SECURITIES AND EXCHANGE COMMISSION ON JANUARY 22, 2002 REGISTRATION NO. 333-74464 - -------------------------------------------------------------------------------- - -------------------------------------------------------------------------------- SECURITIES AND EXCHANGE COMMISSION WASHINGTON,

~~Stuart A. ~~KOLINSKI, ESQ. GENERAL COUNSEL REGENERON PHARMACEUTICALS, INC.~~ Kolinski, Esq.~~

Approximate date of commencement of proposed sale to the public: From time to time after this Registration Statement becomes effective. ~~If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. [ ]~~


	If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, check the following box. o

	If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. þ

	If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

	If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o


	If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box: o

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act ~~of 1933, other than securities offered only in connection with dividend~~ or ~~interest reinvestment plans, check~~until the ~~following box. [X] If this form is filed to register additional securities for an offering~~registration statement shall become effective on such date as the Securities and Exchange Commission (SEC), acting pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [ ] - --------------- If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [ ] - --------------- If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box. [ ] THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL FILE A FURTHER AMENDMENT SPECIFICALLY STATING THAT THIS REGISTRATION STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF THE SECURITIES ACT OF 1933, AS AMENDED, OR UNTIL THIS REGISTRATION STATEMENT SHALL BECOME EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTIONsaid Section 8(a), ~~MAY DETERMINE. - -------------------------------------------------------------------------------- - --------------------------------------------------------------------------------~~ THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. THE SELLING SECURITYHOLDERS MAY NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER TO SELL THESE SECURITIES AND IT IS NOT SOLICITING OFFERS TO BUY THESE SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED. may determine.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities, and we are not soliciting offers to buy these securities in any state where the offer or sale is not permitted.

~~SUBJECT TO COMPLETION, ~~PRELIMINARY PROSPECTUS~~ DATED ~~JANUARY 22, 2002 $200,000,000~~FEBRUARY 9, 2005~~

REGENERON PHARMACEUTICALS, INC. 5 1/2% CONVERTIBLE SENIOR SUBORDINATED NOTES DUE 2008 AND SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF THE NOTES On October 17, 2001, we issued and sold $200,000,000 aggregate principal amount of our 5 1/2% Convertible Senior Subordinated Notes due 2008may sell from time to time in ~~a private placement. This prospectus will be used by selling securityholders to resell the notes and register and sell~~one or more offerings, together or separately:



•	common stock (including the associated rights to purchase Series A junior participating preferred stock);


•	preferred stock;

•	debt securities; and

•	warrants to purchase debt securities, common stock or preferred stock.

The common stock ~~issuable upon conversion~~ of the notes. The notes are convertible, at the option of the holder, at any time on or prior to maturity into shares of our common stock at a conversion price of approximately $30.25 per share, whichRegeneron Pharmaceuticals, Inc. is equal to a conversion rate of 33.0565 shares per $1,000 principal amount of notes, subject to adjustment. We will pay interest on the notes on April 17 and October 17 of each year, beginning April 17, 2002. The notes will mature on October 17, 2008. We may provisionally redeem some or all of the notes at any time before October 17, 2004 at prices set forth in this prospectus under "Description of Notes -- Provisional Redemption by Regeneron." We may also optionally redeem some or all of the notes at any time on or after October 17, 2004, at prices set forth in this prospectus under "Description of Notes -- Optional Redemption by Regeneron." The notes are unsecured (except to the extent described in this prospectus) and subordinated to our existing and future senior indebtedness. The notes will rank equally with our existing and future senior subordinated indebtedness. We have pledged a portfolio of U.S. government securities as security for the notes, in an amount sufficient to pay the first six scheduled interest payments on the notes. Our common stock is quotedlisted on the Nasdaq National Market under the symbol ~~"REGN." On January 18, 2002,~~“REGN.” Our principal executive offices are located at 777 Old Saw Mill River Road, Tarrytown, NY 10591-6707, telephone (914) 345-7400.

~~Investing in our securities involves risks that are described in the ~~closing bid price~~“Risk Factors” section beginning on page 2 of ~~our common stock as reported on~~this prospectus.~~

We urge you to read carefully this prospectus and the ~~Nasdaq National Market was $27.43 per share. INVESTING IN THE NOTES INVOLVES RISKS THAT ARE DESCRIBED IN THE "RISK FACTORS" SECTION BEGINNING ON PAGE 5 OF THIS PROSPECTUS. If~~accompanying prospectus supplement, which will describe the selling securityholders use any broker-dealers, any commission paid to broker-dealers and, if broker-dealers purchase any notes or shares of common stock as principals, any profits received by such broker-dealers on the resalespecific terms of the ~~notes or shares of common stock may be deemed~~securities being offered to ~~be underwriting discounts or commissions under~~you, before you make your investment decision.

Neither the Securities Act. NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS OR THE ACCOMPANYING PROSPECTUS SUPPLEMENT IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE. and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus or the accompanying prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

~~This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.~~

In this prospectus, ~~"Regeneron," "our~~“Regeneron,” “our company,~~" "we," "us," "the~~” “we,” “us,” “the issuer,~~" "the~~” “the registrant,"” and ~~"our"~~“our” refer to Regeneron Pharmaceuticals, Inc., references to our ~~"common stock"~~“common stock” refer to shares of our common stock, par value $0.001 per share, and shall include the rights attached to such common stock in accordance with our shareholder rights plan, references to our Class A stock refer to our Class A stock, par value $0.001 per share, and shall include the rights attached to such Class A stock in accordance with our shareholder rights plan, and references to our ~~"common shares"~~“common shares” shall mean, collectively, ~~our~~ shares of common stock and shares of Class A stock.

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission using a “shelf” registration process. Under this shelf process, we may sell any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $200,000,000. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

We ~~are subject to the information and reporting requirements of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), under which we~~ file ~~periodic~~ reports, proxy statements, and other information with the SEC. ~~Copies of~~The public may read and copy any materials filed by us at the SEC’s Public Reference Room at 450 Fifth Street, N.W., Washington, D.C. 20549 or on the Internet site maintained by the SEC at http://www.sec.gov. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. Our common stock is listed on the Nasdaq National Market, and these reports, proxy statements, and other information ~~may be examined without charge~~are also available for inspection at the ~~Public Reference Section~~offices of the ~~SEC, 450 Fifth~~Nasdaq Stock Market, 1735 K Street, N.W. ~~Room 1024,~~, Washington, D.C. ~~20549, and~~20006-1504.

This prospectus is part of a registration statement filed by us with the SEC's regional office located at 233 Broadway, New York, NY 10279 or 500 West Madison Street, Suite 1400, Chicago, IL 60600 or on the Internet at http://www.sec.gov. Copies of all or a portion of such materialsSEC. The full registration statement can be obtained from the ~~Public Reference Section of the~~ SEC, ~~upon payment of prescribed fees. Please call the SEC at 800-SEC-0330 for further information about the Public Reference Room.~~as indicated above, or from us.

