<SUBMISSION>
<ACCESSION-NUMBER>0000950123-04-002555
<TYPE>8-K
<PUBLIC-DOCUMENT-COUNT>2
<PERIOD>20040227
<ITEMS>5
<ITEMS>7
<FILING-DATE>20040301
<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>
<FILING-VALUES>
<FORM-TYPE>8-K
<ACT>34
<FILE-NUMBER>000-19034
<FILM-NUMBER>04637381
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>777 OLD SAW MILL RIVER RD
<CITY>TARRYTOWN
<STATE>NY
<ZIP>10591-6707
<PHONE>9143477000
</BUSINESS-ADDRESS>
</FILER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>y94739e8vk.htm
<DESCRIPTION>REGENERON PHARMACEUTICALS, INC.
<TEXT>
<HTML>
<HEAD>
<TITLE>REGENERON PHARMACEUTICALS, INC.</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="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: 10pt"><HR align="center" size="1" noshade width="25%">


<P align="center" style="font-size: 18pt"><B>FORM 8-K</B>


<P align="center" style="font-size: 12pt"><B>CURRENT REPORT</B>



<P align="center" style="font-size: 12pt"><B>PURSUANT TO SECTION 13 OR 15(d) OF THE</B>



<P align="center" style="font-size: 12pt"><B>SECURITIES EXCHANGE ACT OF 1934</B>



<P align="center" style="font-size: 10pt">Date of Report (Date of earliest event reported) <B>March&nbsp;1, 2004 (February&nbsp;27, 2004)</B>


<P align="center" style="font-size: 24pt"><B>REGENERON PHARMACEUTICALS, INC.</B>

<DIV align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="80%"></DIV>


<DIV align="center" style="font-size: 10pt">(Exact name of registrant as specified in its charter)</DIV>


<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="30%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
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<TR valign="bottom">
    <TD align="center" valign="top">NEW YORK
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">0-19034
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">No.&nbsp;13-3444607</TD>
</TR>

<TR style="font-size: 1px">
    <TD colspan="5" valign="top" align="left"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">(State or other jurisdiction<BR>
of incorporation)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(Commission<BR>
File Number)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(IRS Employer<BR>
Identification No.)</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="47%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="47%">&nbsp;</TD>
</TR>
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<TR valign="bottom">
    <TD align="center" valign="top">777 OLD SAW MILL RIVER ROAD, TARRYTOWN, NY
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;10591-6707<BR></TD>
</TR>

<TR style="font-size: 1px">
    <TD colspan="3" valign="top" align="left"><HR size="1" noshade>&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">(Address of principal executive offices)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(Zip Code)</TD>
</TR>
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</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">Registrant&#146;s telephone number, including area code (914)&nbsp;347-7000



<P align="center" style="font-size: 10pt">NOT APPLICABLE


<DIV align="center" style="font-size: 10pt"><HR align="center" size="1" noshade width="15%"></DIV>


<DIV align="center" style="font-size: 10pt">(Former name or former address, if changed since last report)</DIV>




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

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<P align="left" style="font-size: 10pt"><B>INFORMATION TO BE INCLUDED IN REPORT</B>


<!-- link2 "Item&nbsp;5. Other Events and Regulation&nbsp;FD Disclosure." -->

<P align="left" style="font-size: 10pt"><B>Item&nbsp;5. Other Events and Regulation&nbsp;FD Disclosure.</B>



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On February&nbsp;27, 2004, the Company issued a press release, a copy of which
is included as an exhibit to this filing.

<!-- link2 "Item&nbsp;7. Financial Statements and Exhibits." -->

<P align="left" style="font-size: 10pt"><B>Item&nbsp;7. Financial Statements and Exhibits.</B>




<P align="left" style="margin-left:3%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) Exhibits



<P align="left" style="margin-left:6%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;99(a) Press Release dated February&nbsp;27, 2004.


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

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



<P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="40%">
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    <TD width="78%">&nbsp;</TD>
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    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><B>Regeneron Pharmaceuticals, Inc.</B></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><BR>
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">Vice President &#038; General Counsel</TD>
</TR>

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</DIV>



<P align="left" style="font-size: 10pt">Date: March&nbsp;1, 2004


<P align="center" style="font-size: 10pt">3
</DIV>

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</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A
<SEQUENCE>3
<FILENAME>y94739exv99wa.htm
<DESCRIPTION>PRESS RELEASE
<TEXT>
<HTML>
<HEAD>
<TITLE>PRESS RELEASE</TITLE>
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<DIV style="font-family: 'Times New Roman',Times,serif">

<P align="right" style="font-size: 10pt"><B>EXHIBIT 99(a)</B>



<P align="left" style="font-size: 10pt"><B>FOR IMMEDIATE RELEASE</B>



<P align="center" style="font-size: 10pt"><B>REGENERON ANNOUNCES PLANS FOR PHASE IIb STUDY OF IL-1 TRAP AND END OF NOVARTIS<BR>
PARTICIPATION IN IL-1 TRAP PROGRAM</B>



