are exercisable in accordance with their terms by the
participant&#146;s heirs or personal representatives. Options held by a participant
upon termination from the Company&#146;s service for cause immediately expire
(whether or not then exercisable). The Compensation Committee may provide that
a participant who delivers shares of Common Stock to exercise an option will
automatically be granted new options for the number of shares delivered to
exercise the option (referred to as Reload Options). Reload Options will be
subject to the same terms and conditions as the related option (except that the
exercise price generally will be the fair market value of the Common Stock on
the date the Reload Option is granted). Options with reload rights that are
tendered in the Option Exchange Program will be replaced with options which
also have such reload rights.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Restricted Stock. </I></B>Restricted Stock awards under the 2000 Plan consist of
a grant of shares of restricted Common Stock. The Compensation Committee may
determine the price, if any, to be paid by a participant for each share of
Restricted Stock subject to an award. A holder of Restricted Stock may vote
and, if the participant remains in the service of the Company throughout the
&#147;Restricted Period&#148; as defined in the 2000 Plan, he or she may generally
receive all dividends on all such shares. However, such holder may not
transfer such shares during the Restricted Period. If for any reason during
the Restricted Period a holder of Restricted Stock ceases to be in the service
of the Company, the holder may (and if the termination is on account of cause,
shall) be required to transfer to the Company such Restricted Stock together
with any dividends paid thereon. Consistent with Section 162(m) of the
Internal Revenue Code, the 2000 Plan provides that (i)&nbsp;restrictions on
Restricted Stock may, in the sole discretion of the Compensation Committee,
lapse upon the achievement of certain pre-established performance goals and
(ii)&nbsp;the maximum number of such performance-based Restricted Stock awards that
may be granted to an employee in any year is 200,000.


<P align="center" style="font-size: 10pt">29
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Performance Criteria. </I></B>The 2000 Plan provides that performance goals will
be based on one or more of the following criteria: (1)&nbsp;return on total
shareholder equity; (2)&nbsp;earnings per share of Common Stock; (3)&nbsp;net income
(before or after taxes); (4)&nbsp;earnings before interest, taxes, depreciation and
amortization; (5)&nbsp;revenues; (6)&nbsp;return on assets; (7)&nbsp;market share; (8)&nbsp;cost
reduction goals; (9)&nbsp;any combination of, or a specified increase in, any of the
foregoing; (10)&nbsp;the achievement of certain target levels of discovery and/or
development of products, including without limitation, the regulatory approval
of new products; (11)&nbsp;the achievement of certain target levels of sales of new
products or licensing in or out of new drugs; (12)&nbsp;the formation of joint
ventures, research or development collaborations, or the completion of other
corporate transactions; and (13)&nbsp;such other criteria as the shareholders of the
Company may approve. In addition, such performance goals may be based upon the
attainment of specified levels of Company performance under one or more of the
measures described above relative to the performance of other corporations. To
the extent permitted under Section 162(m) of the Internal Revenue Code of 1986,
as amended (including, without limitation, compliance with any requirements for
shareholder approval), the Compensation Committee may designate additional
business criteria on which the performance goals may be based or may adjust,
modify, or amend the aforementioned business criteria.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Phantom Stock. </I></B>A Phantom Stock award is an award of the right to receive
cash or Common Stock at a future date, subject to such restrictions, if any, as
the Compensation Committee may impose at the date of grant or thereafter, which
restrictions may lapse separately or in combination at such times, under such
circumstances (including without limitation a specified period of employment or
the satisfaction of the performance goals described above), in such
installments, or otherwise, as the Compensation Committee may determine. The
grant of a Phantom Stock award payable solely in cash shall not reduce the
number of shares of Common Stock with respect to which awards may be granted
under the 2000 Plan.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Stock Bonus. </I></B>If the Compensation Committee grants a Stock Bonus award, a
certificate for the shares of Common Stock constituting such Stock Bonus is
issued in the name of the participant to whom such grant was made.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Non-employee Director Awards. </I></B>On the first business day after January 1
of each calendar year, each then serving non-employee director of the Company
is granted a NQSO to purchase 15,000 shares of Common Stock at the fair market
value of such shares at the time of grant; such NQSOs become exercisable as to
33-1/3% of the shares covered thereby on each of the first, second, and third
anniversaries of the date of grant, and expire (if not earlier terminated) on
the tenth anniversary of the date of grant. In addition, a non-employee
director may receive such other awards as are approved by a majority of the
Board.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Other Information. </I></B>The 2000 Plan may be amended by the board of
directors, subject to shareholder approval where necessary to satisfy certain
legal and regulatory requirements. On December&nbsp;1, 2004, the closing price of
the Common Stock on the Nasdaq National Market was $9.03.


<P align="center" style="font-size: 10pt">30
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt"><B>Certain Differences between the 1990 Plan and the 2000 Plan.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Replacement options granted in exchange for options granted under the 1990
Plan will be granted under the 2000 Plan and will have terms and conditions as
set forth in the 2000 Plan and a replacement option agreement substantially in
the form attached as exhibit (d)(7), (d)(8) or (d)(9), as applicable, to the
Schedule&nbsp;TO. While the 1990 Plan permits the Company&#146;s board of directors, or
the committee thereof administering the 1990 Plan, to include provisions in
option agreements that would accelerate the vesting of options granted
thereunder in connection with a &#147;Change in Control&#148; of the Company, as defined
in the 1990 Plan, the option agreements with respect to options granted under
the 1990 Plan did not include such provisions, in contrast to many of the
option agreements with respect to options granted under the 2000 Plan. The
applicable option agreement with respect to replacement options granted under
the 2000 Plan will include such contractual provisions whereby the replacement
options may, without any action by the board of directors or a committee
thereof, become fully vested in connection with a &#147;Change in Control&#148; of the
Company, as defined in the 2000 Plan and the additional terms of such option
agreement. Accordingly, and because this definition differs from that
contained in the 1990 Plan, it is possible that a &#147;Change in Control&#148; of the
Company would result in an acceleration of vesting of replacement options that
would not have occurred with respect to options granted under the 1990 Plan.


<P align="left" style="font-size: 10pt"><B>Certain Federal Income Tax Consequences.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Set forth below is a discussion of certain federal income tax consequences
with respect to options that may be granted pursuant to the 2000 Plan. The
following discussion is a brief summary only, and reference is made to the
Internal Revenue Code of 1986, as amended, and the regulations and
interpretations issued thereunder for a complete statement of all relevant
federal tax consequences. This summary is not intended to be exhaustive and
does not describe state, local, or foreign tax consequences of participation in
the 2000 Plan or in the Option Exchange Program.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Incentive Stock Options. </I></B>In general, no taxable income is realized by a
participant upon the grant of an ISO. If shares of Common Stock are issued to
a participant (&#147;Option Shares&#148;) pursuant to the exercise of an ISO granted
under the 2000 Plan and the participant does not dispose of the Option Shares
within the two-year period after the date of grant or within one year after the
receipt of such Option Shares by the participant (a &#147;disqualifying
disposition&#148;), then, generally (i)&nbsp;the participant will not realize ordinary
income upon exercise and (ii)&nbsp;upon sale of such Option Shares, any amount
realized in excess of the exercise price paid for the Option Shares will be
taxed to such participant as capital gain (or loss). With respect to the
replacement options, this two year period will commence as of the Grant Date,
regardless of the date of grant of the options tendered for exchange. The
amount by which the fair market value of the Common Stock on the exercise date
of an ISO exceeds the purchase price generally will constitute an item which
increases the participant&#146;s &#147;alternative minimum taxable income.&#148; If Option
Shares acquired upon the exercise of an ISO are disposed of in a disqualifying
disposition, the participant generally would include in ordinary income in the
year of disposition an amount equal to the excess of the fair market value of
the Option Shares at the time of exercise (or, if less, the amount realized on
the disposition of


<P align="center" style="font-size: 10pt">31
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">the Option Shares), over the exercise price paid for the Option Shares.
Subject to certain exceptions, an ISO generally will not be treated as an ISO
if it is exercised more than three months following termination of employment.
If an ISO is exercised at a time when it no longer qualifies as an ISO, such
option will be treated for tax purposes as an NQSO as discussed below.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Nonqualified Stock Options. </I></B>In general, no taxable income is realized by
a participant upon the grant of an NQSO. Upon exercise of an NQSO, the
participant generally would include in ordinary income at the time of exercise
an amount equal to the excess, if any, of the fair market value of the Option
Shares at the time of exercise over the exercise price paid for the Option
Shares. In the event of a subsequent sale of Option Shares received upon the
exercise of an NQSO, any appreciation or depreciation after the date on which
taxable income is realized by the participant in respect of the option exercise
will be taxed as capital gain in an amount equal to the excess of the sale
proceeds for the Option Shares over the participant&#146;s basis in such Option
Shares. The participant&#146;s basis in the Option Shares will generally equal the
amount paid for the Option Shares plus the amount included in ordinary income
by the participant upon exercise of the NQSO described in the immediately
preceding paragraph.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;9. INFORMATION CONCERNING REGENERON PHARMACEUTICALS, INC.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Regeneron Pharmaceuticals, Inc. is a biopharmaceutical company that
discovers, develops, and intends to commercialize pharmaceutical products for
the treatment of serious medical conditions. Our clinical and preclinical
pipeline includes product candidates for the treatment of cancer, diseases of
the eye, rheumatoid arthritis and other inflammatory conditions, allergies,
asthma, obesity and other diseases and disorders. Developing and
commercializing new medicines entails significant risk and expense. Since
inception we have not generated any sales or profits from the commercialization
of any of our product candidates.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Our clinical candidates, as of September&nbsp;30, 2004, include VEGF Trap,
Interleukin-1 Trap (IL-1 Trap), Interleukin-4/Interleukin-13 Trap (IL-4/13
Trap) and AXOKINE&#174;. VEGF Trap is a protein-based product candidate designed to
bind Vascular Endothelial Growth Factor (called VEGF, also known as Vascular
Permeability Factor or VPF) and the related Placental Growth Factor (called
PlGF), and prevent their interaction with cell surface receptors. VEGF (and to
a less validated degree, PlGF) is required for the growth of new blood vessels
that are needed for tumors to grow and is a potent regulator of vascular
permeability and leakage. IL-1 Trap is a protein-based product candidate
designed to bind the interleukin-1 (called IL-1) cytokine and prevent its
interaction with cell surface receptors. IL-1 is thought to play an important
role in rheumatoid arthritis and other inflammatory diseases. IL-4/13 Trap is
a protein-based product candidate designed to bind both the interleukin-4 and
interleukin-13 (called IL-4 and IL-13) cytokines and prevent their interaction
with cell surface receptors. IL-4 and IL-13 are thought to play a major role
in diseases such as asthma, allergic disorders, and other inflammatory
diseases. AXOKINE&#174; is a protein-based product candidate designed


<P align="center" style="font-size: 10pt">32
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">to act on the brain region regulating appetite and energy expenditure.
AXOKINE&#174; is being developed for the treatment of obesity.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Our core business strategy is to combine our strong foundation in basic
scientific research and discovery-enabling technology with our manufacturing
and clinical development capabilities to build a successful, integrated
biopharmaceutical company. Our efforts have yielded a diverse and growing
pipeline of product candidates that have the potential to address a variety of
serious medical conditions. We believe that our ability to develop product
candidates is enhanced by the application of our technology platforms. These
platforms are designed to discover specific genes of therapeutic interest for a
particular disease or cell type and validate targets through high-throughput
production of mammalian models. We continue to invest in the development of
enabling technologies to assist in our efforts to identify, develop and
commercialize new product candidates. Our web address is www.regeneron.com.
You should not consider the information on our website to be a part of the
Offer.


<P align="left" style="font-size: 10pt"><B>Stock Ownership of Certain Beneficial Owners.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Set forth below is the name, address, and stock ownership of each person
or group of persons known by the Company to own beneficially more than 5% of
the outstanding shares of Common Stock and Class&nbsp;A Stock as of November&nbsp;3,
2004.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="53%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="13%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="7%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="7%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Percentage of Common</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Number of Shares of</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number of Shares of</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Stock and Class A</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Name and Address</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Class A Stock</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Common Stock</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Stock</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>of Beneficial Owner</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Beneficially Owned<SUP>1</SUP></B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Beneficially Owned<SUP>2</SUP></B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Beneficially Owned<SUP>3</SUP></B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Leonard S. Schleifer, M.D., Ph.D.<BR>
c/o Regeneron, Inc.<BR>
777 Old Saw Mill River Road<BR>
Tarrytown, NY 10591</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">1,769,340<SUP>4</SUP></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1,138,877<SUP>5</SUP></TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">5.1</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="padding-top: 0em">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Novartis Pharma AG<BR>
Lichstrasse 35<BR>
CH-4002 Basel, Switzerland</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">7,527,050<SUP>6</SUP></TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">13.5</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="padding-top: 0em; background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">FMR Corp.<BR>
82 Devonshire Street<BR>
Boston, Massachusetts 02109</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">6,381,228<SUP>7</SUP></TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">11.4</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="padding-top: 0em">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Kedge Capital Funds Limited,<BR>
Special Situations 1 Fund<BR>
Lord Coutanche House<BR>
66-68 Esplanade St. Helier<BR>
Jersey (Channel Islands)<BR>
JE4 5YQ</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">4,000,000<SUP>8</SUP></TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">7.2</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="padding-top: 0em; background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Amgen Inc.<BR>
One Amgen Center Drive<BR>
Thousand Oaks, California 91320</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">3,181,309<SUP>9</SUP></TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">5.7</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="padding-top: 0em">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Aventis Pharmaceuticals Inc.<BR>
300 Somerset Corporate Boulevard<BR>
Bridgewater, New Jersey 08807</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2,799,552<SUP>10</SUP></TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">5.0</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>





<P>
<HR size="1" width="18%" align="left" noshade>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>1</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">We calculated beneficial ownership in accordance with the rules of the SEC.
The calculation includes shares subject to options held by the person or
entity in question that are exercisable currently or with in sixty days of
November&nbsp;3, 2004.</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">33
</DIV>

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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">





<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>2</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">We calculated beneficial ownership in accordance with the rules of the
SEC. The calculation includes shares subject to options held by the
person or entity in question that are exercisable currently or with in
sixty days of November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>3</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">To calculate percentage, number of shares outstanding includes 55,741,696
shares of Common Stock outstanding as of November&nbsp;3, 2004, plus any shares
subject to options held by the person or entity in question that are
currently exercisable or exercisable within sixty days after November&nbsp;3,
2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>4</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 58,550 shares of Class&nbsp;A Stock held directly by, or in trust for
the benefit of, Dr.&nbsp;Schleifer&#146;s two sons, of which Dr.&nbsp;Schleifer disclaims
beneficial ownership. Excludes 6,500 shares of Class&nbsp;A Stock held by the
Schleifer Family Foundation, a charitable foundation, of which Dr.
Schleifer disclaims beneficial ownership.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>5</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 1,025,380 shares of Common Stock purchasable upon the exercise
of options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 2,293
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan. Includes 1,800 shares of Common Stock held directly by, or
in trust for the benefit of, Dr.&nbsp;Schleifer&#146;s two sons, of which Dr.
Schleifer disclaims beneficial ownership. Excludes 10,000 shares of
Common Stock held by the Schleifer Family Foundation, a charitable
foundation, of which Dr.&nbsp;Schleifer disclaims beneficial ownership.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>6</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Based on Schedule&nbsp;13G filed by Novartis Pharma AG with the SEC on April
8, 2003.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>7</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Based on Schedule&nbsp;13G/A filed by FMR Corp. with the Securities and
Exchange.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>8</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Based on Schedule&nbsp;13G/A filed by Kedge Capital Funds Limited Special
Situations 1 Fund with the SEC on February&nbsp;13, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>9</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Based on Schedule&nbsp;13G/A filed by Amgen Inc. with the SEC on May&nbsp;5, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>10</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Based on Schedule&nbsp;13G filed by Aventis Pharmaceuticals Inc. with the SEC
on September&nbsp;12, 2003.</TD>
</TR>

