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<ACCESSION-NUMBER>0001206774-04-001655
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<FILING-DATE>20041117
<DATE-OF-FILING-DATE-CHANGE>20041117
<EFFECTIVENESS-DATE>20041117
<FILER>
<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>
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<FORM-TYPE>DEFA14A
<ACT>34
<FILE-NUMBER>000-19034
<FILM-NUMBER>041151024
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>777 OLD SAW MILL RIVER RD
<CITY>TARRYTOWN
<STATE>NY
<ZIP>10591-6707
<PHONE>9143477000
</BUSINESS-ADDRESS>
</FILER>
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<SEQUENCE>1
<FILENAME>d15720_defa14a.htm
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<A NAME="A001"></A>
<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="3"><B>UNITED
STATES<BR>SECURITIES
AND EXCHANGE COMMISSION<BR>Washington,
D.C. 20549</B></FONT></FONT></P>

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<A NAME="A004"></A>
<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="3"><B>SCHEDULE
14A<BR>(Rule
14a-101)</B></FONT></FONT></P>

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<A NAME="A006"></A>
<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"><B>Proxy Statement
Pursuant to Section 14(a) of the<BR>Securities
Exchange Act of 1934<BR>(Amendment No.)</B></FONT></FONT></P>

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<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Filed by the
Registrant  <FONT FACE="WINGDINGS">x</FONT><BR>Filed by a Party other than the Registrant
<FONT FACE="WINGDINGS">o</FONT></FONT></FONT> </P>

<table width="100%" border="0" cellpadding="0" cellspacing="0">
  <tr>
    <td colspan="2"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Check
      appropriate box:</FONT></FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Wingdings">o&nbsp;</font></td>
    <td width="100%"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Preliminary
      Proxy Statement</FONT></FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Wingdings">o</font><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">Confidential, For
      Use of the Commission Only (as permitted by Rule 14a-6(e)(2))</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Wingdings">o</font><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"> Definitive
      Proxy Statement</FONT></FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Wingdings">o</font><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Definitive Additional
      Materials</FONT></FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Wingdings">x</font><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Soliciting Material
      under Rule 14a-12</FONT></FONT></td>
  </tr>
</table>
<BR>

<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td align="center" style="Border-bottom: solid windowtext 1px"><font size="2" face="Times New Roman, Times, serif">REGENERON
      PHARMACEUTICALS, INC.</font></td>
  </tr>
  <tr>
    <td align="center"><font size="2" face="Times New Roman, Times, serif">(Name
      of Registrant as Specified in Its Charter)</font></td>
  </tr>
</table>
<br>

<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td align="center" style="border-bottom: solid windowtext 1px"><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td align="center"><font size="2" face="Times New Roman, Times, serif">(Name
      of Person(s) Filing Proxy Statement, if Other Than the Registrant)</font></td>
  </tr>
</table><BR>

<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td colspan="2"><font size="2" face="Times New Roman, Times, serif">Payment
      of filing fee (Check the appropriate box):</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Wingdings">x</font><font size="2" face="Times New Roman, Times, serif">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</font></td>
    <td width="100%"><font size="2" face="Times New Roman, Times, serif">No fee
      required.</font></td>
  </tr>
  <tr>
    <td valign="top"><font size="2" face="Wingdings">o</font></td>
    <td><font size="2" face="Times New Roman, Times, serif"> Fee computed on table
      below per Exchange Act Rules 14a-6(i)(1) and 0-11.<br>
      (1) Title of each class of securities to which transaction applies: </font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">(2) Aggregate number
      of securities to which transaction applies:</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, serif"><FONT SIZE="2">(3) Per unit
      price or other underlying value of transaction computed pursuant to Exchange
      Act Rule 0-11 (Set forth the amount on which the filing fee is calculated
      and state how it was determined):</FONT> </FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, serif"><FONT SIZE="2">(4) Proposed
      maximum aggregate value of transaction:</FONT> </FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, serif"><FONT SIZE="2">(5) Total fee
      paid:</FONT></FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td valign="top"><font size="2" face="Wingdings">o</font><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">Fee paid previously
      with preliminary materials:</font></td>
  </tr>
  <tr>
    <td valign="top"><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td valign="top"><font size="2" face="Wingdings">o</font><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font face="Times New Roman, Times, Serif"><font size="2">Check box if
      any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2)
      and identify the filing for which the offsetting fee was paid previously.
      Identify the previous filing by registration statement number, or the form
      or schedule and the date of its filing.</font></font> </td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, serif"><FONT SIZE="2">(1) Amount Previously
      Paid:</FONT> </FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, serif"><FONT SIZE="2">(2) Form, Schedule
      or Registration Statement No.:</FONT> </FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><FONT FACE="Times New Roman, Times, serif"><FONT SIZE="2">(3) Filing Party:</FONT>
      </FONT></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
  </tr>
  <tr>
    <td><font size="2" face="Times New Roman, Times, serif">&nbsp;</font></td>
    <td><font size="2" face="Times New Roman, Times, serif">(4) Date Filed:</font></td>
  </tr>
</table>