The SEC allows us to ~~"incorporate~~“incorporate by ~~reference"~~reference” the information we file with ~~them, which means that we can~~the SEC. This permits us to disclose important information to you by referring ~~you~~ to ~~those~~these filed documents. ~~The~~Any information ~~incorporated by reference~~referred to in

this way is considered ~~to be~~ part of this ~~prospectus and information that we file later with the SEC will automatically update and supersede this information.~~prospectus. We incorporate by reference the following documents ~~listed below and all~~that have been filed with the SEC:


	•	our amended Annual Report on Form 10-K/A for the year ended December 31, 2003 filed with the SEC on December 14, 2004;

	•	our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2004 filed with the SEC on May 6, 2004, for the quarter ended June 30, 2004 filed with the SEC on August 5, 2004, and for the quarter ended September 30, 2004 filed with the SEC on November 8, 2004; and


	•	our Current Reports on Form 8-K filed with the SEC on March 1, 2004, April 28, 2004, July 27, 2004 (as to Item 5 only), November 12, 2004, November 17, 2004, December 13, 2004, December 17, 2004, January 6, 2005, January 11, 2005 and February 4, 2005.

Any information in any of the foregoing documents will automatically be deemed to be modified or superceded to the extent that information in this prospectus or in a later filed document that is incorporated or deemed to be incorporated herein by reference modifies or replaces such information.

We also incorporate by reference any future filings ~~we make~~(other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items) made with the SEC ~~after the date of the initial registration statement and prior~~pursuant to ~~effectiveness of the registration statement and any filings thereafter and prior to the termination of this offering with the SEC under Section~~Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934: (1) our definitive Proxy Statements filed on April 30, 2001 and November 21, 2001; (2) our Annual Report on Form 10-K for the year ended December 31, 2000; (3) our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2001, June 30, 2001 and September 30, 2001; (4) our Current Reports on Form 8-K filed on October 12, 2001; and (5) the description of our common stock contained in Item 1 of our Registration Statement on Form 8-A filed on February 20, 1991,1934, as amended (the “Exchange Act”), until we file a post-effective amendment which indicates the termination of the offering of the securities made by this prospectus. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supercede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

We will provide to each person, including any beneficial owner, to whom a ~~Form 8 filed on March 27, 1991. i~~ ~~You may~~prospectus is delivered, without charge upon written or oral request, a copy of ~~these filings,~~any or all of the documents that are incorporated by reference into this prospectus, other than exhibits which are specifically incorporated by reference into such documents. Requests should be directed to the Investor Relations Department at ~~no cost, by writing or telephoning us at the following address:~~ Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707 (917) 347-7000 Attention: Murray A. Goldberg Chief Financial Officer Exhibits to the filings will not be sent, however, unless those exhibits have specifically been incorporated10591 or by ~~reference in this document. ii~~ calling us at 914-345-7400.

This prospectus and the documents incorporated by reference herein include forward-looking ~~statements. We have based these forward-looking~~ statements on our current expectations and projections about future events. These forward-looking statements include, among other things, statements relating to: - our anticipated business strategies; - our anticipated clinical trials; - our intention to introduce new product candidates; - our relationships with collaborators; - anticipated trends in our businesses; - future capital expenditures; and - our ability to conduct clinical trials and obtain regulatory approval. The forward-looking statements included in this prospectus or inwithin the ~~documents incorporated by reference herein are subject to risks, uncertainties and assumptions about us. Our actual results~~meaning of operations may differ materially from the forward-looking statements as a result of, among other things, the success or failure of our clinical trials, the speed at which our clinical trials progress, the success of our competitors in developing products equal or superior to ours, the success of our collaborative relationships and the other reasons described under "Risk Factors." We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. In light of these risks, uncertainties and assumptions, the forward-looking events discussed in this prospectus might not occur. For these statements, we claim the protectionSection 27A of the ~~safe harbor for forward-looking statements contained in~~Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Exchange Act. ~~iii~~ ~~SUMMARY The following summary highlights information contained~~Some of the forward-looking statements can be identified by the use of forward-looking words including, but not limited to, “believes,” “expects,” “may,” “will,” “should,” “seeks,” “approximately,” “intends,” “plans,” “estimates” or “anticipates” 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 ~~other parts of this prospectus or incorporated by reference in this prospectus.~~the forward-looking statements. These factors include, but are not limited to:


	•	our anticipated business strategies;

	•	our ongoing and anticipated clinical trials;

	•	our intention to introduce new product candidates;

	•	our ability to conduct clinical trials and obtain regulatory approval of our product candidates;

	•	our relationships with collaborators;

	•	anticipated trends in our businesses; and

	•	future capital expenditures.

You should ~~read this summary together with~~not place undue reliance on any such forward-looking statements. Except to the ~~more detailed~~extent required by federal securities laws, we do not intend to update forward-looking information ~~elsewhere in this prospectus and in our financial~~or to release the results of any future revisions we may make to forward-looking statements ~~and accompanying notes and other information incorporated by reference in this prospectus.~~ to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.

Regeneron Pharmaceuticals, Inc. is a biopharmaceutical company that discovers, develops, and intends to commercialize ~~therapeutic drugs~~pharmaceutical products for the treatment of serious medical conditions. Our ~~product~~clinical and preclinical pipeline includes product candidates for the treatment of ~~obesity,~~cancer, diseases of the eye, rheumatoid arthritis and other inflammatory conditions, ~~cancer and related disorders,~~ 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 ~~any~~ profits from the commercialization of any of our product candidates.

Our clinical candidates, as of September 30, 2004, include the VEGF Trap, interleukin-1 Trap (IL-1 Trap), interleukin-4/interleukin-13 Trap (IL-4/13 Trap), and AXOKINE®. The 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. The 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. The 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 is a protein-based product candidate designed to act on the brain region regulating appetite and energy expenditure. AXOKINE is being developed for the treatment of obesity.

Our core business strategy is to combine our strong foundation in ~~science~~basic scientific research and discovery-enabling technology with ~~state-of-the-art~~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 ~~unmet~~serious medical ~~needs. Our~~conditions. We believe that our ability to develop product candidates ~~results from~~is enhanced by the application of our technology platforms. ~~In contrast to basic genomics approaches which attempt to identify every gene in a cell or genome, our technology~~These platforms are designed to discover specific genes of therapeutic interest for a particular disease or cell ~~type.~~type and validate targets through high-throughput production of mammalian models. We ~~will~~ 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 this prospectus.