</TABLE>



<P align="left" style="font-size: 10pt"><B>Security Ownership of Management.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following table sets forth, as of November&nbsp;3, 2004, the number of
shares of Common Stock and Class&nbsp;A Stock beneficially owned by each of our
directors, each of our named executive officers, who include our Chief
Executive Officer, Leonard S. Schleifer, and the four most highly compensated
executive officers other than our Chief Executive Officer, and all directors
and executive officers as a group, and the percentage that such shares
represent of the total combined number of shares of outstanding Common Stock
and Class&nbsp;A Stock, based upon information obtained from such persons.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="52%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="9%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number of Shares</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number of Shares</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Percentage of Common</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>of Class A Stock</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>of Common Stock</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Stock and Class A Stock</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Name and Address of Beneficial Owner (1)</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Beneficially Owned (2, 3)</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Beneficially Owned (2, 3)</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Beneficially Owned (4)</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Leonard S. Schleifer, M.D., Ph.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">1,769,340</TD>
    <TD align="left" valign="top">(5)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1,138,877</TD>
    <TD nowrap valign="top">(10)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">5.1</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">P. Roy Vagelos, M.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2,499,509</TD>
    <TD nowrap valign="top">(11)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">4.4</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Charles A. Baker</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">62,384</TD>
    <TD nowrap valign="top">(6)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">110,590</TD>
    <TD nowrap valign="top">(12)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Michael S. Brown, M.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">58,049</TD>
    <TD align="left" valign="top">(7)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">148,258</TD>
    <TD nowrap valign="top">(13)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Alfred G. Gilman, M.D., Ph.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">76,237</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">168,975</TD>
    <TD nowrap valign="top">(14)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Joseph L. Goldstein, M.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">52,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">135,000</TD>
    <TD nowrap valign="top">(15)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Arthur F. Ryan</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">13,334</TD>
    <TD nowrap valign="top">(15)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Eric M. Shooter, Ph.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">79,911</TD>
    <TD align="left" valign="top">(8)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">100,000</TD>
    <TD nowrap valign="top">(15)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">George L. Sing</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">172,772</TD>
    <TD nowrap valign="top">(16)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">George D. Yancopoulos, M.D., Ph.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">42,750</TD>
    <TD nowrap valign="top">(9)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1,319,084</TD>
    <TD nowrap valign="top">(17)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2.4</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Murray A. Goldberg</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">276,108</TD>
    <TD nowrap valign="top">(18)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Randall G. Rupp, Ph.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">215,391</TD>
    <TD nowrap valign="top">(19)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Neil Stahl, Ph.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">0</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">355,482</TD>
    <TD nowrap valign="top">(20)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">*</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">All Directors and Executive Officers
as a Group (15 persons)</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">2,140,671</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">6,900,692</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">14.7</TD>
    <TD nowrap valign="top">%</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>




<P>
<HR size="1" width="18%" align="left" noshade>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right">*</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Represents less than 1%</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">34
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">





<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>1</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Unless otherwise stated, the address for each beneficial owner is c/o
Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown,
NY 10591.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>2</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">We calculated beneficial ownership in accordance with the rules of the
Securities and Exchange Commission. The inclusion herein of any Class&nbsp;A
Stock or Common Stock, as the case may be, deemed beneficially owned does
not constitute an admission of beneficial ownership of those shares.
Unless otherwise indicated, each person listed has sole voting and
investment power with respect to the shares listed.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>3</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Number of shares includes number of options held by the person or entity
in question that are currently exercisable or excisable within sixty days
after November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>4</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">To calculate percentage, number of shares outstanding includes 55,741,696
shares outstanding as of November&nbsp;3, 2004 plus any shares subject to
options held by the person or entity in question that are currently
exercisable or exercisable within sixty days after November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>5</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 58,550 shares of Class&nbsp;A Stock held directly by, or in trust for
the benefit of, Dr.&nbsp;Schleifer&#146;s two sons, of which Dr.&nbsp;Schleifer disclaims
beneficial ownership. Excludes 6,500 shares of Class&nbsp;A Stock held by the
Schleifer Family Foundation, a charitable foundation, of which Dr.
Schleifer disclaims beneficial ownership.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>6</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">All shares of Class&nbsp;A Stock are held by a limited partnership.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>7</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 2,700 shares of Class&nbsp;A stock held in trust for the benefit of
Dr.&nbsp;Brown&#146;s daughter.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>8</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">All shares of Class&nbsp;A Stock are held in trust for the benefit of Dr.
Shooter&#146;s children (the Shooter Family Trust).</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>9</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 19,383 shares of Class&nbsp;A Stock held in trust for the benefit of
Dr.&nbsp;Yancopoulos&#146;s children and excludes 205 shares held by Dr.
Yancopoulos&#146;s wife. Dr.&nbsp;Yancopoulos disclaims beneficial ownership of all
such shares.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>10</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 1,025,320 shares of Common Stock purchasable upon the exercise
of options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 2,293
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan. Includes 1,800 shares of Common Stock held directly by, or
in trust for the benefit of, Dr.&nbsp;Schleifer&#146;s two sons, of which Dr.
Schleifer disclaims beneficial ownership. Excludes 10,000 shares of
Common Stock held by the Schleifer Family Foundation, a charitable
foundation, of which Dr.&nbsp;Schleifer disclaims beneficial ownership.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>11</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 1,514,999 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 851
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan. Includes 527,322 shares of Common Stock held in a
charitable trust and 456,337 shares of Common Stock held in three separate
grantor trusts. Excludes 203,199 shares of Common Stock held by the
Marianthi Foundation, and 161,443 shares of Common Stock held by the
Pindaros Foundation, both charitable foundations, of which Dr.&nbsp;Vagelos
disclaims beneficial ownership.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>12</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 110,000 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>13</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 143,000 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>14</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 145,000 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>15</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">All shares of Common Stock beneficially owned represent shares of Common
Stock purchasable upon the exercise of options granted pursuant to the
Stock Incentive Plans which are exercisable or become so within sixty days
from November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>16</sup></TD>
    <TD width="3%">&nbsp;</TD>

    <TD width="96%">Includes 100,000 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>17</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 1,255,200 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 2,266
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>18</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 246,781 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 2,293
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>19</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 204,000 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 2,248
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><sup>20</sup></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Includes 340,000 shares of Common Stock purchasable upon exercise of
options granted pursuant to the Stock Incentive Plans which are
exercisable or become so within sixty days from November&nbsp;3, 2004 and 2,211
shares of Common Stock held in an account under the Company&#146;s 401(k)
Savings Plan.</TD>
</TR>

</TABLE>



<P align="left" style="font-size: 10pt"><B>Summary Financial Information.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Before deciding whether to tender your options for exchange in the Offer,
we encourage you to review the financial information included in our Annual
Report on Form 10-K for the fiscal year ended December&nbsp;31, 2003 and our
Quarterly Report on


<P align="center" style="font-size: 10pt">35
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">Form&nbsp;10-Q for the fiscal quarter ended September&nbsp;30, 2004. See Section&nbsp;17
&#150; &#147;Additional Information,&#148; beginning on page 43, for instructions on how you
can obtain copies of our filings with the SEC, including our filings that
contain our financial statements.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Summary Financial Data. </I></B>The following table summarizes certain of our
financial data and should be read in conjunction with our financial statements
included in our SEC filings.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="49%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="7"><B>For the Nine Months Ended</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="7"><B>For the Year Ended December 31,</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="7"><B>September 30,</B><HR size="1" noshade></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2002</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2003</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2003</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2004</B><HR size="1" noshade></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="15"><B>In thousands, except per share data</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px"><B>Statement of Operations Data</B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Revenues</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Contract research and development</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">10,924</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">47,366</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">28,245</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">94,377</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Research progress payments</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">17,770</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Contract manufacturing</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">11,064</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">10,131</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">7,980</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">14,780</TD>
    <TD>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">21,988</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">57,497</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">36,225</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">126,927</TD>
    <TD>&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Expenses</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Research and development</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">124,953</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">136,024</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">102,757</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">101,306</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Contract manufacturing</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">6,483</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">6,676</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">5,769</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">11,740</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">General and administrative</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">12,532</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">14,785</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">10,548</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">12,209</TD>
    <TD>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">143,968</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">157,485</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">119,074</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">125,255</TD>
    <TD>&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>

    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Income (loss)&nbsp;from operations</DIV></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(121,980</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(99,988</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(82,849</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">1,672</TD>
    <TD>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Other income (expense)</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Other contract income</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">42,750</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Investment income</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">9,462</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">4,462</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">3,594</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">3,646</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Interest expense</DIV></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(11,859</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(11,932</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(8,826</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(9,161</TD>
    <TD nowrap>)</TD>
</TR>

<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(2,397</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(7,470</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(5,232</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">37,235</TD>
    <TD>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Net income (loss)</DIV></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(124,377</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(107,458</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">(88,081</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">38,907</TD>
    <TD>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="4" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="4" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="4" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="4" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Net income (loss)&nbsp;per share:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Basic</DIV></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">($2.83</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">($2.13</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">($1.80</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">0.70</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Diluted</DIV></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">($2.83</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">($2.13</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right">&nbsp;</TD>
    <TD align="right">($1.80</TD>
    <TD nowrap>)</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">0.69</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Weighted average shares outstanding:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Basic</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">43,918</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">50,490</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">48,926</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">55,378</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:20px; text-indent:-10px">Diluted</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">43,918</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">50,490</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">48,926</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">56,295</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="56%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="7"><B>As of December 31,</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="7"><B>As of September 30,</B><HR size="1" noshade></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2002</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2003</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2003</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2004</B><HR size="1" noshade></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="15"><B>In thousands, except per share data</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px"><B>Balance Sheet Data</B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Cash, cash equivalents, marketable securities,
and restricted marketable securities</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">295,246</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">366,566</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">391,123</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">361,184</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Current assets</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">276,948</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">320,207</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">404,378</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">311,238</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Noncurrent assets</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">114,626</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">159,348</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">96,123</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">161,447</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Total assets</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">391,574</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">479,555</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">500,501</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">472,685</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Current liabilities</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">40,118</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">72,923</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">54,736</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">35,900</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Long term notes payable</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">200,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">200,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">200,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">200,000</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Other noncurrent liabilities</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">5,475</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">68,989</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">89,563</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">57,912</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Total stockholders&#146; equity</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">145,981</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">137,643</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">156,202</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">178,873</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Book value per share (A)</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">3.30</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">2.48</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">2.83</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">3.22</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right">(A)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Book value per share is computed by dividing stockholders&#146; equity by the number of shares of Common Stock outstanding at the end of period
presented.</TD>
</TR>


</TABLE>

<P align="center" style="font-size: 10pt">36
</DIV>

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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">



</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Ratio of Earnings to Fixed Charges. </I></B>The following table sets forth our
ratio of earnings to fixed charges for our fiscal years ended December&nbsp;31, 2002
and 2003 and for the nine months ended September&nbsp;30, 2003 and 2004. For our
fiscal years ended December&nbsp;31, 2002 and 2003 and for the nine months ended
September&nbsp;30, 2003, earnings were inadequate to cover the combined fixed
charges, therefore we have provided the coverage deficiency amounts. For
purposes of computing these ratios, earnings represents net income (loss)
before income taxes plus fixed charges. Fixed charges represent interest
expense, capitalized interest, amortization of deferred financing costs, and
such portion of rental expense deemed representative of the interest factor.
The denominator is increased for preferred stock dividend requirements, if any,
which represent the amount of pre-tax earnings required to cover such dividend
requirements. We had no preferred stock outstanding for any of the periods
presented.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="49%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="5"><B>For the Nine Months Ended</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>For the Year Ended December 31,</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="5"><B>September 30,</B><HR size="1" noshade></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>2002</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>2003</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>2003</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>2004</B><HR size="1" noshade></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="9"><B>Dollars in thousands</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Earnings to fixed charges ratio</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(A)</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(A)</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(A)</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">4.43</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Coverage deficiency</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">$124,572</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">$107,638</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">$88,305</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">N/A</TD>
    <TD valign="top">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right">(A)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Due to the Company&#146;s losses for the years ended December&nbsp;31, 2002 and
2003 and for the nine months ended September&nbsp;30, 2003, the coverage ratio
was less than 1:1. The coverage deficiency for these periods represents
the additional earnings necessary for the Company to achieve a coverage
ratio of 1:1.</TD>
</TR>

</TABLE>


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Section&nbsp;10. INTERESTS OF DIRECTORS AND OFFICERS; TRANSACTIONS AND ARRANGEMENTS.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A list of our directors and executive officers is attached to this Offer
to Exchange as Schedule&nbsp;A. Except for our president and chief executive
officer, all of our executive officers are Eligible Officers and thus are
eligible to tender eligible options in exchange for replacement options
pursuant to the Offer. Our directors who are not executive officers (referred
to as non-executive directors) are not eligible optionholders and thus are not
eligible to tender options in the Offer. As of November&nbsp;19, 2004, our
executive officers and directors as a group beneficially owned options
outstanding under the Stock Incentive Plans to purchase a total of 7,276,910
shares of our Common Stock, which represented approximately 57% of the shares
of Common Stock subject to all options outstanding under the Stock Incentive
Plans as of that date. As of November&nbsp;19, 2004, our Eligible Officers, as a
group, held outstanding options under the Stock Incentive Plans to purchase a
total of 3,458,531 shares of our Common Stock, which represented approximately
27% of the shares of Common Stock subject to all options outstanding under the
Stock Incentive Plans as of that date. Of these, options to purchase a total
of 2,085,000 shares of our Common Stock are eligible to be tendered for
exchange pursuant to the Offer.


<P align="center" style="font-size: 10pt">37
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following table shows the number of shares of our Common Stock subject
to options beneficially owned by each of our Eligible Officers and the
respective weighted average exercise prices of those options:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="44%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="6%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="6%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Weighted Average</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number of Shares</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Weighted Average</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number of Shares</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exercise Price of</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Subject to Eligible</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exercise Price of</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Name of Eligible Officer</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Subject to Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>all Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Eligible Options</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Murray A. Goldberg <SUP>(1)</SUP></DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">353,531</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">17.73</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">150,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">27.18</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Stuart Kolinski, Esq.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">210,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">21.12</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">110,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">28.50</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">William Roberts, M.D.</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">160,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">16.29</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">65,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">27.72</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Randall G. Rupp, Ph.D.<SUP>(1)</SUP></DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">280,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">16.49</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">110,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">26.78</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">Neil Stahl, Ph.D.<SUP>(1)</SUP></DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">500,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">18.58</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">250,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">26.53</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">George D. Yancopoulos,
M.D., Ph.D.<SUP>(1)</SUP></DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">1,955,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">26.33</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">1,400,000</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">$</TD>
    <TD align="right">32.58</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right"><SUP>(1)</SUP></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>As noted below, replacement options granted to these individuals, if any,
will be nonqualified stock options and will differ from replacement
options granted to other employees with respect to their vesting terms.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The terms of replacement options that will be granted to our executive
vice president and our senior vice presidents in exchange for any eligible
options tendered by them and accepted by us pursuant to the Offer will have
identical terms as replacement options granted to other eligible optionholders
in exchange for eligible options tendered by them and accepted by us pursuant
to the Offer, except that replacement options to be granted to these members of
senior management, if any, will not constitute incentive stock options and will
contain a different vesting schedule as described in Section&nbsp;8 &#150; &#147;Source and
Amount of Consideration; Terms of Replacement Options &#150; Terms of Replacement
Options.&#148; We believe that establishing the performance vesting criterion for
replacement options granted to our executive vice president and senior vice
presidents will serve as an important additional incentive to create
shareholder value.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In the 60&nbsp;days prior to and including December&nbsp;3, 2004, our directors and
executive officers of Regeneron had no transactions related to the purchase and
sale of our Common Stock other than the exercise and sale in October&nbsp;2004 by
Dr.&nbsp;Rupp, our Senior Vice President, Manufacturing and Process Sciences of
50,000 stock options previously granted to Dr.&nbsp;Rupp that were due to expire on
October&nbsp;17, 2004.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Except as otherwise described above and grants of stock options to
employees who are not directors or executive officers, there have been no
transactions in our Common Stock or in options to purchase our Common Stock
that were effected during the past 60&nbsp;days by us or, to our knowledge, by any
director, executive officer, or affiliate of Regeneron. In addition, except as
otherwise described above and other than restricted stock awards and
outstanding options to purchase Common Stock granted from time to time to
certain of our employees (including executive officers) and non-employee
directors pursuant to the Stock Incentive Plans, neither we nor any person
controlling us nor, to our knowledge, any of our directors or executive
officers, is a party to any


<P align="center" style="font-size: 10pt">38
</DIV>

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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">contract, arrangement, understanding or relationship with any other person
relating, directly or indirectly, to the Offer with respect to any of our
securities (including, but not limited to, any contract, arrangement,
understanding or relationship concerning the transfer or the voting of any such
securities, joint ventures, loan or option arrangements, puts or calls,
guarantees of loans, guarantees against loss or the giving or withholding of
proxies, consents or authorizations). In addition, while our non-executive
directors and our president and chief executive officer are not eligible to
participate in the Option Exchange Program, we expect that these individuals
and many employees eligible to participate in the Option Exchange Program will,
consistent with the Company&#146;s past practice, receive annual stock option grants
in December&nbsp;2004 or, in the case of our non-executive directors, in January
2005.