<PAGE>


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<A NAME="A002"></A>
<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">E-MAIL
COMMUNICATION FROM ROSS<BR>GROSSMAN,
VICE PRESIDENT OF HUMAN<BR>RESOURCES, TO
ALL EMPLOYEES, SENT ON<BR>NOVEMBER 17,
2004</FONT></FONT></P>

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<P ALIGN="LEFT">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Over
the last several months, Regeneron management and the Compensation Committee of
the Board of Directors have worked together to evaluate the Company&#146;s
long-term incentive compensation programs. Following this evaluation, the
Compensation Committee recommended, and the Board of Directors approved, subject
to shareholder approval, a Stock Option Exchange Program which would provide an
opportunity for eligible employees who hold stock options with a per share
exercise price of at least $18 to exchange those options for a lesser number of
replacement stock options based on the exchange ratios described below. The
replacement stock options would have a per share exercise price equal to the
fair market value of Regeneron Common Stock on the date that the replacement
options are granted. That date will be at least twenty business days after the
Company formally commences an Offer to Exchange to implement the Stock Option
Exchange Program.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para" -->
<P ALIGN="LEFT">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">The
Company has filed preliminary proxy materials with the Securities and Exchange
Commission (the SEC) relating to the proposal to have shareholders approve this
program. You can read the full proxy statement in its preliminary form on our
website <U>(www.regeneron.com</U>) under the Investor Relations page. The
proposal is expected to be voted on by Regeneron&#146;s shareholders at a
special shareholder meeting that will be scheduled once the timing of our
mailing of definitive proxy materials is known. Since that timing will depend on
the duration of any SEC review process, we cannot predict now when the special
shareholder meeting will be convened. However, we hope to be able to hold the
meeting in December 2004 or January 2005. If the shareholders approve the
exchange program, we would expect to grant replacement options under the program
in January 2005 with an exercise price equal to the fair market value of
Regeneron Common Stock on the grant date. This program was proposed because we
and the Board of Directors recognize that the talent and dedicated efforts of
our employees are critical to the Company&#146;s long-term success, and stock
options have proven to be an effective tool to retain, motivate, and reward
employees.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para" -->
<P ALIGN="LEFT">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Regeneron
has not commenced the Stock Option Exchange Program referred to both in this
e-mail and the preliminary proxy materials referred to above. When we commence
the exchange program, we will distribute to each eligible employee appropriate
materials describing the program in detail in order to help you decide whether
you want to participate in the exchange program. Eligible option holders should
read these written materials carefully because they will contain important
information about the program. The Stock Option Exchange Program will remain
open for at least twenty business days and, of course, will be contingent upon
the approval of the shareholders at the special shareholders&#146; meeting and
other terms and conditions.</FONT></FONT></P>