We operate in an environment that involves a number of significant risks and uncertainties. We caution you to read the following risk factors, which have affected, and/or in the future could affect, our business, operating results, financial condition, and cash flows. The risks described below include forward-looking statements, and our actual results may differ substantially from those discussed in these forward-looking statements. Additional risks and uncertainties not currently known to us or that we currently deem immaterial may also impair our business operations. Furthermore, additional risks and uncertainties are ~~a New York corporation organized~~included in our most recent annual and quarterly report filings with the SEC and other documents incorporated herein by reference and should be considered by our investors.

~~Risks Related to Our Financial Results and Need for Additional Financing~~

From inception on January 8, ~~1988. Our executive offices~~1988 through September 30, 2004, we had a cumulative loss of $492.6 million. If we continue to incur operating losses and fail to become a profitable company, we may be unable to continue our operations. We have no products that are available for sale and do not know when we will have products available for sale, if ever. In the absence of revenue from the sale of products or other sources, the amount, timing, nature or source of which cannot be predicted, our losses will continue as we conduct our research and development activities. We currently receive contract manufacturing revenue from our agreement with Merck & Co., Inc. and contract research and development revenue from our agreements with The Procter & Gamble Company and Serono International S.A. All three of these agreements are scheduled to expire, unless extended by mutual agreement, before the end of 2005. We can provide no assurance that all or any of these agreements will be extended. Failure to extend these agreements may negatively impact our business, financial condition or results of operations.

We will need to expend substantial resources for research and development, including costs associated with clinical testing of our product candidates. We believe our existing capital resources will enable us to meet operating needs through at ~~777 Old Saw Mill River Road, Tarrytown, New York 10591-6707~~least the end of 2006; however, our projected revenue may decrease or our expenses may increase and that would lead to our ~~telephone number is (914) 347-7000. 1~~ ~~THE OFFERING The following is~~capital being consumed significantly before such time. We will likely require additional financing in the future and we may not be able to raise such additional funds. If we are able to obtain additional financing through the sale of equity or convertible debt securities, such sales may be dilutive to our shareholders. Debt financing arrangements may require us to pledge certain assets or enter into covenants that would restrict certain business activities or our ability to incur further indebtedness and may contain other terms that are not favorable to our shareholders. If we are unable to raise sufficient funds to complete the development of our product candidates, we may face delay, reduction or elimination of our research and development programs or preclinical or clinical trials, in which case our business, financial condition or results of operations may be materially harmed.

We have a brief summary of the terms of the notes. For a more complete description of the notes, see "Description of the Notes" in this prospectus. Issuer........................ Regeneron Pharmaceuticals, Inc. Notes offered................. $200,000,000 aggregate principalsignificant amount of 5 1/2% Convertible Senior Subordinated Notes due 2008. Maturity...................... October 17, 2008. Interest...................... 5 1/2% per annum on the principal amount, payable semi-annually on April 17convertible debt and October 17 of each year, beginning April 17, 2002. Conversion rights............. The notes are convertible at the option of the holder at any time on or priorsemi-annual interest payment obligations. This debt, unless converted to ~~maturity into~~ shares of our common stock, ~~at a conversion price of approximately $30.25 per share, which is equal~~will mature in October 2008. We may be unable to ~~a conversion rate of 33.0565 shares per $1,000 principal~~generate sufficient cash flow or otherwise obtain funds necessary to make required payments on our debt. Even if we are able to meet our debt service obligations, the amount of ~~notes. The conversion price is subject~~debt we already have could hurt our ability to ~~adjustment. Security...................... We have purchased and pledged~~obtain any necessary financing in the future for working capital, capital expenditures, debt service requirements or other purposes. In addition, our debt obligations could require us to ~~the trustee under the indenture, as security for the notes and for the exclusive benefit~~use a substantial portion of the holders of the notes, $31.6 million of U.S. government securities, which will be sufficient upon receipt of scheduledcash to pay principal and interest ~~payments thereon,~~on our debt, instead of applying those funds to provide for the payment in full of the first six scheduled interest payments on the notes when due. The notes will not otherwise be secured. Provisional Redemption........ We may redeem the notes, in whole or in part, at any time before October 17, 2004 at a redemption price equal to $1,000 per $1,000 principal amount of notes to be redeemed, plus accrued and unpaid interest, if any, to the date of the provisional redemption if (i) the closing price of our common stock has exceeded 150% of the conversion price then in effect for at least 20 trading days within a period of 30 consecutive trading days ending on the trading day before the date on which we mail the provisional redemption notice and (ii) during the period that we are obligated under the registration rights agreement to keep this shelf registration statement effective,other purposes, such shelf registration statement covering resales of the notes and the common stock issuable upon conversion of the notes is effective and available for use as of, and including, the date on which we mail the provisional redemption notice through and including the provisional redemption date. Upon any provisional redemption, we will make an additional "make-whole" payment in cash with respect to the notes called for redemption in an amount equal to $165 per $1,000 principal amount of notes, less the amount of any interest actually paid on the notes before the provisional redemption date. We will be obligated to make this additional payment on all notes called for provisional redemption, including any notes converted after the provisional redemption notice date and before the provisional redemption date. 2 Optional redemption........... We may redeem all or a portion of the notes on or after October 17, 2004 at $1,000 per $1,000 principal amount of the notes, plus accrued and unpaid interest, if any, if the closing price of our common stock has exceeded 140% of the conversion price then in effect for at least 20 trading days within a period of 30 consecutive trading days ending on the trading day before the date on which we mail the optional redemption notice. Repurchase Upon Change of Control....................... Holders of the notes may require us to repurchase all or part of the holder's notes at 100% of their principal amount, plus accrued and unpaid interest, if any, in certain circumstances involving a change of control. The repurchase price is payable: - in cash; or - at our option, subject to the satisfaction of certain conditions, in shares of our common stock. The number of shares of common stock will equal the repurchase price divided by 95% of the average closing sales prices of our common stock for the five-trading-day period ending on the third business day prior to the repurchase date. Ranking....................... The notes are our unsecured (except to the extent described under "Description of the Notes -- Security") senior subordinated obligations. They rank junior in right of payment to all of our existing and future Senior Indebtedness (as defined herein), and rank equally with all of our existing and future senior subordinated indebtedness. We had approximately $21.8 million of Senior Indebtedness outstanding as of December 31, 2001. Form and denomination......... The notes were issued in fully registered form. The notes are represented by one or more global notes, deposited with the trustee as a custodian for the Depository Trust Company ("DTC") and registered in the name of Cede & Co., DTC's nominee. Beneficial interests in the global notes are shown on, and any transfers are effected only through, records maintained by DTC and its participants. Use of proceeds............... We will not receive any of the proceeds from the sale by any selling securityholder of the notes or shares of common stock offered under this prospectus. Trading....................... The notes sold to qualified institutional buyers are eligible for trading in the PORTAL market; however, the notes resold pursuant to this prospectus will no longer trade on the PORTAL market. We do not intend to list the notes on any national securities exchange or the Nasdaq National Market. Nasdaq symbol for our common stock......................... Our common stock is quoted on the Nasdaq National Market under the symbol "REGN." Common Shares................. As of December 31, 2001, there were 41,264,280 shares of common stock and 2,562,689 shares of Class A stock issued and outstanding, our Class A stock together with our common stock 3 are our common shares. Holders of our Class A stock are entitled to ten votes per share and the holders of our common stock are entitled to one vote per share. The outstanding shares of Class A stock represented approximately 38.3% of the combined voting power of our outstanding common shares, on that date. The holders of our Class A stock and the holders of our common stock have identical rights, except with respect to voting and conversion rights and restrictions on transferability. Risk Factors.................. See "Risk Factors" and other information in this prospectus for a discussion of factors you should carefully consider before deciding to invest in the notes. 4 RISK FACTORS You should carefully consider the following risk factors together with the other information contained in or incorporated into this prospectus before you decide to buy our notes. If any of these risks actually occurs, our business, financial condition, operating results or cash flows could be materially adversely affected. This could cause the trading price of the notes or our common stock to decline and you may lose part or all of your investment. RISKS RELATED TO OUR BUSINESS, INDUSTRY AND STRATEGY Our research and development, ~~programs may be unsuccessful~~working capital, and ~~may not lead~~capital expenditures.