<P align="center" style="font-size: 10pt"><B>Phase IIb Study in Rheumatoid Arthritis Planned for Second Half of 2004</B>


<P align="left" style="font-size: 10pt">Tarrytown, NY (February&nbsp;27, 2004) &#150; Regeneron Pharmaceuticals, Inc. (Nasdaq:
<B>REGN</B>) announced today that it plans to initiate a Phase IIb study of the
Company&#146;s Interleukin-1 (IL-1) Trap for the treatment of rheumatoid arthritis
(RA)&nbsp;in the second half of 2004 and that Novartis Pharma AG notified the
Company today that it has decided to forgo its rights under the parties&#146;
collaboration agreement to jointly develop and commercialize the IL-1 Trap.


<P align="left" style="font-size: 10pt">Regeneron decided to conduct a Phase IIb study based on the recommendation of
an advisory panel of independent medical experts. The panel examined the
results from the Phase II trial of the IL-1 Trap in patients with RA which was
completed in the second half of 2003. The panel concluded that the completed
Phase II trial may not have tested the maximally efficacious dose of the IL-1
Trap and that a new Phase Ilb study should be conducted in a larger patient
population, testing higher doses for a longer period of time. The Phase IIb
trial is expected to begin in the second half of 2004 following completion of
development of a new formulation and patient tolerability studies. In
addition, Regeneron plans to conduct studies of the IL-1 Trap in a variety of
other inflammatory diseases where Interleukin-1 is believed to play a critical
role.


<P align="left" style="font-size: 10pt">After evaluating the results of the Phase II study, Novartis informed Regeneron
that as a condition for participating in the continued clinical development of
the IL-1 Trap, it would require revisions to the terms of the original
agreement applicable to the IL-1 Trap. Regeneron declined to accept revisions
to the collaboration agreement on the terms proposed by Novartis, and Novartis
has elected not to proceed with the joint development of the IL-1 Trap. Under
the terms of the collaboration agreement, which began in March&nbsp;2003, Novartis
has to date paid $102&nbsp;million to Regeneron in up-front payments, equity
investments, and development expenses. Of that total, $13.7&nbsp;million consists
of a loan, which is forgivable when near-term milestones are met. Novartis
also remains obligated to fund development expenses during the nine-month
notice period following its decision. In addition, Regeneron and Novartis each
retain rights under the agreement to elect to collaborate on the development
and commercialization

<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">of other IL-1 antagonists being developed independently by the other party that
are in earlier stages of development.


<P align="left" style="font-size: 10pt">&#147;We are moving the IL-1 Trap development program forward because we believe it
is important to test higher doses in order to fully assess the therapeutic
effect and commercial value of this product candidate in rheumatoid arthritis
as well as other inflammatory diseases. While we were satisfied with the
progress the partnership had made, we did not believe a renegotiation of our
agreement on the terms proposed by Novartis was appropriate,&#148; said Leonard S.
Schleifer, M.D., Ph.D., Regeneron&#146;s President and Chief Executive Officer. &#147;We
are confident in our decision to proceed with the IL-1 Trap program and believe
that interleukin-1 blockade will find a role in the treatment of serious
medical diseases.&#148;



<P align="left" style="font-size: 10pt"><B>About Regeneron</B>


<P align="left" style="font-size: 10pt">Regeneron is a biopharmaceutical company that discovers, develops, and intends
to commercialize therapeutic medicines for the treatment of serious medical
conditions. Regeneron has therapeutic candidates in clinical trials for the
potential treatment of cancer, rheumatoid arthritis, asthma, and obesity and
has preclinical programs in other diseases and disorders.


<P align="left" style="font-size: 10pt">This news release discusses historical information and includes forward-looking
statements about Regeneron and its products, programs, finances, and business,
all of which involve a number of risks and uncertainties, such as risks
associated with preclinical and clinical development of drugs and biologics,
determinations by regulatory and administrative governmental authorities,
competitive factors, technological developments, the availability and cost of
capital, the costs of developing, producing, and selling products, the
potential for any collaboration agreement to be canceled or to terminate
without any product success, and other material risks. A more complete
description of these risks can be found in Regeneron&#146;s filings with the United
States Securities and Exchange Commission, including its Form 10-K for the year
ended December&nbsp;31, 2002 and the Form 10-Q for the quarter ended September&nbsp;30,
2003. Regeneron does not undertake any obligation to update publicly any
forward-looking statement, whether as a result of new information, future
events, or otherwise unless required by law.



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

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="25%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="68%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Contact Information:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</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">Investors:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Media:</TD>
</TR>

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

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

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(914) 345-7640
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(212) 845-5609</TD>
</TR>

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">charles.poole@regeneron.com
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">ltortorete@biosector2.com</TD>
</TR>

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</TABLE>
</DIV>


<P align="left" style="font-size: 10pt">Additional information about Regeneron and recent news releases are available
on Regeneron&#146;s Worldwide Web Home Page at www.regeneron.com




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


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