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<!-- MARKER FORMAT-SHEET="Para" -->
<P ALIGN="LEFT">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">I
know that, as you think about the Stock Option Exchange Program, you will have
many questions. Following the commencement of the exchange program, we plan to
communicate further in writing and at meetings in Tarrytown and Rensselaer. At
this point, however, we want to provide answers to some of your likely
questions:</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">How do
I participate in the exchange program?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">We
have not commenced the exchange program. Once the exchange program is commenced,
eligible employees will receive additional information, including an Offer to
Exchange, which will set forth the procedures for tendering your options and
participating in the exchange program.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Who
will be eligible for the exchange program if shareholders approve it?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Regular
Regeneron employees, other than the Chief Executive Officer, who work an average
of at least 20 hours per week and who are actively employed by the Company on
the date the Offer to Exchange expires will be eligible to participate in the
exchange once it is commenced. Participation in the exchange program will be
subject to the conditions specified in the Offer to Exchange, including
obtaining shareholder approval. Employees who meet the eligibility requirements
at the commencement of the exchange program but do not satisfy these
requirements on the expiration date will not be eligible to exchange their
options. The expiration date of the Offer to Exchange is currently expected to
be some time in January 2005, but it could change. Of course, if on the
expiration date you are not actively at work because of illness, vacation,
short-term leave, or other similar reasons, that will not disqualify you from
participating in the program.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">What
if the shareholders do not approve the exchange program?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">The
exchange program is contingent upon the approval of the shareholders at the
special meeting of shareholders. If the shareholders do not approve the exchange
program and you previously elected to participate in the program, that election
will have no effect and your old stock options will continue under their
existing terms and conditions.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">If
I have options that are eligible for exchange, do I have to exchange them for
replacement options?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">No.
The program is completely voluntary. Once the program is commenced, and assuming
shareholder approval of the program, you may exchange all of your eligible
options, some grants but not others, or no options. However, if you choose to
exchange options from a particular grant, you must exchange all options in that
grant.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Will I
receive one option for every option I exchange?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">No.
Options will be exchanged according to exchange ratios that are intended to
reflect the lower value of the existing eligible options, which have per share
exercise prices</FONT></FONT></P>



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<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">2</FONT></FONT></P>

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<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">above the
current stock price of Regeneron&#146;s Common Stock,  and the higher value of the
replacement options, which will have a per share  exercise price equal to the fair market
value of Regeneron&#146;s Common Stock  on the date of the grant of the replacement
options. Since options with a lower  exercise price have a higher value than similar
options with higher exercise  prices, the higher the exercise price of the options
exchanged, the fewer  replacement options you will receive. The exchange ratios (that is,
how many old  options you need to surrender to get one replacement option) for options
with  various exercise prices are shown in the following table.</FONT></FONT></P>


<table border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">Exercise Price</font></td>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">Exchange Ratio
      (# of existing eligible options/# of replacement options)</font></td>
  </tr>
  <tr>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">$18.00-$28.00&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</font></td>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">1.5 to 1</font></td>
  </tr>
  <tr>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">$28.01-$37.00</font></td>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">2 to 1</font></td>
  </tr>
  <tr>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">Above $37</font></td>
    <td nowrap><font size="2" face="Times New Roman, Times, serif">3 to 1</font></td>
  </tr>
</table>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Will
my replacement options have the same vesting schedule as the options I exchange?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">No.
All replacement options issued in the exchange program, including replacement
options exchanged for old, fully vested options, will have a new vesting period.
Replacement options for employees other than the Senior and Executive Vice
Presidents will vest in equal installments over four years (i.e., 25% on each of
the first, second, third, and fourth anniversaries of the replacement options
grant date). Replacement options for the Senior and Executive Vice Presidents
will vest the first time the Company records twelve-month worldwide gross sales
of Company products of at least $100 million, but no earlier than three years
from the grant date. Of course, vesting for all replacement options will be
subject to the option holder&#146;s continued employment on the applicable
vesting date.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Will
the replacement options have a 10 year life?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">No.
Replacement options generally will have the same life as the life remaining on
the exchanged option you turn in. However, if the life remaining on the options
you turn in as part of the exchange is less than 6 years, the term of the
replacement option will be 6 years. For example, if you exchange options granted
in January 2001, which expire in December 2011, your new replacement option
issued in January 2005 will also expire in December 2011. On the other hand, if
you exchange options granted in January 2000, which expire in January 2010, your
new replacement options issued in January 2005 will expire in January 2011
(i.e., 6 years from the date of grant of the replacement options).</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">I
currently have incentive stock options. Will my new options be incentive stock
options?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">If you
surrender incentive stock options for exchange, the replacement options you
receive will be incentive stock options to the extent permitted by IRS rules.
Otherwise, the replacement options will be non-qualified stock options.</FONT></FONT></P>



<!-- MARKER FORMAT-SHEET="Para Center" -->
<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">3</FONT></FONT> </P>