~~Risks Related to ~~the development~~Development of ~~any commercially successful products.~~ Our Product Candidates~~

Only a small minority of all research and development programs ultimately result in commercially successful drugs. We ~~are attempting to develop drugs~~have never developed a drug that has been approved for ~~human therapeutic uses. In order to begin the development process, we need to identify potential product candidates. Although we currently have several product candidates, our research~~marketing and development activities may not successfully identify new product candidates. Our ability to commercialize the product candidates we do identify depends on completing clinical trials which demonstrate their safety and efficacy to the satisfaction of the United States Food and Drug Administration (FDA) and applicable foreign regulatory authorities. Clinical trials are a multi-step process as the product candidate is tested in larger populations, and a product candidate could fail at any step. Each stage of clinical development is more costly than the prior stagesale, and we may ~~expend substantial resources on a product candidate~~never succeed in developing an approved drug. Even if clinical trials demonstrate safety and ~~then determine it cannot be successfully commercialized. For example, following a review~~effectiveness of the clinical trial data, we and Amgen discontinued the development of Brain-Derived Neurotrophic Factor (BDNF) for the treatment of amyotrophic lateral sclerosis in January 2001. We may never obtain regulatory approval for any of our product ~~candidates. Even if the safety and efficacy of our product~~ candidates ~~are demonstrated in clinical trials~~for a specific disease and the necessary regulatory approvals are obtained, the commercial success of any of our product candidates will depend ~~on our ability to successfully develop, manufacture, and market our product candidates and~~ upon their acceptance by patients, the medical community, and third-party ~~payors.~~payors and on our and our partners’ ability to successfully manufacture and commercialize our product candidates. Our product candidates are delivered either by intravenous or subcutaneous injections, which are generally less well received by patients than tablet or capsule delivery. If our products are not successfully commercialized, we will not be able to recover the significant investment we have made in developing such products and our business would be severely harmed.

We may be required to suspend, repeat, or terminate our clinical trials, which could have a material adverse effect on our business. In order to obtain regulatory approval for the commercializationmust conduct extensive testing of our product candidates before we ~~will be required~~can obtain regulatory approval to ~~complete extensive~~market and sell them. We need to conduct both preclinical animal testing and human clinical trials. Conducting these trials ~~in humans~~is a lengthy, time-consuming, and expensive process. These tests and trials may not achieve favorable results for many reasons, including, among others, failure of the product candidate to demonstrate safety or efficacy, the development of serious or life-threatening adverse events (or side effects) caused by or connected with exposure to the product candidate, difficulty in enrolling and ~~efficacy~~maintaining subjects in the clinical trial, lack of sufficient supplies of the product candidates. We have limited experience in conducting clinical trials. A clinical trial may be suspended or terminated by us or the FDA, or otherwise fail, for a number of reasons, including: - the product candidate, may cause unforeseen adverse sides effects, including immune reactions; - the time required to determine whether the product candidate is effective may be longer than expected; - the product candidate may not appear to be more effective than current available therapies; -and the failure ~~to enroll a sufficient number~~ of ~~patients meeting eligibility requirements; - the~~ clinical investigators, trial monitors and other consultants, or trial subjects ~~may fail~~ to comply with the trial plan or ~~protocol;~~protocol. A clinical trial may also fail because it did not include a sufficient number of patients to detect the endpoint being measured or -reach statistical significance. For example, the trials studying the maintenance of weight loss following short-term treatment regimens with AXOKINE did not enroll a sufficient number of patients to detect statistically significant differences between patients treated with AXOKINE and those taking placebo. These trials were designed before we had access to the data from the completed pivotal phase 3 AXOKINE trial, which demonstrated that the magnitude of the average difference in weight loss observed between all AXOKINE-treated subjects and those taking placebo was small.

We will need to reevaluate any drug candidate that does not test favorably and either conduct new trials, which are expensive and time consuming, or abandon the drug development program. Even if we obtain positive results from preclinical or clinical trials, we may not achieve the same success in future trials. Many companies in the biopharmaceutical industry, including us, have suffered significant setbacks in clinical trials, even after promising results have been obtained in earlier trials. The failure of clinical trials to ~~be able to supply sufficient quantities~~demonstrate safety and effectiveness for our desired indications could harm the development of the product candidate, ~~to complete~~and our business, financial condition, and results of operations may be materially harmed.