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt"><B>Section&nbsp;11. STATUS OF OPTIONS TENDERED IN THE OFFER; ACCOUNTING CONSEQUENCES OF THE OFFER.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Options tendered for exchange and accepted by us pursuant to the Offer
will be canceled and the shares of Common Stock subject to those options will
be returned to the pool of shares available for grants under the 2000 Plan.
Once your options have been canceled, you will no longer have any rights under
those options. To the extent such shares are not fully reserved for issuance
in connection with the replacement options to be granted in connection with the
Offer, the shares will be available for future awards to employees and other
eligible participants under the 2000 Plan.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In connection with the Offer, the Company intends to adopt, effective
January&nbsp;1, 2005, the fair value based method of accounting for stock-based
employee compensation under the provisions of Statement of Financial Accounting
Standards No.&nbsp;123, <I>Accounting for Stock-Based Compensation </I>(&#147;SFAS No.&nbsp;123&#148;), as
modified by Statement of Financial Accounting Standards No.&nbsp;148, <I>Accounting for
Stock Based Compensation &#151; Transition and Disclosure </I>(&#147;SFAS No.&nbsp;148&#148;), using
the modified prospective method. In accordance with SFAS Nos. 123/148, upon
the grant of a replacement option pursuant to the Offer, the Company will incur
compensation cost that will be recognized over the vesting period of the
replacement option. The compensation cost will equal the sum of (i)&nbsp;the
unamortized fair value of the tendered options on the date of the exchange and
(ii)&nbsp;the incremental value of the replacement option measured as the difference
between (a)&nbsp;the fair value of the replacement option on the date of the
exchange and (b)&nbsp;the fair value of the tendered options immediately prior to
the exchange. Due to a number of factors, including but not limited to our
inability to predict how many optionholders will exchange their options, which
options will be exchanged, the vesting date of any replacement option granted
to our executive vice president and senior vice presidents, or what the future
market price of our Common Stock will be on the date of the grant of the
replacement option or thereafter, we cannot predict the precise compensation
cost that will be recorded by the Company as a result of the Offer. Assuming,
solely as an example, that all eligible options are exchanged and replacement
options are granted at an exercise price equal to the fair market value (as
calculated in accordance with the 2000 Plan) of the Company&#146;s Common Stock as
of November&nbsp;3, 2004 and that replacement options granted to our executive vice
president and senior vice presidents will ordinarily vest four years from the
date of grant, under SFAS Nos. 123/148 the Company would


<P align="center" style="font-size: 10pt">39
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<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">incur compensation cost totaling approximately $13&nbsp;million related to the
Offer, which would be recognized as an expense over the vesting period of the
replacement options. We would begin recognizing this compensation cost in the
first quarter of 2005 in each of the categories of expense in the Company&#146;s
Statement of Operations.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The adoption of SFAS Nos. 123/148 using the modified prospective method
does not require restatement of prior period data. The financial statement
impact of SFAS No.&nbsp;123 has been presented by the Company in footnote
disclosures in prior filings on Forms 10-K and 10-Q with the SEC. In addition,
the Financial Accounting Standards Boards (&#147;FASB&#148;) has proposed to modify SFAS
No.&nbsp;123, and issuance of the final standard is expected by the end of 2004.
Therefore, the Company may be required to adopt the FASB modification of SFAS
No.&nbsp;123 effective January&nbsp;1, 2005 which could change the Company&#146;s compensation
cost related to the Offer calculated as described above.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;12. LEGAL MATTERS; REGULATORY APPROVALS.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We are not aware of any license or regulatory permit that appears to be
material to our business that might be adversely affected by the cancellation
of options and grant of replacement options as contemplated by the Offer, or of
any approval or other action by any government or governmental, administrative
or regulatory authority or agency, domestic or foreign, that would be required
for the acquisition or ownership of our replacement options as contemplated
herein. Should any such approval or other action be required, we presently
contemplate that we will seek such approval or take such other action. We are
unable to predict whether we may determine that we are required to delay the
acceptance of options for exchange pending the outcome of any such matter. We
cannot assure you that any such approval or other action, if needed, would be
obtained or would be obtained without substantial conditions or that the
failure to obtain any such approval or other action might not result in adverse
consequences to our business. Our obligation under the Offer to accept
tendered options for exchange and to grant replacement options for tendered
options is subject to conditions, including the conditions described in Section
6 &#150; &#147;Conditions of the Offer.&#148;


<P align="left" style="font-size: 10pt"><B>Section&nbsp;13. CERTAIN FEDERAL INCOME TAX CONSEQUENCES.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The exchange of options pursuant to the Offer should be treated as a
non-taxable exchange and the Company and the Company&#146;s shareholders and
employees should recognize no income for U.S. federal income tax purposes upon
the tender of eligible options and the grant of replacement options. Due to
certain limitations on the extent to which options which become exercisable in
a given calendar year may be treated as incentive stock options, certain
incentive stock options that are tendered in the Offer may be exchanged for
nonqualified stock options. To the extent that this occurs, the Company may be
entitled to a tax deduction upon the exercise of the nonqualified stock options
issued as replacement options which would not have been available to it to the
extent the replacement option was an incentive stock option. In addition, all
replacement options granted to our executive vice president and senior vice
presidents will be nonqualified stock options.


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<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;An optionholder who, due to such limitations, receives nonqualified stock
options in replacement of incentive stock options will, with respect to such
nonqualified stock options, not be eligible for the favorable tax treatment
that is available to incentive stock options. That favorable tax treatment
consists generally of the ability to exercise the option without an immediate
tax liability for the optionee and the ability to receive capital gains tax
treatment upon disposition of the underlying shares under certain
circumstances.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Additional tax information with respect to the replacement options granted
under the 2000 Plan, is provided in the summary plan description in Section&nbsp;8 &#150;
&#147;Source and Amount of Consideration; Terms of Replacement Options &#150; Description
of the Material Terms of the 2000 Plan.&#148; This information is a brief summary
only and reference is made to the Internal Revenue Code of 1986, as amended,
and the regulations and interpretations issued thereunder, for a complete
statement of all relevant federal tax consequences. <B>We recommend that you
consult your own tax advisor with respect to the country, state and local tax
consequences of participating in the Offer.</B>


<P align="left" style="font-size: 10pt"><B>Section&nbsp;14. EXTENSION OF OFFER; TERMINATION; AMENDMENT.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We may, from time to time, extend the period of time during which the
Offer is open and delay accepting any options tendered to us by disseminating
notice of the extension to optionholders by public announcement, oral or
written notice or otherwise as permitted by Rule&nbsp;13e-4(e)(3) under the Exchange
Act, as amended. If the Offer is extended, we will provide appropriate notice
of the extension no later than 9:00 a.m., Eastern Time, on the next business
day following the previously scheduled Expiration Date.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We also expressly reserve the right, in our reasonable judgment, prior to
the Expiration Date, to terminate or amend the Offer and to postpone our
acceptance and cancellation of any options tendered for exchange upon the
occurrence of any of the conditions specified in Section&nbsp;6 &#150; &#147;Conditions of the
Offer,&#148; by disseminating notice of the termination or postponement to the
optionholders by public announcement, oral or written notice or otherwise as
permitted by applicable law. Our reservation of the right to delay our
acceptance and cancellation of options tendered for exchange is limited by Rule
13e-4(f)(5) promulgated under the Exchange Act, as amended, which requires that
we must pay the consideration offered or return the options tendered promptly
after termination or withdrawal of a tender offer.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Subject to compliance with applicable law, we further reserve the right,
in our discretion, and regardless of whether any event set forth in Section&nbsp;6 &#150;
&#147;Conditions of the Offer,&#148; has occurred or is deemed by us to have occurred, to
amend the Offer in any respect, including, without limitation, by decreasing or
increasing the consideration offered in the Offer to optionholders or by
increasing or decreasing the exercise price of options eligible to be tendered
in the Offer. We will notify you of any such amendment and file with the SEC
an amendment to the Schedule&nbsp;TO.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Amendments to the Offer may be made at any time, and from time to time, by
providing appropriate notice of the amendment. Any notice pursuant to the
Offer will be


<P align="center" style="font-size: 10pt">41
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">disseminated promptly to optionholders in a manner reasonably designed to
inform optionholders of such change. We have no obligation to publish,
advertise or otherwise communicate any such public announcement except by
making a press release or as otherwise required or permitted by applicable law.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If we materially change the terms of the Offer or the information
concerning the Offer, or if we waive a material condition of the Offer, we will
extend the Offer to the extent required by Rules&nbsp;13e-4(d)(2) and 13e-4(e)(3)
under the Exchange Act. These rules require that the minimum period during
which a tender or exchange offer must remain open following material changes in
the terms of the offer or information concerning the offer, other than a change
in price or a change in percentage of securities sought, will depend on the
facts and circumstances, including the relative materiality of such terms or
information.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If we decide to take any of the following actions, we will publish notice
or otherwise inform you in writing of such action and keep the Offer open for
at least ten (10)&nbsp;business days after the date of such notification:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(1)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>we increase or decrease the amount of
consideration offered for the eligible options;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(2)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>we decrease the number of options eligible to
be tendered in the Offer; or</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(3)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>we increase the number of options eligible to be tendered in the Offer by an amount that exceeds 2% of the
shares of Common Stock issuable upon exercise of the options that are subject to the Offer immediately prior to the
increase.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt"><B>Section&nbsp;15. FEES AND EXPENSES.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We will not pay any fees or commissions to any broker, dealer or other
person for soliciting tenders of options pursuant to the Offer.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;16. FORWARD-LOOKING STATEMENTS.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Offer to Exchange and the documents incorporated by reference herein
include forward-looking statements. Some of the forward-looking statements can
be identified by the use of forward-looking words including, but not limited
to, &#147;believes,&#148; &#147;expects,&#148; &#147;may,&#148; &#147;will,&#148; &#147;should,&#148; &#147;seeks,&#148; &#147;approximately,&#148;
&#147;intends,&#148; &#147;plans,&#148; &#147;estimates,&#148; or &#147;anticipates&#148; or the negative of those
words or other comparable terminology. Forward-looking statements involve
inherent risks and uncertainties. A number of important factors could cause
actual results to differ materially from those in the forward-looking
statements. These factors include, but are not limited to:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our anticipated business strategies;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our anticipated clinical trials;</TD>
</TR>


</TABLE>

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<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">


<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our ability to conduct clinical trials and our ability to obtain
regulatory approval for product candidates;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our intention to introduce new product candidates;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>our relationships with collaborators;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>anticipated trends in our businesses; and</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">-</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>future capital expenditures.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;You should not place undue reliance on any such forward-looking
statements. Except to the extent required by federal securities laws, we do not
intend to update forward-looking information or to release the results of any
future revisions we may make to forward-looking statements to reflect events or
circumstances after the date hereof or to reflect the occurrence of
unanticipated events.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;17. ADDITIONAL INFORMATION.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We have filed with the SEC a Tender Offer Statement on Schedule&nbsp;TO, of
which this Offer to Exchange is a part, with respect to the Offer. This Offer
to Exchange does not contain all of the information contained in the Schedule
TO and the exhibits to the Schedule&nbsp;TO. We recommend that you review the
Schedule&nbsp;TO, including its exhibits, and the following materials which we have
filed with the SEC, before making a decision on whether to tender your options:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(1)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Our Annual Report on Form 10-K for the year
ended December&nbsp;31, 2003, filed March&nbsp;19, 2004;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(2)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Our Quarterly Reports on Form 10-Q for the
quarters ended March&nbsp;31, 2004, June&nbsp;30, 2004, and September
30, 2004, filed May&nbsp;6, 2004, August&nbsp;5, 2004, and November&nbsp;8,
2004, respectively;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(3)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Our Current Report on Form 8-K filed on
November&nbsp;17, 2004;</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(4)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Our definitive proxy materials for our Special
Meeting of Shareholders to be held on December&nbsp;17, 2004,
filed on November&nbsp;29, 2004; and</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="9%" nowrap align="right">(5)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Our Registration Statement on Form S-8 filed
September&nbsp;24, 2004.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;These filings, our other annual, quarterly and current reports, our proxy
statements and our other Securities and Exchange Commission filings may be
examined at the SEC&#146;s Public Reference Room at 450 Fifth Street, N.W., Room
1024, Washington, D.C. 20549 or on the Internet at http://www.sec.gov.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We will also provide without charge to each person to whom a copy of this
Offer to Exchange is delivered, upon the written or oral request of any such
person, a copy of any or all of the documents to which we have referred above,
other than exhibits to such


<P align="center" style="font-size: 10pt">43
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">documents (unless such exhibits are specifically incorporated by reference
into such documents). Requests should be directed to:



<P align="left" style="margin-left:6%; font-size: 10pt">Regeneron Pharmaceuticals, Inc.<BR>
Attention: Human Resources Department<BR>
777 Old Saw Mill River Road<BR>
Tarrytown, New York 10591


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">As you read the documents listed in this Section&nbsp;17, you may find some
inconsistencies in information from one document to another. Should you find
inconsistencies between the documents, or between a document and this Offer to
Exchange, you should rely on the statements made in the most recent document.
The information contained in this Offer to Exchange about Regeneron should be
read together with the information contained in the documents to which we have
referred you.


<P align="left" style="font-size: 10pt"><B>Section&nbsp;18. MISCELLANEOUS.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We are not aware of any jurisdiction where the making of the Offer is not
in compliance with applicable law. If we become aware of any jurisdiction
where the making of the Offer is not in compliance with any valid applicable
law, we will make a good faith effort to comply with such law. If, after such
good faith effort, we cannot comply with such law, the Offer will not be made
to, nor will tenders be accepted from or on behalf of, the optionholders
residing in such jurisdiction.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>We have not authorized any person to make any recommendation on our behalf
as to whether you should tender or refrain from tendering your options pursuant
to the Offer. You should rely only on the information contained in this
document or to which we have referred you. We have not authorized anyone to
give you any information or to make any representations in connection with the
Offer other than the information and representations contained in this document
or in the related Election Form. If anyone makes any recommendation or
representation to you or gives you any information, you must not rely upon that
recommendation, representation or information as having been authorized by us.</B>


<P align="right" style="font-size: 10pt">Regeneron Pharmaceuticals, Inc.



<P align="left" style="font-size: 10pt">December&nbsp;3, 2004





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<DIV style="font-family: 'Times New Roman',Times,serif">




<P align="center" style="font-size: 10pt">SCHEDULE A



<P align="center" style="font-size: 10pt">INFORMATION CONCERNING THE DIRECTORS AND EXECUTIVE OFFICERS<BR>
OF REGENERON PHARMACEUTICALS, INC.



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The directors and executive officers of Regeneron Pharmaceuticals, Inc.
and their positions and offices as of December&nbsp;3, 2004 are set forth in the
following table:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="27%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="70%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center"><B>Name</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Position and Offices Held</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Charles A. Baker
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Michael S. Brown, M.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Alfred G. Gilman, M.D., Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Murray A. Goldberg
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chief Financial Officer, Senior Vice President, Finance and Administration, Treasurer and
Assistant Secretary (Principal Financial Officer)</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Joseph L. Goldstein, M.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Stuart Kolinski, Esq.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Vice President, General Counsel and Secretary</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">William Roberts, M.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Vice President, Regulatory Development</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Randall G. Rupp, Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Senior Vice President, Manufacturing and Process Sciences</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Arthur F. Ryan
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Leonard S. Schleifer, M.D., Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">President, Chief Executive Officer and Director (Principal Executive Officer)</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Eric M. Shooter, Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">George L. Sing
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Neil Stahl, Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Senior Vice President, Preclinical Development and Biomolecular Science</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">P. Roy Vagelos, M.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chairman of the Board of Directors</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">George D. Yancopoulos, M.D., Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Executive Vice President, Chief Scientific
Officer, President, Regeneron Research Laboratories and Director</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The address of each director and executive officer is: c/o Regeneron
Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591.