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<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">If I
elect to exchange options, will the exchange itself subject me to any income
taxes?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">No.  The
exchange of options under the exchange program should be treated as a non-taxable
exchange.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">When
will I know the exercise price of my replacement option grants?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">The
exercise price of the replacement options will equal the fair market value of
Regeneron Common Stock on the expiration date of the exchange program. The fair
market value is calculated as the average of the high and low share price on
that date.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">How do
I know if I am eligible to participate? How do I find out how many eligible
options I have and what their exercise prices are?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">We
will provide you with this information when we commence the option exchange
program. You can at any time confirm what options you have, their grant dates,
exercise prices, vesting dates, and other information by going to
<U>www.optionslink.com &lt;http://www.optionslink.com/</U>&gt;. Employees who do
not have their optionslink password should send an email to
<U>optionslink@etrade.com &lt;mailto:optionslink@etrade.com</U>&gt; 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.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">What
will happen if I do nothing in response to the exchange offer?</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para Flush" -->
<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">Nothing
will change. All of your current stock options will continue to be valid and
will continue to vest with continued service. Their exercise price, vesting
schedule, and other terms will not change.</FONT></FONT></P>

<!-- MARKER FORMAT-SHEET="Para" -->
<P ALIGN="LEFT">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">While
many of you may have additional questions at this time, we ask that you please
not contact Human Resources with questions about the exchange program until you
have had the opportunity to read the written materials that will be sent to your
attention concerning the Stock Option Exchange Program, including the Offer to
Exchange. In addition, we plan to schedule meetings in Tarrytown and Rensselaer
to review the exchange program once it is commenced.</FONT></FONT></P>

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<P ALIGN=CENTER>*&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*</P>

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<A NAME="A006"></A>
<P ALIGN="LEFT">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"><B>Additional
Information About the Stock Option Exchange Program and Where to Find It</B></FONT></FONT></P>

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<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"><B>This
does not constitute an offer to holders of options to exchange their options. At
the time the Stock Option Exchange Program is commenced, we will provide
eligible</B></FONT></FONT></P>


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<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">4</FONT></FONT></P>


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<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"><B>employees with
written materials, including an Offer to Exchange, explaining the precise terms,
conditions and timing of, and procedures for accepting, such offer, and will file those
materials with the Securities and Exchange Commission (the SEC). Eligible employees
should carefully read those materials, when they become available, because they will
contain important information about the Stock Option Exchange Program.</B></FONT></FONT></P>

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<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"><B>The
exchange of options contemplated by the Stock Option Exchange Program is also
subject to shareholder approval of an amendment to our 2000 Long-Term Incentive
Plan to expressly authorize the program. In connection with seeking such
shareholder approval at a special meeting of shareholders to be convened as soon
as practicable, on November 17, 2004 we filed with the SEC preliminary forms of,
and expect to file with the SEC definitive forms of, a proxy statement and other
relevant materials. Shareholders should carefully read the applicable proxy
statement and other relevant materials, when they become available, because they
contain or will contain important information concerning the Stock Option
Exchange Program and the proposed amendment to our 2000 Long-Term Incentive Plan
to expressly authorize the program. Regeneron Pharmaceuticals, Inc. and its
directors, executive officers, and certain of its employees may be deemed to be
participants in the solicitation of proxies from our shareholders with respect
to approval of such proposed amendment. Information regarding the names,
affiliations, and interests of the participants in the solicitation is included
in the preliminary form of, and will be included in the definitive form of, the
proxy statement filed or to be filed with the SEC.</B></FONT></FONT></P>

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<P ALIGN="LEFT"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2"><B>Free
copies of the preliminary proxy statement, and the definitive proxy statement,
the Offer to Exchange and related materials (when they are available), and any
other materials filed by Regeneron Pharmaceuticals, Inc. with the SEC, may be
obtained at the SEC&#146;s website at <U>http://www.sec.gov</U> or from
Regeneron at our website <U>www.regeneron.com</U>, or by directing a request to
our Investor Relations Department at 777 Old Saw Mill River Road, Tarrytown, New
York 10591.</B></FONT></FONT></P>

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<P ALIGN="CENTER"><FONT FACE="Times New Roman, Times, Serif"><FONT SIZE="2">5</FONT></FONT> </P>





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