During the ~~trial. 5~~ ~~Success in preclinical and early~~conduct of clinical trials, ~~may~~patients report changes in their health, including illnesses, injuries, and discomforts, to their study doctor. Often, it is not ~~be predictive of~~possible to determine whether or not the ~~results in large-scale trials. Any failure or substantial delay in successfully completing~~drug candidate being studied caused these conditions. Various illnesses, injuries, and discomforts have been reported from time-to-time during clinical trials and obtaining regulatory approval for our product candidates could severely harm our business. We may not be successful in our attempt to broaden our product pipeline as it will require expertise and resources we do not currently have. We have expanded from our initial focus on degenerative neurologic diseases and broadened our product pipeline to include drug candidates for the treatment of other diseases. As our scientific efforts lead us in new directions into conditions or diseases outside of our areas of experience and expertise, we will require additional internal expertise or external collaborations in areas in which we currently do not have substantial resources and personnel. As we develop drug candidates independently, we will require additional resources that may be difficult to obtain. If we have to enter into collaboration arrangements with others, we may be required to relinquish rights to some of our technologies, product candidates, or products that we would otherwise pursue independently. We may not be able to acquire the necessary expertise internally or be able to enter into collaboration arrangements on acceptable terms to develop additional drug candidates. We have never generated sales or profits and expect to incur losses over the next several years. We have not received revenue from the commercialization of our product candidates. ~~We do not expect~~Although our current drug candidates appeared to receive any revenue from the commercialization of our product candidates for at least the next several years. We intend to continue to invest significantly in our product candidates. We have incurred losses in each year since inception of operations in 1988. As of September 30, 2001, we had an accumulated deficit of $271.3 million. We may never have an approved or commercially successful product or achieve significant revenues or profitable operations. If we fail to gain approval from the FDA to commercialize a product candidate, we may not be able to earn sufficient revenue to continue as a going concern. We currently receive revenue from third parties; if we do not receive these revenues, we may need to find alternative sources of funding for our research and development activities. To date, we have received revenues from (1) our licensees and collaborators for research and development efforts, (2) Merck & Co. Inc. and Sumitomo Pharmaceuticals Co., Ltd. for contract manufacturing, and (3) investment income. We may not continue to receive these revenues or the amount of these revenues may be dramatically reduced. In the absence of these revenues, we will have to obtain other sources of funding to continue to conduct our research and development activities. For example, in January 2001, Amgen-Regeneron Partners discontinued all clinical development of BDNF, which is licensed to Sumitomo Pharmaceuticals for development in Japan. As a result, we do not expect to receive further payments from Sumitomo Pharmaceuticals in connection with the licensing of BDNF. We recognized revenue from Sumitomo Pharmaceuticals of $0.2 million in the nine months ended September 30, 2001, $7.6 million in 2000, $0.1 million in 1999, and $8.8 million in 1998. We may require additional financing, which may be difficult to obtain and may dilute the ownership interest of shareholders. We have had negative cash flow from operations in each year since our inception. We expect that the funding requirements for our activities will remain substantial and could increase significantly if our development or clinical trial programs are successful or our research is expanded. For example, the costs of conducting our Phase III clinical program for AXOKINE, if successful, would likely exceed $75 million or more. We anticipate that the net proceeds from our sale on October 17, 2001 of $200 million aggregate principal amount of our 5 1/2% Convertible Senior Subordinated Notes due 2008, together with our cash, cash equivalents, and marketable securities of $268.0 million as of September 30, 2001, will be 6 sufficient for our working capital needs until 2003. However, we may need additional funding sooner due to a number of factors, including: - the speed with which some of our earlier stage developmental products move into later stage clinical development; - the identification of additional product candidates; - the identification of new indications for a potential product in later stage clinical trials; - the termination of any of our collaboration agreements; - the acquisition of technologies or product candidates; - the pursuit of new business opportunities; - the cost of developing a marketing or sales force; and - the cost of developing or defending our patents, patent applications, and other intellectual property rights. We have no established banking arrangements through which we can obtain short-term financing or a line of credit. We may seek additional funding through collaborative arrangements and public or private financing. Additional financing may not be available to us on acceptable terms or at all. If we are unable to obtain additional funding when needed, we may have to delay or scale back some of our programs or grant to third parties rights to development or other product rights. If we raise additional funds by issuing equity securities or equity-related securities, further dilution to our then existing shareholders may result. Undesirable and unintended side effects of AXOKINE may terminate, interrupt or delay clinical studies and could ultimately prevent or limit its commercial use. Various side-effects have been reported during the clinical trials of AXOKINE, our only product candidate that has completed Phase II trials. During the Phase I study that was conducted in 1999, incidents of nausea, vomiting, and recurrence of herpes simplex virus, or HSV, were reported by patients taking AXOKINE. Recurrence of HSV was also reported in previous clinical studies of CNTF, AXOKINE's parent molecule. In addition, in the Phase I study, one patient who was HSV positive prior to treatment and had been previously diagnosed with Bell's palsy, had a recurrence of Bell's palsy approximately two weeks after the patient's last administration of AXOKINE. In the recently completed Phase II study of AXOKINE, reported side effects included injection site reactions, nausea, cough, and vomiting. Although AXOKINE was generally well tolerated in ~~the recently completed Phase II trial,~~clinical trials conducted to date, it is possible ~~that~~ as we test ~~AXOKINE~~any of them in ~~a large~~larger, longer, and ~~extended Phase III trial, these side effects,~~more extensive clinical programs, illnesses, injuries, and discomforts that were observed in earlier trials, as well as ~~side effects~~conditions that did not occur or went undetected in smaller previous trials, will be reported by patients. If additional clinical experience indicates that any of our product candidates has many side effects or

~~causes serious or life-threatening side effects, the development of the product candidate may fail or be delayed, which would severely harm our business.~~

Our VEGF Trap is being studied for the potential treatment of certain types of cancer and diseases of the eye. There are many potential safety concerns associated with significant blockade of vascular endothelial growth factor, or VEGF. These safety concerns may limit our ability to successfully develop the VEGF Trap.

Genentech, Inc. and Eyetech Pharmaceuticals, Inc. are developing VEGF inhibiting molecules for certain diseases of the eye that will be delivered by direct administration to the eye. We plan to study the VEGF Trap for the potential treatment of certain diseases of the eye through intravitreal injections in the eye and are conducting trials of the VEGF Trap utilizing systemic administration through intravenous infusions or subcutaneous injections. Although we believe that there are potential clinical advantages to systemic administration over injections directly in the eye (including patient comfort and acceptance), there are unique potential risks to patients associated with the systemic blockade of VEGF by intravenous infusions or subcutaneous injections that could limit or end the VEGF Trap development program. These risks, based on the clinical and preclinical experience of systemically delivered VEGF inhibitors, include bleeding, hypertension, and proteinuria. Certain of these serious side effects and other serious side effects have been reported in our VEGF Trap studies. In addition, patients given infusions of any protein, including the VEGF Trap, may develop severe hypersensitivity reactions, referred to as infusion reactions. There may be additional complications or side effects that could harm the development of the VEGF Trap for either the treatment of cancer or diseases of the eye.

In addition to the safety, efficacy, manufacturing, and regulatory hurdles faced by our product candidates, the administration of recombinant proteins frequently causes an immune response, resulting in the creation of antibodies against the therapeutic protein. The antibodies can have no effect or can totally neutralize the effectiveness of the protein, or require that higher doses be used to obtain a therapeutic effect. In some cases, the antibody can cross react with the patient’s own proteins, resulting in an “auto-immune” type disease. Whether antibodies will be created can often not be predicted from preclinical or clinical experiments, and their appearance is often delayed, so that there can be no assurance that neutralizing antibodies will not be created at a later date — in some cases even after pivotal clinical trials have been completed. Approximately two-thirds of the subjects who received AXOKINE in the completed phase 3 study developed neutralizing antibodies. In addition, subjects who received the IL-1 Trap in clinical trials have developed antibodies. It is possible that as we test the VEGF Trap in different patient populations and larger clinical trials, subjects given the VEGF Trap will ~~become apparent.~~develop antibodies to the product candidate.