<P align="center" style="font-size: 10pt">A-1
</DIV>

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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="center" style="font-size: 10pt"><B>REGENERON PHARMACEUTICALS, INC.</B>



<P align="center" style="font-size: 10pt"><B>OFFER TO EXCHANGE<BR>
OUTSTANDING OPTIONS TO PURCHASE SHARES<BR>
OF COMMON STOCK OF THE REGENERON PHARMACEUTICALS, INC.<BR>
GRANTED UNDER REGENERON PHARMACEUTICALS, INC. 1990 LONG-<BR>
TERM INCENTIVE PLAN AND 2000 LONG-TERM INCENTIVE PLAN<BR>
HAVING AN EXERCISE PRICE PER SHARE OF $18.00 OR MORE<BR>
FOR REPLACEMENT OPTIONS TO BE GRANTED UNDER THE 2000<BR>
LONG-TERM INCENTIVE PLAN</B>

<P align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="30%">


<P align="center" style="font-size: 10pt"><B>THE OFFER AND WITHDRAWAL RIGHTS EXPIRE<BR>
AT 6:00 P.M., EASTERN TIME ON JANUARY 5, 2005,<BR>
UNLESS THE OFFER IS EXTENDED BY REGENERON<BR>PHARMACEUTICALS, INC.</B>


<P align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="30%">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Any questions or requests for assistance or additional copies of any
documents referred to in the Offer to Exchange may be directed to:


<P align="center" style="font-size: 10pt">Regeneron Pharmaceuticals, Inc.<BR>
Attention: Human Resources Department, Option Exchange<BR>
777 Old Saw Mill River Road<BR>
Tarrytown, New York 10591<BR>
(914)&nbsp;345-STOK<BR>
OptionsExchange@regeneron.com


<P align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="30%">

<P align="center" style="font-size: 10pt">December&nbsp;3, 2004




<P align="center" style="font-size: 10pt">
</DIV>

</BODY>
</HTML>

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A.1.II
<SEQUENCE>3
<FILENAME>y69289exv99waw1wii.htm
<DESCRIPTION>EX-99.A.1.II FORM OF ELECTION FORM
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.A.1.II</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="right" style="font-size: 10pt">Exhibit (a)(1)(ii)



<P align="center" style="font-size: 10pt"><B>ELECTION FORM</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I have received the Offer to Exchange dated December&nbsp;3, 2004 (as amended
or supplemented from time to time, the &#147;Offer to Exchange&#148;) relating to the
offer being made by Regeneron Pharmaceuticals, Inc. (the &#147;Company&#148;) to eligible
employees to tender their options to purchase shares of the Company&#146;s common
stock, par value $0.001 per share (the &#147;Common Stock&#148;), having an exercise
price of at least $18.00 per share, granted under the Regeneron
Pharmaceuticals, Inc. 2000 Long-Term Incentive Plan, as amended (the &#147;2000
Plan&#148;), or the Regeneron Pharmaceuticals, Inc. 1990 Long-Term Incentive Plan,
as amended (together with the 2000 Plan, the &#147;Incentive Plans&#148;), in exchange
for replacement options that will be granted under the 2000 Plan (such offer,
upon the terms and conditions set forth in the Offer to Exchange and this
Election Form, being referred as the &#147;Offer&#148;).


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that I am eligible to tender eligible options in the Offer
only if I:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>am a regular Company employee actively employed and working
an average of at least 20 hours a week as of December&nbsp;3, 2004 and on
the Grant Date referred to below; and</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" nowrap align="right">&#149;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>hold at least one eligible option on December&nbsp;3, 2004 and on
the Grant Date.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that I may only tender for exchange in the Offer options that
have an exercise price of at least $18.00 per share that were granted to me
under an Incentive Plan. If I tender any of my eligible options, I must tender
all options under the applicable option grant. This means that I may not
tender for exchange only a portion of an outstanding option grant. However, if
I have previously partially exercised an eligible option grant, I may still
tender for exchange the remaining unexercised portion of such eligible option
grant. I understand that if I have more than one outstanding eligible option
grant, I may tender for exchange all of the options under a grant and choose
not to tender any options subject to a different grant.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that, upon the terms and subject to the conditions of the
Offer, in exchange for those options I validly tender and which are accepted
and cancelled, the Company will grant me replacement options exercisable for
shares of Common Stock, according to the following exchange ratios:

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="80%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="77%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="9%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Exchange Ratio</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Per Share Exercise Price</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>(number of eligible options to be surrendered and</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Range of Eligible Options</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>canceled for each replacement option)</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">$18.00 - $28.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">1.50</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">$28.01 - $37.00</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">2.00</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom" style="background: #eeeeee">
    <TD><DIV style="margin-left:10px; text-indent:-10px">$37.01 and up</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">3.00</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that replacement option grants will be calculated according
to the above exchange ratios and will be rounded down to the nearest whole
share on a grant-by-grant basis. Accordingly, replacement options will not be
granted for fractional shares.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that, upon the terms and subject to the conditions of the
Offer, replacement options will be granted on or as of the date the options I
tender for exchange are accepted and cancelled (the date and time of such grant
of replacement options being referred to as the &#147;Grant Date&#148;), which the
Company expects will be on or as of the Expiration Date (as defined in the
Offer to Exchange and referred to below) or shortly thereafter.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that, in order to remain eligible to receive replacement
options in exchange for options tendered and accepted for exchange pursuant to
the Offer, I must remain an eligible employee as described in the Offer to
Exchange through the Grant Date. I acknowledge that if I am not an eligible
employee on the Grant Date, (including if I die, become disabled, or my
employment terminates for any reason between December&nbsp;3, 2004 and the Grant
Date), then options tendered by me for exchange in the Offer will not be
accepted for exchange and will remain in effect without change. I also
acknowledge, understand and agree that only my eligible options outstanding as
of the Grant Date which I validly tender, and which are accepted for exchange
and cancellation, pursuant to the Offer, will be exchanged for replacement
options.


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that the term of the replacement options I will receive in
exchange for eligible options tendered and accepted for exchange and
cancellation in the Offer may, and the vesting schedule of such replacement
options will, be different than the term and vesting schedule of my tendered
options.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I also understand that the replacement options will be granted under, and
will be subject to the terms and conditions of, the 2000 Plan and the
applicable form of replacement option agreement that will be provided to me
following the Grant Date.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I recognize that, under certain circumstances set forth in the Offer to
Exchange, the Company may terminate or amend the Offer, or postpone its
acceptance and cancellation of any options tendered for exchange. In any such
event, I understand that the options tendered for exchange but not accepted
will remain in effect without change.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand that in order to tender options for exchange in the Offer, I
must sign and complete this Election Form, including marking with an &#147;X&#148; the
applicable box(es) next to the option grant(s) to be tendered for exchange in
the attachment to this Election Form, and timely deliver this completed
Election Form to the Company&#146;s Human Resources Department as specified in the
Instructions to this Election Form. I also understand that if I do not mark
the box(es) under the column entitled &#147;Mark an X to Tender an Option for
Exchange&#148; in the attachment to this Election Form, <B>NONE </B>of the options in the
applicable option grant(s) will be tendered or accepted for exchange and
cancellation in the Offer.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Effective as of the Grant Date, I hereby give up my entire right, title
and interest in and to the options to purchase Common Stock which I have
tendered pursuant to this Election Form and which are accepted by the Company
for exchange and cancellation, pursuant to the Offer. I understand,
acknowledge and agree that all of such options so specified to be tendered
which are accepted by the Company for exchange and cancellation pursuant to the
Offer, and any notices, agreements, certificates or other documentation
evidencing such option(s), will automatically become null and void as of the
Grant Date. I acknowledge that this tender for exchange is entirely voluntary
and that I may withdraw my acceptance of the Offer using the Notice of
Withdrawal that has been provided to me at any time until 6:00 p.m., Eastern
Time, on January&nbsp;5, 2005, the currently scheduled expiration date for the
Offer, or such later expiration date for the Offer if the Company extends the
Offer (such expiration date, as it may be so extended, the &#147;Expiration Date&#148;)<B>.
I also acknowledge that, subject to the terms and conditions of the Offer, this
election will be irrevocable from and after the Expiration Date.</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Upon the terms and subject to the conditions of the Offer, I hereby tender
for exchange and cancellation the eligible options specified (by marking with
an &#147;X&#148; in the box next to each option grant to be tendered) in the attachment
to this Election Form with the heading &#147;Option Grants Eligible for Exchange as
of December&nbsp;1, 2004.&#148; I represent that I have the full power and authority to
tender such options so specified for exchange and cancellation.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="60%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><HR align="left" size="1" noshade width="80%">
Optionholder&#146;s Signature
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR align="left" size="1" noshade width="90%">
Date</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><HR align="left" size="1" noshade width="80%">
Optionholder&#146;s Name<BR>
(please print or type)</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><HR align="left" size="1" noshade width="80%">
Optionholder&#146;s Social Security Number</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<HR align="left" size="1" noshade width="100%">

<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">Instructions if you choose to tender eligible options for exchange in the
Offer:


<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right"><B>1.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Complete and sign this Election Form and send it as soon as possible by
regular or overnight mail to Regeneron Pharmaceuticals, Inc., 777 Old Saw
Mill River Road, Tarrytown, New York 10591, Attention: Human Resources
Department, Options Exchange, or deliver it by hand to Pam Curtis at our
Tarrytown, New York location or Lynne Fuierer at our Rensselaer, New York
location. You should make and keep a copy of the completed and signed
Election Form for your records. <B>This Election Form must be received by
our Human Resources Department as specified above before 6:00 p.m.,
Eastern Time, on January&nbsp;5, 2005, unless the Offer is extended by the
Company, in which case this Election Form must be so received by the
extended expiration date. Your eligible options will not be considered
tendered for exchange unless and until we timely receive a properly
completed and executed copy of this Election Form is timely received by
our Human Resources Department as specified above. </B>We will only accept
delivery of the signed Election Form by hand or regular or overnight mail.
Delivery by e-mail or other electronic means will NOT be accepted. <B>The
method of delivery is at your option and risk. You are responsible for
making sure that this Election Form is timely delivered as specified
above. You must allow for delivery time based on the method of delivery
that you choose to ensure we receive your Election Form on time.</B></TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right">2.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Except as described in the following sentence, this Election Form must be
executed by the optionholder who holds the eligible options to be tendered
for exchange exactly as such optionholder&#146;s name appears on the notice of
grant for such options previously delivered to such optionholder. If the
signature is by an attorney-in-fact or another person acting in a
fiduciary or representative capacity, the signer&#146;s full title and proper
evidence of the authority of such person to act in such capacity must be
identified on this Election Form.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right">3.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>If the optionholder is married and resides in a state the laws of which
provide that a spouse has a community property interest in the eligible
options which the optionholder has elected to tender in the Offer, the
optionholder must timely deliver with this Election Form a Spousal Consent
executed by the optionholder&#146;s spouse, whereby such spouse agrees to be
bound, and agrees that any such community property interest shall
similarly be bound, by this Election Form. Note that New York, New
Jersey, and Connecticut are <B>NOT </B>&#147;community property&#148; states. If you are
uncertain whether the state you reside in is such a &#147;community property&#148;
state, or if you need a Spousal Consent form, please inquire by phone at
914-345-STOK or to our internal e-mail address,
OptionsExchange@regeneron.com, and we will assist you.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="1%" nowrap align="right">4.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>If you do not receive a confirmation of receipt of your Election Form
from the Company via e-mail (or inter-office mail) within five business
days after the date your Election Form should have been received by us, or
if you submitted this Election Form less than five business days before
the date the Offer is scheduled to expire, please contact us by phone at
914-345-STOK or at our internal e-mail address,
OptionsExchange@regeneron.com, to confirm that we have received your
Election Form.</TD>
</TR>




</TABLE>

<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">



</TABLE>


<P align="left" style="font-size: 10pt"><B>Regeneron Pharmaceuticals,
Inc.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; STOCK OPTIONS AND AWARDS CANCELLED</B>



<P align="left" style="font-size: 10pt"><B>Name: &#091;Name of Optionholder&#093;</B>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" align="center"><B>ID &#091;Social</B></TD>

    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Grant</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Cancel</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Name</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Security No.&#093;</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Number</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Date</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Plan</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Date</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Cancel Reason</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Shares</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Price</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" colspan="3"><B>Total Price</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&#091;&nbsp;&nbsp;&#093;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&#091;&nbsp;&nbsp;&#093;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right"><HR size="1" noshade>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>Hi</TD>
    <TD align="right">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left"></TD>
    <TD align="center">&#091;&nbsp;&nbsp;&#093;</TD>
    <TD align="center"></TD>

</TR>
<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>Avg</TD>
    <TD>&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left"></TD>
    <TD align="center"></TD>
    <TD align="center"></TD>

</TR>

<TR valign="bottom">
    <TD><DIV style="margin-left:10px; text-indent:-10px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>Low</TD>
    <TD>&#091;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left"></TD>
    <TD align="center"></TD>
    <TD align="center"></TD>

</TR>
<!-- End Table Body -->
</TABLE>
</DIV>




<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

</BODY>
</HTML>

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A.1.III
<SEQUENCE>4
<FILENAME>y69289exv99waw1wiii.htm
<DESCRIPTION>EX-99.A.1.III FORM OF NOTICE OF WITHDRAWAL
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.A.1.III</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="right" style="font-size: 10pt">Exhibit (a)(1)(iii)



<P align="center" style="font-size: 10pt"><B>NOTICE OF WITHDRAWAL</B>


<HR align="left" size="1" noshade width="100%">

<P align="left" style="margin-left: 0%; text-indent: 0%; margin-right: 0%; font-size: 10pt">If you previously submitted an Election Form to tender for exchange and
cancellation some or all of your eligible options, pursuant to the Offer to
Exchange dated December&nbsp;3, 2004 (as amended or supplemented from time to time,
the &#147;Offer to Exchange&#148; which, together with the Election Form accompanying the
Offer to Exchange, constitutes the &#147;Offer&#148;), and you wish to withdraw your
tender of some or all of such options, you must execute this Notice of
Withdrawal and send it as soon as possible by regular or overnight mail to
Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New
York 10591, Attn: Human Resources Department, Options Exchange, or deliver it
by hand to Pam Curtis at our Tarrytown, New York location or Lynne Fuierer at
our Rensselaer, New York location. Your eligible options tendered for exchange
will not be considered withdrawn unless a properly completed and signed Notice
of Withdrawal is received by our Human Resources Department as specified above
before 6:00 p.m., Eastern Time, on January&nbsp;5, 2005, or such later expiration
date of the Offer if the Company extends the Offer. If you miss this deadline
but remain an eligible optionholder as described in the Offer to Exchange, any
eligible options previously validly tendered by you and accepted for exchange
will be cancelled and exchanged pursuant to the Offer. We will only accept
delivery of the signed Notice of Withdrawal by hand or regular or overnight
mail as specified above. Delivery by e-mail or other electronic means will NOT
be accepted<B>. The method of delivery is at your option and risk. You are
responsible for making sure that the Notice of Withdrawal is timely delivered
as specified above. You must allow for delivery time based on the method of
delivery that you choose to ensure we receive your Notice of Withdrawal on
time.</B>

<p><HR align="left" size="1" noshade width="100%">

<P align="left" style="font-size: 10pt">To Regeneron Pharmaceuticals, Inc.:



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I previously received a copy of the Offer to Exchange dated December&nbsp;3,
2004 and the related Election Form. I signed and returned the Election Form,
whereby I tendered for exchange certain options pursuant to the Offer to
Exchange. I now wish to withdraw my tender with respect to the stock option
grant(s) specified below<B>. I understand that by withdrawing my tender with
respect to the stock option grant(s) specified below, I am withdrawing my
tender of all the options covered by such specified grant(s).</B>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I understand and acknowledge that, by withdrawing my previously tendered
options specified below, I will not be granted any replacement options in
exchange for such previously tendered options and I will retain such options
with their existing exercise price(s), term(s) vesting schedule(s) and other
terms and conditions. I also understand and acknowledge that all of such
options will continue to be governed by the Long-Term Incentive Plan under
which they were granted and the form(s) of option agreement(s) previously
provided to me in connection with the grant of such options.

<HR align="left" size="1" noshade width="100%">

<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I hereby withdraw all of the eligible options subject to the option
grant(s) listed below which I previously tendered for exchange and cancellation
pursuant to the Offer. I have therefore completed this Notice of Withdrawal in
accordance with the withdrawal instructions on the next page and have signed
exactly as my name appears on the Notice of Grant for such options previously
delivered to me.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="60%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><HR align="left" size="1" noshade width="80%">
Optionholder&#146;s Signature
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR align="left" size="1" noshade width="80%">
Date</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><HR align="left" size="1" noshade width="80%">
Optionholder&#146;s Name</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><HR align="left" size="1" noshade width="80%">
Social Security Number</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">Options Withdrawn:


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="32%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Grant Number</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Grant Date</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Expiration Date</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Exercise Price</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Option Shares Granted</B><HR size="1" noshade></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
    <TD valign="top"><HR size="1" noshade><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><HR size="1" noshade><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><HR size="1" noshade><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><HR size="1" noshade><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;

</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
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</DIV></TD>
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</TD>
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</TD>
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</TD>
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</TR>
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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
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</DIV></TD>
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</TD>
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</TD>
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</TD>
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</TR>
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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
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</TR>
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</DIV></TD>
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</TD>
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</TD>
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</TD>
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</TR>
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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
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</TR>
<TR style="font-size: 1px">
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</DIV></TD>
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</TD>
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</TD>
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</TD>
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</TR>
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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
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    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><HR size="1" noshade><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><HR size="1" noshade><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">2
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="left" style="font-size: 10pt">Withdrawal Instructions:



<P>
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right"><B>1.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Complete and sign this Notice of Withdrawal and send it as soon as
possible by regular or overnight mail to Regeneron Pharmaceuticals,
Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591,
Attention: Human Resources Department, Options Exchange, or deliver it
by hand to Pam Curtis at our Tarrytown, New York location or Lynne
Fuierer at our Rensselaer, New York location. You should make and keep
a copy of the completed and signed Notice of Withdrawal for your
records. <B>This Notice of Withdrawal must be received by our Human
Resources Department as specified above before 6:00 p.m., Eastern Time,
on January&nbsp;5, 2005, unless the Offer is extended by Regeneron
Pharmaceuticals, Inc., in which case this Notice of Withdrawal must be
so received by the extended expiration date. Your tendered options
will not be considered withdrawn unless and until a properly completed
and executed copy of this Notice of Withdrawal is timely received by
our Human Resources Department as specified above. </B>We will only accept
delivery of the signed Notice of Withdrawal by hand or regular or
overnight mail. Delivery by e-mail or other electronic means will NOT
be accepted. <B>The method of delivery is at your option and risk. You
are responsible for making sure that this Notice of Withdrawal is
timely delivered as specified above. You must allow for delivery time
based on the method of delivery that you choose to ensure we receive
your Notice of Withdrawal on time.</B></TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">2.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Except as described in the following sentence, this Notice of
Withdrawal must be executed by the eligible optionholder who holds the
eligible options to be tendered for exchange exactly as such
optionholder&#146;s name appears on the notice of grant for such options
previously delivered to such optionholder. If the signature is by an
attorney-in-fact or another person acting in a fiduciary or
representative capacity, the signer&#146;s full title and proper evidence of
the authority of such person to act in such capacity must be identified
on this Notice of Withdrawal.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">3.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>If the optionholder is married and resides in a state the laws of
which provide that a spouse has a community property interest in the
eligible options the tender of which is being withdrawn pursuant to
this Notice of Withdrawal, the optionholder must timely deliver with
this Notice of Withdrawal a Spousal Consent form executed by the
optionholder&#146;s spouse, whereby such spouse agrees to be bound, and
agrees that any such community property interest shall similarly be
bound, by this Notice of Withdrawal. Note that New York, New Jersey,
and Connecticut are <B>NOT </B>&#147;community property&#148; states. If you are
uncertain whether the state you reside in is such a &#147;community
property&#148; state, or if you need a Spousal Consent form, please inquire
by phone at 914-345-STOK or to our internal e-mail address,
OptionsExchange@regeneron.com, and we will assist you.</TD>
</TR>

<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="right">4.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>If you do not receive a confirmation of receipt of your Notice of
Withdrawal from us via e-mail (or inter-office mail) within five
business days after the date your Notice of Withdrawal should have been
received by us, or if you submit your Notice of Withdrawal less than
five business days before the date the Offer is scheduled to expire,
please contact us by phone at 914-345-STOK or at our internal e-mail
address, OptionsExchange@regeneron.com, to confirm that we have
received your Notice of Withdrawal.</TD>
</TR>

</TABLE>



<P align="center" style="font-size: 10pt">3
</DIV>

</BODY>
</HTML>

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A.1.IV
<SEQUENCE>5
<FILENAME>y69289exv99waw1wiv.htm
<DESCRIPTION>EX-99.A.1.IV FORM OF ACCEPTANCE LETTER
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.A.1.IV</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="right" style="font-size: 10pt">EXHIBIT(a)(1)(iv)


<P align="center" style="font-size: 10pt"><B>FORM OF ACCEPTANCE LETTER</B>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">

<!-- Begin Table Head --><TR valign="bottom">
    <TD width="8%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>

<!-- End Table Head -->

<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">To:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name of Tendering Regeneron Pharmaceuticals, Inc. Optionholder</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">From:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Date:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;, 2005</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Re:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Acceptance and Cancellation of Tendered Options</TD>
</TR>


<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Thank you for your participation in the Regeneron Pharmaceuticals, Inc.
Option Exchange Program. As you may know, on &#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;, 2005 we accepted
eligible options that were validly tendered pursuant to the Offer to Exchange
dated December&nbsp;3, 2004 (as it may have been amended or supplemented from time
to time) and the related Election Form (which together constituted the
&#147;Offer&#148;). We confirm with this letter that we have accepted your tender for
exchange the options identified in the signed Election Form(s) you submitted
and have cancelled the options you tendered for exchange and cancellation as
set forth in the attachment entitled &#147;Stock Options and Awards Cancelled.&#148;


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In accordance with the Offer, as of &#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;, 2005, we granted to
you replacement options as identified in the attached Replacement Option
Agreement(s) and Notice of Grant of Replacement Options. The replacement
options have been granted under our 2000 Long-Term Incentive Plan and are
subject to the terms and conditions of that Plan and the applicable form of
option agreement, each of which is enclosed herewith.

<P align="left" style="font-size: 10pt">Neither participation in the Option Exchange Program, this Acceptance Letter,
nor the attached Replacement Option Agreement(s) and Notice of Grant of
Replacement Options confers upon you the right to remain an employee of
Regeneron Pharmaceuticals, Inc. The terms of your employment with us remain
unchanged.


<P align="left" style="font-size: 10pt">If you have questions regarding the foregoing, please contact our Human
Resources Department by phone at 914-345-STOK or send your question to our
internal e-mail address, OptionsExchange@regeneron.com or by interoffice mail.



<P align="left" style="font-size: 10pt; margin-left: 50%">Regeneron Pharmaceuticals, Inc.


<P align="left" style="font-size: 10pt; margin-left: 50%">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;<BR>
&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="left" style="font-size: 10pt"><B>Regeneron Pharmaceuticals, Inc.</B>


<P align="center" style="font-size: 10pt"><B>STOCK OPTIONS AND AWARDS CANCELLED</B>



<P align="left" style="font-size: 10pt"><B>Name: &#091;Name of Optionholder&#093;</B>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">

<!-- Begin Table Head --><TR valign="bottom">
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>ID &#091;Social</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Grant</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Cancel</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>&nbsp;</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>&nbsp;</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Name</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Security No.&#093;</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Number</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Date</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Plan</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Date</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Cancel Reason</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Shares</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Price</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Total Price</B><HR size="1" noshade></TD>
</TR>


<!-- End Table Head -->

<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;</TD>
</TR>

<TR valign="bottom">
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;</TD>
</TR>

<TR style="font-size: 1px">
    <TD align="center" valign="top">
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><HR size="1" noshade>&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">Hi&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">Avg&nbsp;&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD align="center" valign="top">
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">Low&nbsp;&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>


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</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

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</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A.1.V
<SEQUENCE>6
<FILENAME>y69289exv99waw1wv.htm
<DESCRIPTION>EX-99.A.1.V FORM OF COMMUNICATION
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.A.1.V</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<P align="right" style="font-size: 10pt">EXHIBIT (a)(1)(v)


<P align="center" style="font-size: 10pt"><B>FORM OF COMMUNICATION TO<BR>
REGENERON PHARMACEUTICALS, INC. OPTIONHOLDERS CONFIRMING RECEIPT OF<BR>
ELECTION FORM/NOTICE OF WITHDRAWAL</B>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">

<!-- Begin Table Head --><TR valign="bottom">
    <TD width="8%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="87%">&nbsp;</TD>
</TR>

<!-- End Table Head -->

<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">To:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;Name of Optionholder&#093;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">From:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Regeneron Pharmaceuticals, Inc.</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Date:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;, 2005</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Re:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Confirmation of Receipt of &#091;Election Form&nbsp;OR Notice of Withdrawal&#093;</TD>
</TR>


<!-- End Table Body -->
</TABLE>
</DIV>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This message confirms that we have received your &#091;Election Form&nbsp;OR Notice
of Withdrawal&#093; in connection with our offer being made to eligible employees to
tender options to purchase our Common Stock, upon the terms and conditions set
forth in the Offer to Exchange dated December&nbsp;3, 2004 (as amended or
supplemented from time to time, the &#147;Offer to Exchange&#148;) and the related
Election Form (which together constitute the &#147;Offer&#148;). The Offer will expire
at 6:00 p.m. Eastern Time, on January&nbsp;5, 2005, unless the Offer is extended in
accordance with the Offer to Exchange.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If you have any questions, please contact us by phone to 914-345-STOK or
to our internal e-mail address, OptionsExchange@Regeneron.com. or by
interoffice mail.



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>


</BODY>
</HTML>

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.D.7
<SEQUENCE>7
<FILENAME>y69289exv99wdw7.htm
<DESCRIPTION>EX-99.D.7 FORM OF REPLACEMENT OPTION AGREEMENT AND NOTICE OF GRANT OF REPLACEMENT OPTIONS
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.D.7</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="right" style="font-size: 10pt">EXHIBIT(d)(7)


<P align="center" style="font-size: 10pt"><B>Form of Replacement Option Agreement<BR>
and Notice of Grant of Replacement Options for Employees<BR>
of Regeneron Pharmaceuticals, Inc. other than Vice Presidents.</B>


<HR size="2" noshade width="100%">


<P align="left" style="font-size: 10pt; margin-left: 50%"><B>Regeneron Pharmaceuticals, Inc.<BR>
ID: </B>&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;

<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="65%">

<!-- Begin Table Head --><TR valign="bottom">
    <TD width="59%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="36%">&nbsp;</TD>
</TR>

<!-- End Table Head -->

<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>Notice of Grant of Stock Options</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">777 Old Saw Mill River Road</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>and Option Agreement for Replacement</B><BR>
<B>Option Awards</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Tarrytown, New York 10591</TD>
</TR>


<!-- End Table Body -->
</TABLE>
</DIV>


<HR size="2" noshade width="100%">



<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="55%">

<!-- Begin Table Head --><TR valign="bottom">
    <TD width="50%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="33%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
</TR>

<!-- End Table Head -->

<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>&#091;OPTIONEE NAME&#093;</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Option Number:</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap colspan="3" align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>&#091;OPTIONEE ADDRESS&#093;</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Plan:</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top"><B>2004</B></TD>
    <TD nowrap valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>ID</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap colspan="3" align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
</TR>


<!-- End Table Body -->
</TABLE>
</DIV>

<HR size="2" noshade width="100%">



<P align="left" style="font-size: 10pt">Effective &#060;date&#062; (the &#147;Grant Date&#148;) you have been granted a(n)
&#091;Incentive&#093;&#091;Non-Qualified&#093; Stock Option to buy &#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093; shares of
Regeneron Pharmaceuticals, Inc. (the Company) stock at &#091;$&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093; per share.


<P align="left" style="font-size: 10pt">The total option price of the shares granted is &#091;$&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;.


<P align="left" style="font-size: 10pt">Shares in each period will become fully vested on the date shown.


<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="55%">

<!-- Begin Table Head --><TR valign="bottom">
    <TD width="8%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="33%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="37%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="7%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Shares</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Vest Type</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Full Vest</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Expiration Date</B><HR size="1" noshade></TD>
</TR>


<!-- End Table Head -->

<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/06&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/07&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/08&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/09&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>


<!-- End Table Body -->
</TABLE>
</DIV>

<HR size="2" noshade width="100%">



<P align="left" style="font-size: 10pt">You and the Company agree that these options are granted under and governed by
the terms and conditions of the Company&#146;s 2000 Long-Term Incentive Plan as
amended and the enclosed Option Agreement, both of which are attached and made
a part of this document.

<P>
<HR size="2" noshade width="100%">



<P>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="left">*</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Option vests in approximately equal annual 25% installments</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="left">**</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Full Vest Dates will occur on the first, second, third and fourth
anniversaries of the Grant Date</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right">***</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Option expires at the later to occur of (i)&nbsp;remaining term of the
tendered option it replaces and (ii)&nbsp;6&nbsp;years from Grant Date</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">1
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">






<P align="center" style="font-size: 10pt"><B>REGENERON PHARMACEUTICALS, INC.<BR>
OPTION AGREEMENT PURSUANT TO THE<BR>
2000 LONG-TERM INCENTIVE PLAN</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;THIS AGREEMENT, made as of the date on the <I>Notice of Grant of Stock
Options</I>, by and between Regeneron Pharmaceuticals, Inc., a New York corporation
(the &#147;Company&#148;), and the employee named on the <I>Notice of Grant of Stock Options</I>
(the &#147;Grantee&#148;);


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;WHEREAS, the Grantee is an employee of the Company and the Company desires
to afford the Grantee the opportunity to acquire or enlarge the Grantee&#146;s stock
ownership in the Company so that the Grantee may have a direct proprietary
interest in the Company&#146;s success; and


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;WHEREAS, the Committee administering the 2000 Long-Term Incentive Plan
(the &#147;Plan&#148;) has granted (as of the effective date of grant specified in the
<I>Notice of Grant of Stock Options</I>) to the Grantee a Stock Option to purchase the
number of shares of the Company&#146;s Common Stock ($.001 par value) (the &#147;Common
Stock&#148;) as set forth in the <I>Notice of Grant of Stock Options</I>.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOW, THEREFORE, in consideration of the covenants and agreements herein
contained, the parties agree as follows:


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>1.&nbsp;Grant of Award. </B>Pursuant to Section&nbsp;7 of the Plan, the Company grants
to the Grantee, subject to the terms and conditions of the Plan and subject
further to the terms and conditions set forth here, the option to purchase from
the Company all or any part of an aggregate of shares of Common Stock at the
purchase price per share (the &#147;Option&#148;) as shown on the <I>Notice of Grant of
Stock Options</I>. &#091;The Option is intended to be an Incentive Stock Option under
Section&nbsp;422 of the Internal Revenue Code of 1986, as amended (the &#147;Code&#148;).
Notwithstanding the foregoing, the Option will not qualify as an Incentive
Stock Option, among other events, (i)&nbsp;if the Grantee disposes of the Common
Stock acquired pursuant to the Option at any time during the two year period
following the date of this Agreement or the one year period following the date
on which the Option is exercised, or (ii)&nbsp;if the Grantee is not employed by the
Company or a subsidiary of the Company within the meaning of Section&nbsp;424 of the
Code (a &#147;Subsidiary&#148;) at all times during the period beginning on the date of
this Agreement and ending on the day three months before the date of exercise
of the Option, or (iii)&nbsp;to the extent the aggregate fair market value
(determined as of the time the Option is granted) of the stock subject to
Incentive Stock Options which become exercisable for the first time in any
calendar year exceeds $100,000. To the extent that the Option does not qualify
as an Incentive Stock Option, it shall constitute a separate Non-Qualified
Stock Option.&#093;<SUP>1</SUP> &#091;No part of the Option granted hereby is intended to qualify
as an Incentive Stock Option under Section&nbsp;422 of the Internal Revenue Code of
1986, as amended (the &#147;Code&#148;).&#093;<SUP>2</SUP>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>2.&nbsp;Vesting. </B>(a)&nbsp;The Option is exercisable in installments as provided on
the <I>Notice of Grant of Stock Options</I>. To the extent that the Option has become
exercisable with respect to the number of shares of Common Stock as provided on
the <I>Notice of Grant of Stock Options </I>and subject to the terms and conditions of
the Plan, including without limitation, Section&nbsp;7(c)(1) &#038; (2), the Option may
thereafter be exercised by the Grantee, in whole or in part, at any time or
from time to time prior to the expiration of the Option in accordance with the
requirements set forth in Section&nbsp;7(c)(3) of the Plan, including, without
limitation, the filing of such written form of exercise notice as may be
promulgated by the Committee, and in accordance with applicable tax and other
laws. The Company shall have the right to require the Grantee in connection
with the exercise of the Option to remit to the Company in cash an amount
sufficient to satisfy any federal, state and local withholding tax requirements
related thereto.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;The <I>Notice of Grant of Stock Options </I>indicates each date upon which
the Grantee shall be entitled to exercise the Option with respect to the
additional number of shares of Common Stock granted as indicated provided that
the Grantee has not incurred a termination of employment or service with the
Company and all Subsidiaries (collectively, the Company and all Subsidiaries
shall be referred to herein as the &#147;Employer&#148; and no termination of employment
or service shall be deemed to take place unless the Grantee is no longer
employed by or providing service to the Employer) prior to such date. There
shall be no proportionate or partial vesting in the periods between the Full
Vest Dates specified in the <I>Notice of Grant of Stock Options </I>and all vesting
shall occur only on the Full Vest Dates. Except as otherwise provided in any
employment agreement, consulting agreement, change in control agreement or
similar agreement in effect between the Employer and the Grantee on the date
specified in the Notice of Grant of Stock Options, no vesting shall occur after
such date as the Grantee ceases to be employed by the Employer and all unvested
Options shall be forfeited at such time.