In March 2003, we reported data from the 12-month treatment period of our initial phase 3 pivotal trial of AXOKINE. Although the phase 3 study met its primary endpoints and individuals achieved a medically meaningful weight loss, the average weight loss was small and limited by the development of antibodies.

In October 2003, we reported results from the first phase 2 trial of our IL-1 Trap in rheumatoid arthritis. We ~~face substantial competition~~plan to conduct a phase 2b study of the IL-1 Trap in a larger patient population, testing higher doses than were tested in the previous phase 2 trial for a longer period of time. We plan to study higher doses of the IL-1 Trap through subcutaneous injections and intravenous delivery. However, higher doses may not lead to better results than were demonstrated in the previous phase 2 trial. In addition, safety or tolerability concerns may arise which limit our ability to deliver higher doses of the IL-1 Trap to patients. The dose levels that will be tested are substantially higher than the dose levels of other biological therapeutics currently approved for the treatment of rheumatoid arthritis. Either approach may affect the safety and/or tolerability of the IL-1 Trap, which may limit its commercial potential if the product candidate is ever approved for marketing and sale.

We cannot sell or market products without regulatory approval. If we do not obtain and maintain regulatory approval for our product candidates, the value of our company and our results of operations will be harmed. In the United States, we must obtain and maintain approval from the United States Food and Drug Administration (FDA) for each drug we intend to sell. Obtaining FDA approval is typically a lengthy and expensive process, and approval is highly uncertain. Foreign governments also regulate drugs distributed in their country and approval in any country is likely to be a lengthy and expensive process, and approval is highly uncertain. None of our product candidates has ever received regulatory approval to be marketed and sold in the United States or any other country. We may never receive regulatory approval for any of our product candidates.

The testing, manufacturing, marketing, and sale of drugs for use in people expose us to product liability risk. We are currently involved in a product liability lawsuit brought by a subject who participated in a clinical trial of one of our drug candidates. Any informed consent or waivers obtained from people who sign up for our clinical trials may not protect us from liability or the cost of litigation. Our product liability insurance may not cover all potential liabilities or may not completely cover any liability arising from any such litigation. Moreover, we may not have access to liability insurance or be able to maintain our insurance on acceptable terms.

In May 2003, securities class action lawsuits were commenced against us and certain of our officers and directors in the United States District Court for the Southern District of New York. A consolidated amended class action complaint was filed in October 2003. The complaint, which purports to be brought on behalf of a class consisting of investors in our publicly traded securities between March 28, 2000 and March 30, 2003, alleges that the defendants misstated or omitted material information concerning the safety and efficacy of AXOKINE, in violation of Sections 10(b) and 20(a) of the Securities and Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. Damages are sought in an unspecified amount. We have not established a reserve for damages because we do not believe that a loss is probable. However, if the outcome of the litigation is adverse to us, we could be subject to significant liability, which could exceed our insurance coverage.

As a biopharmaceutical company with significant manufacturing operations, we are subject to extensive environmental, health, and safety laws and regulations, including those governing the use of hazardous materials. Our research and development and manufacturing activities involve the controlled use of chemicals, viruses, radioactive compounds, and other hazardous materials. The cost of compliance with environmental, health, and safety regulations is substantial. If an accident involving these materials or an environmental discharge were to occur, we could be held liable for any resulting damages, or face regulatory actions, which could exceed our resources or insurance coverage.

We relied heavily on Novartis to provide their expertise, resources, funding, manufacturing capacity, clinical expertise, and commercial infrastructure to support the IL-1 Trap program. Novartis’ decision to withdraw from participating in the development and commercialization of the IL-1 Trap may delay or disrupt the IL-1 Trap program. We do not have the resources and skills to replace those of Novartis, which could result in ~~others discovering,~~significant delays in the development and potential commercialization of the IL-1 Trap. In addition, we will have to fund the development and commercialization of the IL-1 Trap without Novartis’ long-term commitment, which will require substantially greater expenditures on our part.

We rely heavily on Aventis to assist with the development of the VEGF Trap. If the VEGF Trap program continues, we will rely on Aventis to assist with funding the VEGF Trap program, providing commercial manufacturing capacity, enrolling and monitoring clinical trials, obtaining regulatory approval, particularly outside the United States, and providing sales and marketing support. While we cannot assure you that the VEGF Trap will ever be successfully developed and commercialized, if Aventis does not perform its obligations in a timely manner, or at all, our ability to develop, manufacture, and commercialize the VEGF Trap will be significantly adversely affected. Aventis has the right to terminate its collaboration agreement with us at any time. If Aventis were to terminate its collaboration agreement with us, we might not have the resources or skills to replace those of our partner, which could cause significant delays in the development and/or manufacture of the VEGF Trap and result in substantial additional costs to us. We have no sales, marketing or distribution capabilities and would have to develop or outsource these capabilities. Termination of the Aventis collaboration agreement would create new and additional risks to the successful development of the VEGF Trap.

Sanofi-Synthelabo recently acquired Aventis, forming the sanofi-aventis Group. At present, it is unclear what impact, if any, this business combination will have on the VEGF Trap collaboration, including the possibility of a termination of the collaboration agreement and a delay in, or disruption to, the VEGF Trap development program.

We depend upon third-party collaborators, including Aventis and service providers such as clinical research organizations, outside testing laboratories, clinical investigator sites, and third party manufacturers and product packagers and labelers, to assist us in the development of our product candidates. If any of our existing collaborators or service providers breaches or terminates its agreement with us or does not perform its development or manufacturing services under an agreement in a timely manner or at all, we would experience additional costs, delays, and difficulties in the development or ultimate commercialization of our product candidates.

Before approving a new drug or biologic product, the FDA requires that the facilities at which the product will be manufactured be in compliance with current good manufacturing practices, or cGMP requirements. Manufacturing product candidates in compliance with these regulatory requirements is complex, time-

consuming, and expensive. To be successful, our products must be manufactured for development, following approval, in commercial quantities, in compliance with regulatory requirements, and at competitive costs. If we or any of our product collaborators or third-party manufacturers, fillers or labelers are unable to maintain regulatory compliance, the FDA can impose regulatory sanctions, including, among other things, refusal to approve a pending application for a new drug or biologic product, or revocation of a pre-existing approval. As a result, our business, financial condition, and results of operations may be materially harmed.

Our manufacturing facility is likely to be inadequate to produce sufficient quantities of product for commercial sale. We intend to rely on our corporate collaborators, as well as contract manufacturers, to produce the large quantities of drug material needed for commercialization of our products. We rely entirely on third party manufacturers for filling and finishing services. We will have to depend on these manufacturers to deliver material on a timely basis and to comply with regulatory requirements. If we are unable to supply sufficient material on acceptable terms, or if we should encounter delays or difficulties in our relationships with our corporate collaborators or contract manufacturers, our business, financial condition, and results of operations may be materially harmed.

We may expand our own manufacturing capacity to support commercial production of active pharmaceutical ingredients, or API, for our product candidates. This will require substantial additional funds, and we will need to hire and train significant numbers of employees and managerial personnel to staff our facility. Start-up costs can be large and scale-up entails significant risks related to process development and manufacturing yields. We may be unable to develop manufacturing facilities that are sufficient to produce drug material for clinical trials or commercial use. In addition, we may be unable to secure adequate filling and finishing services to support our products. As a result, our business, financial condition, and results of operations may be materially harmed.

We may be unable to obtain key raw materials and supplies for the manufacture of our product candidates. In addition, we may face difficulties in developing or ~~commercializing~~acquiring production technology and managerial personnel to manufacture sufficient quantities of our product candidates at reasonable costs and in compliance with applicable quality assurance and environmental regulations and governmental permitting requirements.

We maintain an 8,000 square foot manufacturing facility in Tarrytown, New York and have large-scale manufacturing operations in Rensselaer, New York. Under a long-term manufacturing agreement with Merck, which expires in October 2005 unless extended by mutual agreement, we produce an intermediate for a Merck pediatric vaccine at our facility in Rensselaer, New York. We also use our facilities to produce API for our own clinical and preclinical candidates. If we no longer use our facilities to manufacture the Merck intermediate or clinical candidates are discontinued, we would have to absorb overhead costs and inefficiencies.

Certain raw materials necessary for manufacturing and formulation of our product candidates are provided by single-source unaffiliated third-party suppliers. We would be unable to obtain these raw materials for an indeterminate period of time if these third-party single-source suppliers were to cease or interrupt production or otherwise fail to supply these materials or products ~~before~~to us for any reason, including due to regulatory requirements or ~~more~~action, due to adverse financial developments at or affecting the supplier or due to labor shortages or disputes. This, in turn, could materially and adversely affect our ability to manufacture our product candidates for use in clinical trials, which could materially and adversely affect our operating results.

Also, certain of the raw materials required in the manufacturing and the formulation of our clinical candidates may be derived from biological sources, including mammalian tissues, bovine serum, and human serum albumin. There are certain European regulatory restrictions on using these biological source materials.

~~If we are required to substitute these sources to comply with European regulatory requirements, our clinical development activities may be delayed or interrupted.~~

We have no sales or distribution personnel or capabilities and have only a small staff with marketing capabilities. If we are unable to obtain those capabilities, either by developing our own organizations or entering into agreements with service providers, we will not be able to successfully sell any products that we may bring to market in the future. In that event, we will not be able to generate significant revenue, even if our product candidates are approved. We cannot guarantee that we will be able to hire the qualified sales and marketing personnel we need or that we will be able to enter into marketing or distribution agreements with third-party providers on acceptable terms, if at all. Under the terms of our collaboration agreement with Aventis, we currently rely on Aventis for sales, marketing, and distribution of the VEGF Trap, should it be approved in the future by regulatory authorities for marketing. We will have to rely on a third party or devote significant resources to develop our own sales, marketing, and distribution capabilities for our other product candidates, and we may be unsuccessful in developing our own sales, marketing, and distribution organization.

Changes in product formulations and manufacturing processes may be required as product candidates progress in clinical development and are ultimately commercialized. If we are unable to develop suitable product formulations or manufacturing processes to support large scale clinical testing of our product candidates, including the VEGF Trap, IL-1 Trap, IL-4/13 Trap, and AXOKINE, we may be unable to supply necessary materials for our clinical trials, which would delay the development of our product candidates. Similarly, if we are unable to supply sufficient quantities of our product or develop product formulations suitable for commercial use, we will not be able to successfully commercialize our product candidates. For example, we are in the process of developing formulations that would allow delivery of higher doses of the IL-1 Trap to test in clinical trials. The dose levels that will be tested are substantially higher than the dose levels of other biological therapeutics currently approved for treatment of rheumatoid arthritis. Separate new formulations will be used for subcutaneous and intravenous administration of the higher dose therapeutic. If we ~~do.~~ are unable to develop or manufacture such a higher dose formulation that can be produced in a cost-effective manner, potential future IL-1 Trap sales and profitability may be limited.

There is substantial competition in the biotechnology and pharmaceutical industries from pharmaceutical, biotechnology, and chemical companies. Our competition includes Hoffmann-La Roche, Inc., Merck, Abbott Laboratories, Inc., Immunex Corporation, Amgen Inc. and others. Each have products under development or currently available for sale that address the same or similar medical conditions as some of our product candidates. Many of our competitors have substantially greater research, preclinical and clinical product development and manufacturing capabilities, and financial, marketing, and human resources than we do. Our smaller competitors may also ~~obtain a significant~~enhance their competitive ~~advantage~~position if they acquire or discover patentable inventions, form collaborative arrangements or merge with large pharmaceutical companies. Even if we achieve product commercialization, ~~one or more of~~ our competitors have achieved, and may continue to achieve, product commercialization ~~earlier than we do or obtain patent protection that can exclude us from~~before our products are approved for marketing and sale. Genentech has an approved VEGF antagonist on the market and many different pharmaceutical and biotechnology companies are working to develop competing VEGF antagonists, including Novartis, Eyetech Pharmaceuticals, and Pfizer Inc. Many of these molecules are farther along in development than the VEGF Trap and may offer competitive advantages over our molecule. The marketing approval for Genentech’s VEGF antagonist, Avastin^TM, may make it more difficult for us to enroll patients in clinical trials to support the VEGF Trap. This may delay or ~~adversely affect~~impair our ~~activities. Our~~ ability to ~~compete~~successfully develop and commercialize the VEGF Trap.