<P>

<HR size="1" width="18%" align="left" noshade>


<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>1</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">This text will appear in agreements for Replacement Options that are intended
to be incentive stock options under Section&nbsp;422 of the Internal Revenue Code of
1986, as amended.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>2</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">This text will appear in agreements for Replacement Options that are not
intended to be incentive stock options under Section&nbsp;422 of the Internal
Revenue Code of 1986, as amended.</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">2
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">






<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Notwithstanding anything herein (except the following sentence) or in
the <I>Notice of Grant of Stock Options </I>to the contrary, the Option shall be fully
vested if the Grantee&#146;s employment with the Employer is terminated on or within
two years after the occurrence of a Change in Control by the Employer (other
than for Cause). Except as otherwise provided in any employment agreement,
consulting agreement, change in control agreement or similar agreement in
effect between the Employer and the Grantee on the date of grant specified in
the <I>Notice of Grant of Stock Options</I>, if the application of the provision in
the preceding sentence, any similar provisions in other stock option or
restricted stock grants, and other payments and benefits payable to Grantee
upon termination of employment with the Company (collectively, the &#147;Company
Payments&#148;) would result in the Grantee being subject to excise tax under
Internal Revenue Code Section&nbsp;4999 (the &#147;Excise Tax&#148;), the amount of any
Company Payments shall be automatically reduced to an amount one dollar less
than an amount that would subject the Grantee to the Excise Tax; provided,
however, that the reduction shall occur only if the reduced Company Payments
received by the Grantee (after taking into account further reductions for
applicable federal, state and local income, social security and other taxes)
would be greater than the unreduced Company Payments to be received by the
Grantee minus (i)&nbsp;the Excise Tax payable with respect to such Company Payments
and (ii)&nbsp;all applicable federal, state and local income, social security and
other taxes on such Company Payments. If the Company Payments are to be
reduced in accordance with the foregoing, the Company Payments shall be reduced
as mutually agreed between the Employer and the Grantee or, in the event the
parties cannot agree, in the following order (1)&nbsp;acceleration of vesting of any
option where the exercise price exceeds the fair market value of the underlying
shares at the time the acceleration would otherwise occur, (2)&nbsp;any lump sum
severance based on a multiple of base salary or bonus, (3)&nbsp;any other cash
amounts payable to the Grantee, (4)&nbsp;any benefits valued as parachute payments,
and (5)&nbsp;acceleration of vesting of any equity not covered by (1)&nbsp;above.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>3.&nbsp;Option Term. </B>(a)&nbsp;Except as otherwise provided in the next sentence or
in the Plan, the Option shall expire on Expiration Date shown on the <I>Notice of
Grant of Stock Options</I>. In the event of termination of employment or service
with the Employer, the vested portion of the Option shall expire on the earlier
of (i)&nbsp;the Expiration Date, or (ii) (A)&nbsp;three months after such termination if
such termination is for any reason other than death, retirement, or long-term
disability, (B)&nbsp;two years after such termination if such termination is due to
the Grantee&#146;s retirement, (C)&nbsp;one year after the termination if such
termination is due to the Grantee&#146;s death or long-term disability, or (D)&nbsp;the
occurrence of the Cause event if such termination is for Cause or Cause existed
at the time of such termination (whether then known or later discovered).


<P>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" style="background: transparent">&nbsp;</TD>
    <TD width="1%" nowrap align="right">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>For purposes of this Agreement, &#147;Cause&#148; shall mean (i)&nbsp;in the
case where there is no employment agreement, consulting agreement,
change in control agreement or similar agreement in effect between
the Company and the Grantee on the date of grant specified in the
Notice of Grant of Stock Options (or where there is such an agreement
but it does not define &#147;cause&#148; (or words of like import)) (A)&nbsp;the
willful and continued failure by the Grantee substantially to perform
his or her duties and obligations to the Employer, including without
limitation, repeated refusal to follow the reasonable directions of
the Employer, knowing violation of law in the course of performance
of the duties of the Grantee&#146;s employment with the Employer, repeated
absences from work without a reasonable excuse, and intoxication with
alcohol or illegal drugs while on the Employer&#146;s premises during
regular business hours (other than any such failure resulting from
his or her incapacity due to physical or mental illness); (B)&nbsp;fraud
or material dishonesty against the Employer; or (C)&nbsp;a conviction or
plea of guilty or nolo contendere to a felony or a crime involving
material dishonesty or (ii)&nbsp;in the case where there is an employment
agreement, consulting agreement, change in control agreement or
similar agreement in effect between the Employer and the Grantee on
the date of grant specified in the Notice of Grant of Stock Options
that defines &#147;cause&#148; (or words of like import), as defined under such
agreement. For purposes of this Section&nbsp;3(b), no act, or failure to
act, on a Grantee&#146;s part shall be considered &#147;willful&#148; unless done,
or omitted to be done, by the Grantee in bad faith and without
reasonable belief that his or her action or omission was in the best
interest of the Employer. Any determination of Cause made prior to a
Change in Control shall be made by the Committee in its sole
discretion.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>4.&nbsp;Restrictions on Transfer of Option. </B>The Option granted hereby shall
not be transferable other than by will or by the laws of descent and
distribution. During the lifetime of the Grantee, this Option shall be
exercisable only by the Grantee. In addition, except as otherwise provided in
this Agreement, the Option shall not be assigned, negotiated, pledged or
hypothecated in any way (whether by operation of law or otherwise), and the
Option shall not be subject to execution, attachment or similar process. Upon
any other attempt to transfer, assign, negotiate, pledge or hypothecate the
Option, or in the event of any levy upon the option by reason of any execution,
attachment, or similar process contrary to the provisions hereof, the Option
shall immediately become null and void. Notwithstanding the foregoing
provisions of this Section&nbsp;4, subject to the approval of the Committee in its
sole and absolute discretion and to any conditions that the Committee may
prescribe, the Grantee may, upon providing written notice to the Company, elect
to transfer the Option to members of his or her immediate family, including,
but not limited to, children, grandchildren and spouse or to trusts for the
benefit of such immediate family members or to partnerships in which such
family members are the only partners; provided, however, that no such transfer
may be made in exchange for consideration.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>5.&nbsp;Rights of a Stockholder. </B>The Grantee shall have no rights as a
stockholder with respect to any shares of Common Stock subject to this Option
prior to the date of issuance to the Grantee of a certificate or certificates
for such shares.


<P align="center" style="font-size: 10pt">3
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">
<P align="left" style="font-size: 10pt">No adjustment shall be made for dividends in cash or other property,
distributions, or other rights with respect to such shares for which the record
date is prior to the date upon which the Grantee shall become the holder of
record therefor.



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>6.&nbsp;Compliance with Law and Regulations. </B>This award and any obligation of
the Company hereunder shall be subject to all applicable federal, state and
local laws, rules and regulations and to such approvals by any government or
regulatory agency as may be required. The Company shall be under no obligation
to effect the registration pursuant to federal securities laws of any interests
in the Plan or any shares of Common Stock to be issued hereunder or to effect
similar compliance under any state laws. The Company shall not be obligated to
cause to be issued or delivered any certificates evidencing shares of Common
Stock pursuant to this Agreement unless and until the Company is advised by its
counsel that the issuance and delivery of such certificates is in compliance
with all applicable laws, regulations of governmental authority and the
requirements of any securities exchange on which shares of Common Stock are
traded. The Committee may require, as a condition of the issuance and delivery
of certificates evidencing shares of Common Stock pursuant to the terms hereof,
that the recipient of such shares make such agreements and representations, and
that such certificates bear such legends, as the Committee, in its sole
discretion, deems necessary or desirable. Except to the extent preempted by
any applicable federal law, this Agreement shall be construed and administered
in accordance with the laws of the State of New York without reference to its
principles of conflicts of law.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>7.&nbsp;Grantee Bound by Plan. </B>The Grantee acknowledges receipt of a copy of
the Plan and agrees to be bound by all the terms and provisions thereof. The
Plan is incorporated herein by reference, and any capitalized term used but not
defined herein shall have the same meaning as in the Plan. To the extent that
this Agreement is silent with respect to, or in any way inconsistent with, the
terms of the Plan, the provisions of the Plan shall govern and this Agreement
shall be deemed to be modified accordingly.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>8.&nbsp;Notices. </B>Any notice or communication given hereunder shall be in
writing and shall be deemed given when delivered in person, or by United States
mail, at the following addresses: (i)&nbsp;if to the Employer, to: Regeneron
Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591,
Attention: Secretary, and (ii)&nbsp;if to the Grantee, to: the Grantee at
Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY
10591, or, if the Grantee has terminated employment, to the last address for
the Grantee indicated in the records of the Employer, or such other address as
the relevant party shall specify at any time hereafter in accordance with this
Section&nbsp;8.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>9.&nbsp;No Obligation to Continue Employment. </B>This Agreement does not
guarantee that the Employer will employ the Grantee for any specified time
period, nor does it modify in any respect the Grantee&#146;s employment or
compensation.



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<DOCUMENT>
<TYPE>EX-99.D.8
<SEQUENCE>8
<FILENAME>y69289exv99wdw8.htm
<DESCRIPTION>EX-99.D.8 FORM OF REPLACMENT OPTION AGREEMENT AND NOTICE OF GRANT OF REPLACEMENT OPTIONS
<TEXT>
<HTML>
<HEAD>
<TITLE>EXHIBIT 99.D.8</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="right" style="font-size: 10pt">EXHIBIT(d)(8)


<P align="center" style="font-size: 10pt"><B>Form of Replacement Option Agreement and<BR>
Notice of Grant of Replacement Options for Vice Presidents<BR>
of Regeneron Pharmaceuticals, Inc.</B>

<HR size="2" noshade width="100%">


<P align="left" style="font-size: 10pt; margin-left: 50%"><B>Regeneron Pharmaceuticals, Inc.<BR>
ID: </B>&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;

<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="65%">

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</TR>

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<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>Notice of Grant of Stock Options</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">777 Old Saw Mill River Road</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>and Option Agreement for Replacement</B><BR><B>Option Awards</B>

</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Tarrytown, New York 10591</TD>
</TR>


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</TABLE>
</DIV>


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<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="55%">

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    <TD width="33%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
</TR>

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<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>&#091;OPTIONEE NAME&#093;</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Option Number:</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap colspan="3" align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>&#091;OPTIONEE ADDRESS&#093;</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Plan:</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top"><B>2004</B></TD>
    <TD nowrap valign="top">&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>ID</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap colspan="3" align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
</TR>


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</TABLE>
</DIV>

<HR size="2" noshade width="100%">


<P align="left" style="font-size: 10pt">Effective &#060;date&#062; (the &#147;Grant Date&#148;) you have been granted a(n)
&#091;Incentive&#093;&#091;Non-Qualified&#093; Stock Option to buy &#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093; shares of
Regeneron Pharmaceuticals, Inc. (the Company) stock at &#091;$&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093; per share.


<P align="left" style="font-size: 10pt">The total option price of the shares granted is &#091;$ &#093;.


<P align="left" style="font-size: 10pt">Shares in each period will become fully vested on the date shown.


<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="55%">

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    <TD width="33%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="37%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="7%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Shares</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Vest Type</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Full Vest</B><HR size="1" noshade></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Expiration Date</B><HR size="1" noshade></TD>
</TR>


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<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/06&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/07&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/08&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">On Vest Date
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#091;1/_/09&#093;**
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">***</TD>
</TR>


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</TABLE>
</DIV>

<HR size="2" noshade width="100%">


<P align="left" style="font-size: 10pt">You and the Company agree that these options are granted under and governed by
the terms and conditions of the Company&#146;s 2000 Long-Term Incentive Plan as
amended and the enclosed Option Agreement, both of which are attached and made
a part of this document.

<P>
<HR size="2" noshade width="100%">



<P>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="left">*</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Option vests in approximately equal annual 25% installments</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="left">**</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Full Vest Dates will occur on the first, second, third and fourth
anniversaries of the Grant Date</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right">***</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Option expires at the later to occur of (i)&nbsp;remaining term of the
tendered option it replaces and (ii)&nbsp;6&nbsp;years from Grant Date</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">1
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">






<P align="center" style="font-size: 10pt"><B>REGENERON PHARMACEUTICALS, INC.</B>



<P align="center" style="font-size: 10pt"><B>OPTION AGREEMENT<BR>
PURSUANT TO THE<BR>
2000 LONG-TERM INCENTIVE PLAN</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;THIS AGREEMENT, made as of the date on the <I>Notice of Grant of Stock
Options</I>, by and between Regeneron Pharmaceuticals, Inc., a New York corporation
(the &#147;Company&#148;), and the employee named on the <I>Notice of Grant of Stock Options</I>
(the &#147;Grantee&#148;);


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;WHEREAS, the Grantee is an employee of the Company and the Company desires
to afford the Grantee the opportunity to acquire or enlarge the Grantee&#146;s stock
ownership in the Company so that the Grantee may have a direct proprietary
interest in the Company&#146;s success; and


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;WHEREAS, the Committee administering the 2000 Long-Term Incentive Plan
(the &#147;Plan&#148;) has granted (as of the effective date of grant specified in the
<I>Notice of Grant of Stock Options</I>) to the Grantee a Stock Option to purchase the
number of shares of the Company&#146;s Common Stock ($.001 par value) (the &#147;Common
Stock&#148;) as set forth in the <I>Notice of Grant of Stock Options</I>.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOW, THEREFORE, in consideration of the covenants and agreements herein
contained, the parties agree as follows:


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>1.&nbsp;Grant of Award. </B>Pursuant to Section&nbsp;7 of the Plan, the Company grants
to the Grantee, subject to the terms and conditions of the Plan and subject
further to the terms and conditions set forth here, the option to purchase from
the Company all or any part of an aggregate of shares of Common Stock at the
purchase price per share (the &#147;Option&#148;) as shown on the <I>Notice of Grant of
Stock Options</I>. &#091;The Option is intended to be an Incentive Stock Option under
Section&nbsp;422 of the Internal Revenue Code of 1986, as amended (the &#147;Code&#148;).
Notwithstanding the foregoing, the Option will not qualify as an Incentive
Stock Option, among other events, (i)&nbsp;if the Grantee disposes of the Common
Stock acquired pursuant to the Option at any time during the two year period
following the date of this Agreement or the one year period following the date
on which the Option is exercised, or (ii)&nbsp;if the Grantee is not employed by the
Company or a subsidiary of the Company within the meaning of Section&nbsp;424 of the
Code (a &#147;Subsidiary&#148;) at all times during the period beginning on the date of
this Agreement and ending on the day three months before the date of exercise
of the Option, or (iii)&nbsp;to the extent the aggregate fair market value
(determined as of the time the Option is granted) of the stock subject to
Incentive Stock Options which become exercisable for the first time in any
calendar year exceeds $100,000. To the extent that the Option does not qualify
as an Incentive Stock Option, it shall constitute a separate Non Qualified
Stock Option.&#093;<SUP>1</SUP> &#091;No part of the Option granted hereby is intended to qualify
as an Incentive Stock Option under Section&nbsp;422 of the Internal Revenue Code of
1986, as amended (the &#147;Code&#148;).&#093;<SUP>2</SUP>


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>2.&nbsp;Vesting. </B>(a)&nbsp;The Option is exercisable in installments as provided on
the <I>Notice of Grant of Stock Options</I>. To the extent that the Option has become
exercisable with respect to the number of shares of Common Stock as provided on
the <I>Notice of Grant of Stock Options </I>and subject to the terms and conditions of
the Plan, including without limitation, Section&nbsp;7(c)(1) &#038; (2), the Option may
thereafter be exercised by the Grantee, in whole or in part, at any time or
from time to time prior to the expiration of the Option in accordance with the
requirements set forth in Section&nbsp;7(c)(3) of the Plan, including, without
limitation, the filing of such written form of exercise notice as may be
promulgated by the Committee, and in accordance with applicable tax and other
laws. The Company shall have the right to require the Grantee in connection
with the exercise of the Option to remit to the Company in cash an amount
sufficient to satisfy any federal, state and local withholding tax requirements
related thereto.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;The <I>Notice of Grant of Stock Options </I>indicates each date upon which
the Grantee shall be entitled to exercise the Option with respect to the
additional number of shares of Common Stock granted as indicated provided that
the Grantee has not incurred a termination of employment or service with the
Company and all Subsidiaries (collectively, the Company and all Subsidiaries
shall be referred to herein as the &#147;Employer&#148; and no termination of employment
or service shall be deemed to take place unless the Grantee is no longer
employed by or providing service to the Employer) prior to such date. There
shall be no proportionate or partial vesting in the periods between the Full
Vest Dates specified in the <I>Notice of Grant of Stock Options </I>and all vesting
shall occur only on the Full Vest Dates. Except as otherwise provided in any
employment agreement, consulting agreement, change in control agreement or
similar agreement in effect between the Employer and the



<P>

<HR size="1" width="18%" align="left" noshade>


<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>1</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">This text will appear in agreements for Replacement Options that are intended
to be incentive stock options under Section&nbsp;422 of the Internal Revenue Code of
1986, as amended.</TD>
</TR>

<TR><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>2</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">This text will appear in agreements for Replacement Options that are not
intended to be incentive stock options under Section&nbsp;422 of the Internal
Revenue Code of 1986, as amended.</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">2
</DIV>

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<DIV style="font-family: 'Times New Roman',Times,serif">





<P align="left" style="font-size: 10pt">Grantee on the date specified in the <I>Notice of Grant of Stock Options</I>, no
vesting shall occur after such date as the Grantee ceases to be employed by the
Employer and all unvested Options shall be forfeited at such time.



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Notwithstanding anything herein (except the following sentence) or
in the <I>Notice of Grant of Stock Options </I>to the contrary, the Option shall be
fully vested if the Grantee&#146;s employment with the Employer is terminated on or
within two years after the occurrence of a Change in Control by the Employer
(other than for Cause) or by the Grantee for Good Reason. Except as otherwise
provided in any employment agreement, consulting agreement, change in control
agreement or similar agreement in effect between the Employer and the Grantee
on the date of grant specified in the <I>Notice of Grant of Stock Options</I>, if the
application of the provision in the foregoing sentence, similar provisions in
other stock option or restricted stock grants, and other payments and benefits
payable to the Grantee upon termination of employment (collectively, the
&#147;Company Payments&#148;) would result in the Grantee being subject to the excise tax
payable under Internal Revenue Code Section&nbsp;4999 (the &#147;Excise Tax&#148;), the amount
of any Company Payments shall be automatically reduced to an amount one dollar
less than an amount that would subject the Grantee to the Excise Tax; <I>provided,
however, </I>that the reduction shall occur only if the reduced Company Payments
received by the Grantee (after taking into account further reductions for
applicable federal, state and local income, social security and other taxes)
would be greater than the unreduced Company Payments to be received by the
Grantee minus (i)&nbsp;the Excise Tax payable with respect to such Company Payments
and (ii)&nbsp;all applicable federal, state and local income, social security and
other taxes on such Company Payments. If the Company Payments are to be
reduced in accordance with the foregoing, the Company Payments shall be reduced
as mutually agreed between the Employer and the Grantee or, in the event the
parties cannot agree, in the following order (1)&nbsp;acceleration of vesting of any
option where the exercise price exceeds the fair market value of the underlying
shares at the time the acceleration would otherwise occur, (2)&nbsp;any lump sum
severance based on a multiple of base salary or bonus, (3)&nbsp;any other cash
amounts payable to the Grantee, (4)&nbsp;any benefits valued as parachute payments,
and (5)&nbsp;acceleration of vesting of any equity not covered by (1)&nbsp;above.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>3.&nbsp;Option Term. </B>(a)&nbsp;Except as otherwise provided in the next sentence or
in the Plan, the Option shall expire on the Expiration Date shown on the <I>Notice
of Grant of Stock Options</I>. In the event of termination of employment or
service with the Employer, except as set forth in any employment agreement,
consulting agreement, change in control agreement or similar agreement in
effect between the Employer and the Grantee on the date of grant specified in
the <I>Notice of Grant of Stock Options</I>, the vested portion of the Option shall
expire on the earlier of (i)&nbsp;the Expiration Date, or (ii) (A)&nbsp;subject to (E)
below, three months after such termination if such termination is for any
reason other than death, retirement, or long-term disability, (B)&nbsp;two years
after such termination if such termination is due to the Grantee&#146;s retirement,
(C)&nbsp;one year after the termination if such termination is due to the Grantee&#146;s
death or long-term disability, (D)&nbsp;the occurrence of the Cause event if such
termination is for Cause or Cause existed at the time of such termination
(whether then known or later discovered) or (E)&nbsp;one year after such termination
if such termination is at any time within two years after the occurrence of a
Change in Control and is by the Employer without Cause or by the Grantee for
Good Reason.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;For purposes of this Agreement, &#147;Cause&#148; shall mean (i)&nbsp;in the case
where there is no employment agreement, consulting agreement, change in control
agreement or similar agreement in effect between the Company and the Grantee on
the date of grant specified in the <I>Notice of Grant of Stock Options </I>(or where
there is such an agreement but it does not define &#147;cause&#148; (or words of like
import)) (A)&nbsp;the willful and continued failure by the Grantee substantially to
perform his or her duties and obligations to the Employer, including without
limitation, repeated refusal to follow the reasonable directions of the
Employer, knowing violation of law in the course of performance of the duties
of the Grantee&#146;s employment with the Employer, repeated absences from work
without a reasonable excuse, and intoxication with alcohol or illegal drugs
while on the Employer&#146;s premises during regular business hours (other than any
such failure resulting from his or her incapacity due to physical or mental
illness); (B)&nbsp;fraud or material dishonesty against the Employer; or (C)&nbsp;a
conviction or plea of guilty or nolo contendere to a felony or a crime
involving material dishonesty or (ii)&nbsp;in the case where there is an employment
agreement, consulting agreement, change in control agreement or similar
agreement in effect between the Employer and the Grantee on the date of grant
specified in the <I>Notice of Grant of Stock Options </I>that defines &#147;cause&#148; (or
words of like import), as defined under such agreement. For purposes of this
Section&nbsp;3(b), no act, or failure to act, on a Grantee&#146;s part shall be
considered &#147;willful&#148; unless done, or omitted to be done, by the Grantee in bad
faith and without reasonable belief that his or her action or omission was in
the best interest of the Employer. Any determination of Cause made prior to a
Change in Control shall be made by the Committee in its sole discretion.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;For purposes of this Agreement, &#147;Good Reason&#148; shall mean (i)&nbsp;in the
case where there is no employment agreement, consulting agreement, change in
control agreement or similar agreement in effect between the Employer and the
Grantee on the date of grant specified in the <I>Notice of Grant of Stock Options</I>
(or where there is such an agreement but it does not define &#147;good reason&#148; (or
words of like import)) a termination of employment by the Grantee within one
hundred twenty (120)&nbsp;days after the occurrence of one of the following events
after the occurrence of a Change in Control unless such events are fully
corrected in all material respects by the Employer within thirty (30)&nbsp;days
following written notification by the Grantee to the Employer that Grantee
intends to terminate his employment hereunder for one of the reasons set forth
below: (A) (1)&nbsp;any


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<P align="left" style="font-size: 10pt">material diminution in the Grantee&#146;s duties and responsibilities from
that which exists immediately prior to a Change in Control (except in each case
in connection with the termination of the Grantee&#146;s employment for Cause or as
a result of the Grantee&#146;s death, or temporarily as a result of the Grantee&#146;s
illness or other absence), or (2)&nbsp;the assignment to the Grantee of duties and
responsibilities materially inconsistent with the position held by the Grantee;
(B)&nbsp;any material breach by the Employer of any material provision of any
written agreement with the Grantee or failure to timely pay any compensation
obligation to the Grantee; (C)&nbsp;a reduction in the Grantee&#146;s annual base salary
or target bonus opportunity (if any) from that which exists immediately prior
to a Change in Control; or (D)&nbsp;if the Grantee is based at the Employer&#146;s
principal executive office, any relocation therefrom or, in any event, a
relocation of the Grantee&#146;s primary office of more than fifty (50)&nbsp;miles from
the location immediately prior to a Change in Control; or (ii)&nbsp;in the case
where there is an employment agreement, consulting agreement, change in control
agreement or similar agreement in effect between the Employer and the Grantee
on the date of grant specified in the <I>Notice of Grant of Stock Options </I>that
defines &#147;good reason&#148; (or words of like import), as defined under such
agreement.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>4.&nbsp;Restrictions on Transfer of Option. </B>The Option granted hereby shall
not be transferable other than by will or by the laws of descent and
distribution. During the lifetime of the Grantee, this Option shall be
exercisable only by the Grantee. In addition, except as otherwise provided in
this Agreement, the Option shall not be assigned, negotiated, pledged or
hypothecated in any way (whether by operation of law or otherwise), and the
Option shall not be subject to execution, attachment or similar process. Upon
any other attempt to transfer, assign, negotiate, pledge or hypothecate the
Option, or in the event of any levy upon the option by reason of any execution,
attachment, or similar process contrary to the provisions hereof, the Option
shall immediately become null and void. Notwithstanding the foregoing
provisions of this Section&nbsp;4, subject to the approval of the Committee in its
sole and absolute discretion and to any conditions that the Committee may
prescribe, the Grantee may, upon providing written notice to the Company, elect
to transfer the Option to members of his or her immediate family, including,
but not limited to, children, grandchildren and spouse or to trusts for the
benefit of such immediate family members or to partnerships in which such
family members are the only partners; provided, however, that no such transfer
may be made in exchange for consideration.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>5.&nbsp;Rights of a Stockholder. </B>The Grantee shall have no rights as a
stockholder with respect to any shares of Common Stock subject to this Option
prior to the date of issuance to the Grantee of a certificate or certificates
for such shares. No adjustment shall be made for dividends in cash or other
property, distributions, or other rights with respect to such shares for which
the record date is prior to the date upon which the Grantee shall become the
holder of record therefor.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>6.&nbsp;Compliance with Law and Regulations. </B>This award and any obligation of
the Company hereunder shall be subject to all applicable federal, state and
local laws, rules and regulations and to such approvals by any government or
regulatory agency as may be required. The Company shall be under no obligation
to effect the registration pursuant to federal securities laws of any interests
in the Plan or any shares of Common Stock to be issued hereunder or to effect
similar compliance under any state laws. The Company shall not be obligated to
cause to be issued or delivered any certificates evidencing shares of Common
Stock pursuant to this Agreement unless and until the Company is advised by its
counsel that the issuance and delivery of such certificates is in compliance
with all applicable laws, regulations of governmental authority and the
requirements of any securities exchange on which shares of Common Stock are
traded. The Committee may require, as a condition of the issuance and delivery
of certificates evidencing shares of Common Stock pursuant to the terms hereof,
that the recipient of such shares make such agreements and representations, and
that such certificates bear such legends, as the Committee, in its sole
discretion, deems necessary or desirable. Except to the extent preempted by
any applicable federal law, this Agreement shall be construed and administered
in accordance with the laws of the State of New York without reference to its
principles of conflicts of law.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>7.&nbsp;Grantee Bound by Plan. </B>The Grantee acknowledges receipt of a copy of
the Plan and agrees to be bound by all the terms and provisions thereof. The
Plan is incorporated herein by reference, and any capitalized term used but not
defined herein shall have the same meaning as in the Plan. To the extent that
this Agreement is silent with respect to, or in any way inconsistent with, the
terms of the Plan, the provisions of the Plan shall govern and this Agreement
shall be deemed to be modified accordingly.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>8.&nbsp;Notices. </B>Any notice or communication given hereunder shall be in
writing and shall be deemed given when delivered in person, or by United States
mail, at the following addresses: (i)&nbsp;if to the Employer, to: Regeneron
Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591,
Attention: Secretary, and (ii)&nbsp;if to the Grantee, to: the Grantee at
Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY
10591, or, if the Grantee has terminated employment, to the last address for
the Grantee indicated in the records of the Employer, or such other address as
the relevant party shall specify at any time hereafter in accordance with this
Section&nbsp;8.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>9.&nbsp;No Obligation to Continue Employment. </B>This Agreement does not
guarantee that the Employer will employ the Grantee for any specified time
period, nor does it modify in any respect the Grantee&#146;s employment or
compensation.



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<DOCUMENT>
<TYPE>EX-99.D.9
<SEQUENCE>9
<FILENAME>y69289exv99wdw9.htm
<DESCRIPTION>EX-99.D.9 FORM OF REPLACEMENT OPTION AGREEMENT AND NOTICE OF GRANT OF REPLACEMENT OPTIONS
<TEXT>
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<TITLE>EXHIBIT 99.D.9</TITLE>
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<P align="right" style="font-size: 10pt">EXHIBIT(d)(9)


<P align="center" style="font-size: 10pt"><B>Form of Replacement Option Agreement and<BR>
Notice of Grant of Replacement Options for Senior Vice Presidents<BR>
and Executive Vice Presidents of Regeneron Pharmaceuticals, Inc.</B>


<P>

<HR size="1" width="100%" align="left" noshade>

<P align="left" style="font-size: 10pt; margin-left: 50%"><B>Regeneron Pharmaceuticals, Inc.<BR>
ID: </B>&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;

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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>Notice of Grant of Stock Options</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>777 Old Saw Mill River Road</B></TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>Option Agreement for Replacement</B><BR><B>Option Awards</B>

</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Tarrytown, New York 10591</B></TD>
    <TD>&nbsp;</TD>
</TR>


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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>&#091;OPTIONEE NAME&#093;</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Option Number:</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap colspan="3" align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>&#091;OPTIONEE ADDRESS&#093;</B>
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Plan:</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top"><B>2004</B></TD>
    <TD nowrap valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>ID</B>
</TD>
    <TD>&nbsp;</TD>
    <TD nowrap colspan="3" align="center" valign="top">&#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;
</TD>
    <TD>&nbsp;</TD>
</TR>


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<P align="left" style="font-size: 10pt">Effective &#060;date&#062; (the Grant Date) you have been granted a Non-Qualified
Stock Option to buy &#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093; shares of Regeneron Pharmaceuticals, Inc. (the
Company) stock at &#091;$&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093; per share.


<P align="left" style="font-size: 10pt">The total option price of the shares granted is &#091;$ &#093;.


<P align="left" style="font-size: 10pt">The Stock Option becomes fully vested with respect to all shares underlying the
option on the date the Company&#146;s Products (as defined below) have achieved
aggregate, worldwide gross sales of at least US$100&nbsp;million during any
consecutive twelve-month period (as determined by the Board in accordance with
GAAP) based on sales directly by the Company and/or its licensees, affiliates,
and distributors (the &#147;Milestone Date&#148;), unless the Milestone Date occurs
before the third anniversary of the Grant Date, in which case all of the shares
underlying the option becomes fully vested on the third anniversary of the
Grant Date. The date of such vesting is referred to in the enclosed Option
Agreement as the &#147;Full Vest Date.&#148; As used above, the term &#147;Products&#148; shall
mean the VEGF Trap, IL-1 Trap, IL-4/13 Trap, AXOKINE and any other
pharmaceutical or diagnostic product(s) of the Company that result from the
Company&#146;s research and development programs. Sales of the Company&#146;s Products
outside the United States shall be converted to dollars using the month-end
spot rates published by <I>The Wall Street Journal</I>, Eastern Edition and a method
of conversion consistent with the Company&#146;s (or its licensee&#146;s, as applicable)
customary and usual procedures for currency conversion.


<P>

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<P align="left" style="font-size: 10pt">The Non-Qualified Stock Option expires on &#091;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#093;* (the &#147;Expiration Date&#148;).




<P>

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<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right">*</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">Date to be the later of (i)&nbsp;the remaining term of the tendered option this
new option replaces, and (ii)&nbsp;6&nbsp;years from the Grant Date.</TD>
</TR>

</TABLE>


<P align="left" style="font-size: 10pt">You and the Company agree that these options are granted under and governed by
the terms and conditions of the Company&#146;s 2000 Long-Term Incentive Plan as
amended and the enclosed Option Agreement, both of which are attached and made
a part of this document.



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<P align="center" style="font-size: 10pt"><B>REGENERON PHARMACEUTICALS, INC.<BR>
Non-Qualified Stock Option</B>



<P align="center" style="font-size: 10pt"><B>OPTION AGREEMENT<BR>
PURSUANT TO THE<BR>
2000 LONG-TERM INCENTIVE PLAN</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;THIS AGREEMENT, made as of the date on the <I>Notice of Grant of Stock
Options</I>, by and between Regeneron Pharmaceuticals, Inc., a New York corporation
(the &#147;Company&#148;), and the employee named on the <I>Notice of Grant of Stock Options</I>
(the &#147;Grantee&#148;);


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;WHEREAS, the Grantee is an employee of the Company and the Company desires
to afford the Grantee the opportunity to acquire or enlarge the Grantee&#146;s stock
ownership in the Company so that the Grantee may have a direct proprietary
interest in the Company&#146;s success; and


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;WHEREAS, the Committee administering the 2000 Long-Term Incentive Plan
(the &#147;Plan&#148;) has granted (as of the effective date of grant specified in the
<I>Notice of Grant of Stock Options</I>) to the Grantee a Stock Option to purchase the
number of shares of the Company&#146;s Common Stock ($.001 par value) (the &#147;Common
Stock&#148;) as set forth in the <I>Notice of Grant of Stock Options</I>.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOW, THEREFORE, in consideration of the covenants and agreements herein
contained, the parties agree as follows:


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>1.&nbsp;Grant of Award. </B>Pursuant to Section&nbsp;7 of the Plan, the Company grants
to the Grantee, subject to the terms and conditions of the Plan and subject
further to the terms and conditions set forth here, the option to purchase from
the Company all or any part of an aggregate of shares of Common Stock at the
purchase price per share (the &#147;Option&#148;) as shown on the <I>Notice of Grant of
Stock Options</I>. No part of the Option granted hereby is intended to qualify as
an Incentive Stock Option under Section&nbsp;422 of the Internal Revenue Code of
1986, as amended (the &#147;Code&#148;).


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>2.&nbsp;Vesting. </B>(a)&nbsp;The Option is exercisable as provided on the <I>Notice of
Grant of Stock Options</I>. To the extent that the Option has become exercisable
as provided on the <I>Notice of Grant of Stock Options </I>and subject to the terms
and conditions of the Plan, including without limitation, Section&nbsp;7(c)(1) &#038;
(2), the Option may thereafter be exercised by the Grantee, in whole or in
part, at any time or from time to time prior to the expiration of the Option in
accordance with the requirements set forth in Section&nbsp;7(c)(3) of the Plan,
including, without limitation, the filing of such written form of exercise
notice as may be promulgated by the Committee, and in accordance with
applicable tax and other laws. The Company shall have the right to require the
Grantee in connection with the exercise of the Option to remit to the Company
in cash an amount sufficient to satisfy any federal, state and local
withholding tax requirements related thereto.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;The <I>Notice of Grant of Stock Options </I>describes the date (the &#147;Full
Vest Date&#148;) upon which the Grantee shall be entitled to exercise the Option
provided that the Grantee has not incurred a termination of employment or
service with the Company and all Subsidiaries (collectively, the Company and
all Subsidiaries shall be referred to herein as the &#147;Employer&#148; and no
termination of employment or service shall be deemed to take place unless the
Grantee is no longer employed by or providing service to the Employer) prior to
such date. There shall be no proportionate or partial vesting prior to the
Full Vest Date specified in the <I>Notice of Grant of Stock Options </I>and all
vesting shall occur only on the Full Vest Date. Except as otherwise provided in
any employment agreement, consulting agreement, change in control agreement or
similar agreement in effect between the Employer and the Grantee on the date
specified in the <I>Notice of Grant of Stock Options</I>, no vesting shall occur after
such date as the Grantee ceases to be employed by the Employer (or serve as a
member of the Board of Directors, as the case may be) and all unvested Options
shall be forfeited at such time.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;&#091;If Grantee makes payment upon exercise of the Option by delivering
shares of Common Stock owned by the Grantee for at least six months prior to
the date of exercise, the Grantee shall be granted a new option (a &#147;Reload
Option&#148;) on the date of exercise for a number of shares equal to the number of
shares surrendered by the Grantee upon exercise, subject to the availability of
shares of Common Stock under the Plan at the time of such exercise. Such
Reload Option shall be granted at an exercise price equal to the Fair Market
Value (as defined in the Plan) of a share of Common Stock on the date of grant,
shall expire on the date on which the original Option would have expired, and
shall be fully vested; provided, however, that the Reload Option may not be
exercised until the date that is six months after the date of grant. The
Reload Option shall otherwise be subject to the same terms and conditions as
the original Option; provided, however, that the exercise of the Reload Option
shall not entitle the Grantee to any further Reload grant.&#093;<SUP>1</SUP>



<P>

<HR size="1" width="18%" align="left" noshade>


<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top">
    <TD width="1%" nowrap align="right"><SUP>1</SUP></TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="96%">This text will only appear in Replacement Options granted in exchange for
options which currently have these &#147;reload&#148; provisions.</TD>
</TR>

</TABLE>


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<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;Notwithstanding anything herein (except the following sentence) or in
the <I>Notice of Grant of Stock Options </I>to the contrary, the Option shall be fully
vested if the Grantee&#146;s employment with the Employer (or serve as a member of
the Board of Directors, as the case may be) is terminated on or within two
years after the occurrence of a Change in Control by the Employer (other than
for Cause) or by the Grantee for Good Reason. Except as otherwise provided in
any employment agreement, consulting agreement, change in control agreement or
similar agreement in effect between the Employer and the Grantee on the date of
grant specified in the <I>Notice of Grant of Stock Options</I>, if the application of
the provision in the foregoing sentence, similar provisions in other stock
option or restricted stock grants, and other payments and benefits payable to
the Grantee upon termination of employment (collectively, the &#147;Company
Payments&#148;) would result in the Grantee being subject to excise tax payable
under Internal Revenue Code Section&nbsp;4999 (the Excise Tax&#148;), the amount of any
Company Payments shall be automatically reduced to an amount one dollar less
than an amount that would subject the Grantee to the Excise Tax; provided,
however, that the reduction shall occur only if the reduced Company Payments
received by the Grantee (after taking into account further reductions for
applicable federal, state and local income, social security and other taxes)
would be greater than the unreduced Company Payments to be received by the
Grantee minus (i)&nbsp;the Excise Tax payable with respect to such Company Payments
and (ii)&nbsp;all applicable federal, state and local income, social security and
other taxes on such Company Payments. If the Company Payments are to be
reduced in accordance with the foregoing, the Company Payments shall be reduced
as mutually agreed between the Employer and the Grantee or, in the event the
parties cannot agree, in the following order (1)&nbsp;acceleration of vesting of any
option where the exercise price exceeds the fair market value of the underlying
shares at the time the acceleration would otherwise occur, (2)&nbsp;any lump sum
severance based on a multiple of base salary or bonus, (3)&nbsp;any other cash
amounts payable to the Grantee, (4)&nbsp;any benefits valued as parachute payments,
and (5)&nbsp;acceleration of vesting of any equity not covered by (1)&nbsp;above.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>3.&nbsp;Option Term. </B>(a)&nbsp;Except as otherwise provided in the next sentence or
in the Plan, the Option shall expire on the Expiration Date shown on the <I>Notice
of Grant of Stock Options</I>. In the event of termination of employment or
service with the Employer (including, by way of example, termination of service
as a member of the Board of Directors), except as set forth in any employment
agreement, consulting agreement, change in control agreement or similar
agreement in effect between the Employer and the Grantee on the date of grant
specified in the <I>Notice of Grant of Stock Option</I>, the vested portion of the
Option shall expire on the earlier of (i)&nbsp;the Expiration Date, or (ii)(A)
subject to (E)&nbsp;below, three months after such termination if such termination
is for any reason other than death, retirement, or long-term disability, (B)
two years after such termination if such termination is due to the Grantee&#146;s
retirement, (C)&nbsp;one year after the termination if such termination is due to
the Grantee&#146;s death or long-term disability, (D)&nbsp;the occurrence of the Cause
event if such termination is for Cause or Cause existed at the time of such
termination (whether then known or later discovered) or (E)&nbsp;one year after such
termination if such termination is at any time within two years after the
occurrence of a Change in Control and is by the Employer without Cause or by
the Grantee for Good Reason.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;For purposes of this Agreement, &#147;Cause&#148; shall mean (i)&nbsp;in the case
where there is no employment agreement, consulting agreement, change in control
agreement or similar agreement in effect between the Company and the Grantee on
the date of grant specified in the <I>Notice of Grant of Stock Options </I>(or where
there is such an agreement but it does not define &#147;cause&#148; (or words of like
import)) (A)&nbsp;the willful and continued failure by the Grantee substantially to
perform his or her duties and obligations to the Employer, including without
limitation, repeated refusal to follow the reasonable directions of the
Employer, knowing violation of law in the course of performance of the duties
of the Grantee&#146;s employment with the Employer, repeated absences from work
without a reasonable excuse, and intoxication with alcohol or illegal drugs
while on the Employer&#146;s premises during regular business hours (other than any
such failure resulting from his or her incapacity due to physical or mental
illness); (B)&nbsp;fraud or material dishonesty against the Employer; or (C)&nbsp;a
conviction or plea of guilty or nolo contendere to a felony or a crime
involving material dishonesty or (ii)&nbsp;in the case where there is an employment
agreement, consulting agreement, change in control agreement or similar
agreement in effect between the Employer and the Grantee on the date of grant
specified in the <I>Notice of Grant of Stock Options </I>that defines &#147;cause&#148; (or
words of like import), as defined under such agreement. For purposes of this
Section&nbsp;3(b), no act, or failure to act, on a Grantee&#146;s part shall be
considered &#147;willful&#148; unless done, or omitted to be done, by the Grantee in bad
faith and without reasonable belief that his or her action or omission was in
the best interest of the Employer. Any determination of Cause made prior to a
Change in Control shall be made by the Committee in its sole discretion.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;For purposes of this Agreement, &#147;Good Reason&#148; shall mean (i)&nbsp;in the
case where there is no employment agreement, consulting agreement, change in
control agreement or similar agreement in effect between the Employer and the
Grantee on the date of grant specified in the <I>Notice of Grant of Stock Options</I>
(or where there is such an agreement but it does not define &#147;good reason&#148; (or
words of like import)) a termination of employment or services by the Grantee
within one hundred twenty (120)&nbsp;days after the occurrence of one of the
following events after the occurrence of a Change in Control unless such events
are fully corrected in all material respects by the Employer within thirty (30)
days following written notification by the Grantee to the Employer that Grantee
intends to terminate his employment hereunder for one of the reasons set forth
below: (A) (1)&nbsp;any material diminution in the Grantee&#146;s duties and
responsibilities from that which exists immediately prior to a


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<P align="left" style="font-size: 10pt">Change in Control (except in each case in connection with the termination
of the Grantee&#146;s employment or services for Cause or as a result of the
Grantee&#146;s death, or temporarily as a result of the Grantee&#146;s illness or other
absence), or (2)&nbsp;the assignment to the Grantee of duties and responsibilities
materially inconsistent with the position held by the Grantee; (B)&nbsp;any material
breach by the Employer of any material provision of any written agreement with
the Grantee or failure to timely pay any compensation obligation to the
Grantee; (C)&nbsp;a reduction in the Grantee&#146;s annual base salary or target bonus
opportunity (if any) from that which exists immediately prior to a Change in
Control; or (D)&nbsp;if the Grantee is based at the Employer&#146;s principal executive
office, any relocation therefrom or, in any event, a relocation of the
Grantee&#146;s primary office of more than fifty (50)&nbsp;miles from the location
immediately prior to a Change in Control; or (ii)&nbsp;in the case where there is an
employment agreement, consulting agreement, change in control agreement or
similar agreement in effect between the Employer and the Grantee on the date of
grant specified in the <I>Notice of Grant of Stock Options </I>that defines &#147;good
reason&#148; (or words of like import), as defined under such agreement.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>4.&nbsp;Restrictions on Transfer of Option. </B>The Option granted hereby shall
not be transferable other than by will or by the laws of descent and
distribution. During the lifetime of the Grantee, this Option shall be
exercisable only by the Grantee. In addition, except as otherwise provided in
this Agreement, the Option shall not be assigned, negotiated, pledged or
hypothecated in any way (whether by operation of law or otherwise), and the
Option shall not be subject to execution, attachment or similar process. Upon
any other attempt to transfer, assign, negotiate, pledge or hypothecate the
Option, or in the event of any levy upon the option by reason of any execution,
attachment, or similar process contrary to the provisions hereof, the Option
shall immediately become null and void. Notwithstanding the foregoing
provisions of this Section&nbsp;4, subject to the approval of the Committee in its
sole and absolute discretion and to any conditions that the Committee may
prescribe, the Grantee may, upon providing written notice to the Company, elect
to transfer the Option to members of his or her immediate family, including,
but not limited to, children, grandchildren and spouse or to trusts for the
benefit of such immediate family members or to partnerships in which such
family members are the only partners; provided, however, that no such transfer
may be made in exchange for consideration.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>5.&nbsp;Rights of a Stockholder. </B>The Grantee shall have no rights as a
stockholder with respect to any shares of Common Stock subject to this Option
prior to the date of issuance to the Grantee of a certificate or certificates
for such shares. No adjustment shall be made for dividends in cash or other
property, distributions, or other rights with respect to such shares for which
the record date is prior to the date upon which the Grantee shall become the
holder of record therefor.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>6.&nbsp;Compliance with Law and Regulations. </B>This award and any obligation of
the Company hereunder shall be subject to all applicable federal, state and
local laws, rules and regulations and to such approvals by any government or
regulatory agency as may be required. The Company shall be under no obligation
to effect the registration pursuant to federal securities laws of any interests
in the Plan or any shares of Common Stock to be issued hereunder or to effect
similar compliance under any state laws. The Company shall not be obligated to
cause to be issued or delivered any certificates evidencing shares of Common
Stock pursuant to this Agreement unless and until the Company is advised by its
counsel that the issuance and delivery of such certificates is in compliance
with all applicable laws, regulations of governmental authority and the
requirements of any securities exchange on which shares of Common Stock are
traded. The Committee may require, as a condition of the issuance and delivery
of certificates evidencing shares of Common Stock pursuant to the terms hereof,
that the recipient of such shares make such agreements and representations, and
that such certificates bear such legends, as the Committee, in its sole
discretion, deems necessary or desirable. Except to the extent preempted by
any applicable federal law, this Agreement shall be construed and administered
in accordance with the laws of the State of New York without reference to its
principles of conflicts of law.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>7.&nbsp;Grantee Bound by Plan. </B>The Grantee acknowledges receipt of a copy of
the Plan and agrees to be bound by all the terms and provisions thereof. The
Plan is incorporated herein by reference, and any capitalized term used but not
defined herein shall have the same meaning as in the Plan. To the extent that
this Agreement is silent with respect to, or in any way inconsistent with, the
terms of the Plan, the provisions of the Plan shall govern and this Agreement
shall be deemed to be modified accordingly.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>8.&nbsp;Notices. </B>Any notice or communication given hereunder shall be in
writing and shall be deemed given when delivered in person, or by United States
mail, at the following addresses: (i)&nbsp;if to the Employer, to: Regeneron
Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591,
Attention: Secretary, and (ii)&nbsp;if to the Grantee, to: the Grantee at
Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY
10591, or, if the Grantee has terminated employment, to the last address for
the Grantee indicated in the records of the Employer, or such other address as
the relevant party shall specify at any time hereafter in accordance with this
Section&nbsp;8.


<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>9.&nbsp;No Obligation to Continue Employment. </B>This Agreement does not
guarantee that the Employer will employ the Grantee for any specified time
period, nor does it modify in any respect the Grantee&#146;s employment or
compensation.



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