The markets for both rheumatoid arthritis and asthma are both very competitive. Several highly successful medicines are available for these diseases. Examples include the TNF-antagonists Enbrel® (a registered trademark of Amgen Inc.), Remicade® (a registered trademark of Centocor Inc.), and Humira® (a registered trademark of Abbott Laboratories) for rheumatoid arthritis, and the leukotriene-modifier Singulair® (a registered trademark of Merck), as well as various inexpensive corticosteroid medicines for asthma. The availability of highly effective FDA approved TNF-antagonists makes it more difficult to successfully develop the IL-1 Trap for the treatment of rheumatoid arthritis, since it will ~~depend on how fast we can develop 7~~ ~~safe and effective product candidates, obtain patent protection, complete~~be difficult to enroll patients with rheumatoid arthritis to participate in clinical ~~testing, obtain regulatory approval to commercialize our product candidates, and supply commercial quantities~~trials of the ~~product~~IL-1 Trap. This may delay or impair our ability to successfully develop the ~~market. If a competitor announces a successful clinical study involving a product that~~drug candidate. In addition, even if the IL-1 Trap is ever approved for sale, it will be difficult for our drug to compete against these FDA approved TNF-antagonists because doctors and patients will have significant experience using these effective medicines. Moreover, these approved therapeutics may beoffer competitive ~~with one of our product candidates or an approval by a regulatory agency to market a competing product, such announcement may have a material adverse effect on our operations, or future prospects,~~advantages over the price of our common stock and the notes. We also compete with academic institutions, governmental agencies, and other public or private research organizations, which conduct research, seek patent protection and establish collaborative arrangements for the development and marketing of products that would provide royalties for use of their technology. These institutions are becoming more active in seeking patent protection and licensing arrangements to collect royalties for use of the technology that they have developed. Products developed in this manner may compete directly with products we develop. We also compete with others in acquiring technology from such institutions, agencies, and organizations. Collaborative efforts with our academic and corporate partners may fail or be terminated, resulting in significant delays and substantial increases in our costs for research, development, and commercialization of some of our product candidates. We are party to various arrangements with academic and corporate partners and others. Our collaborators may also be our competitors,IL-1 Trap, such as ~~Amgen.~~requiring fewer injections. In addition, there are both small molecules and antibodies in development by third parties that are designed to block the synthesis of interleukin-1 or inhibit the signaling of interleukin-1. These drug candidates could offer competitive advantages over the IL-1 Trap. The successful development of ~~product candidates covered by~~ these ~~arrangements depends upon these outside parties fully performing their contractual responsibilities. If any of~~competing molecules could delay or impair our ~~collaborators breaches, or terminates its agreement with us or otherwise fails~~ability to conduct its collaborative activities in a timely manner consistent with the applicable contractual terms, the development or commercialization of the product candidate or research program under such collaborative arrangement may be delayed. If that is the case, we may be required to undertake unforeseen additional responsibilities or to devote unforeseen additional funds or other resources to such development or commercialization, or such development or commercialization could be terminated. For example, our collaboration agreement with Procter & Gamble has an "opt-out" provision whereby a party may decline to participate further in a research or product development program. In such cases, the opting-out party will generally not have any further funding obligation and will not have any rights to the product or program in question (but may be entitled to a royalty on any product sales). If Procter & Gamble were to opt out of a product development program, and we were not to find a new partner, we would bear the full cost of the program which may be substantial. In addition, disagreements between collaborators and us could lead to delays in the collaborative research, development, or commercialization of certain products or could require or result in formal legal process or arbitration for resolution. These consequences could be time-consuming and expensive and could have material adverse effects on us. We may seek additional collaborative arrangements tosuccessfully develop and commercialize the IL-1 Trap.

There is also substantial competition in the discovery and development of treatments for obesity, as well as established, cost-effective, and emerging surgical, prescription, and over-the-counter treatments for the disease that may offer competitive advantages over AXOKINE. AXOKINE is available only in injectable form, while the currently available marketed medicines for the treatment of obesity, and a late-stage product candidate in development by sanofi-aventis Group, are delivered in pill form, which is generally favored over injectable medicines. Therefore, even if AXOKINE is approved for sale, the fact that it must be delivered by injection may severely limit its market acceptance among patients and physicians.

Sales of biopharmaceutical products largely depend on the reimbursement of patients’ medical expenses by government health care programs and private health insurers. Without the financial support of the governments or third-party payors, the market for any biopharmaceutical product will be limited. These third-party payors increasingly challenge the price and examine the cost-effectiveness of products and services. Significant uncertainty exists as to the reimbursement status of any new therapeutic, particularly if there exist lower-cost standards of care. Third-party payors may not reimburse sales of our products, which would harm our business.

We are highly dependent on our executive officers. If we are not able to retain any of these persons or our Chairman, our business may suffer. In particular, we depend on the services of Roy Vagelos, M.D., the Chairman of our Board of Directors, Leonard Schleifer, M.D., Ph.D., our President and Chief Executive Officer, and George D. Yancopoulos, M.D., Ph.D., our Executive Vice President, Chief Scientific Officer and President, Regeneron Research Laboratories. There is intense competition in the ~~future.~~biotechnology industry for qualified scientists and managerial personnel in the development, manufacture, and commercialization of drugs. We may not be able to ~~negotiate collaborative arrangements on favorable terms~~continue to attract and retain the qualified personnel necessary for developing our business.

Our business requires using sensitive and proprietary technology and other information that we protect as trade secrets. We seek to prevent improper disclosure of these ~~collaborative arrangements~~trade secrets through confidentiality agreements. If our trade secrets are improperly exposed, either by our own employees or our collaborators, it would help our competitors and adversely affect our business. We will be able to protect our proprietary rights from unauthorized use by third parties only to the extent that our rights are covered by valid and enforceable patents or are effectively maintained as trade secrets. The patent position of biotechnology companies involves complex legal and factual questions and, therefore, enforceability cannot be predicted with certainty. Our patents may be challenged, invalidated or circumvented. Patent applications filed outside the United States may be challenged by third parties who file an opposition. Such opposition proceedings are increasingly common in the European Union and are costly to defend. We have patent applications that are being opposed and it is likely that we will need to defend additional patent applications in the future. Our patent rights may not provide us with a proprietary position or competitive advantages against competitors. Furthermore, even if the outcome is favorable to us, the enforcement of our intellectual property rights can be successful. In addition, our collaborative partners may pursue alternative technologies or develop alternative compounds independently or in collaboration with others as a means of developing treatments for the diseases targeted by their collaborative programs with us. If we cannot successfully manufacture our product candidates in an efficient manner,expensive and time consuming.

Our commercial success depends significantly on our ability to conduct clinical trials and commercialize our product candidates would be impaired. Our ability to conduct timely preclinical and clinical research and development programs, obtain regulatory approval, commercialize our product candidates and fulfill our contract manufacturing obligations to others will depend, in part, upon our ability to manufacture our products, either directly or through third parties, in accordance with FDAoperate without infringing the patents and other ~~regulatory requirements. 8~~ Weproprietary rights of third parties. Other parties may ~~not be able~~allege that they have blocking patents to ~~manufacture~~our Trap products ~~successfully~~in clinical development, either because they claim to hold proprietary rights to fusion proteins or ~~in a cost-effective manner at our facilities. We may also have difficulties obtaining~~proprietary rights to components of the ~~raw materials and supplies necessary to manufacture our product candidates~~Trap or the ~~products we manufacture for others. If we~~way it is manufactured. We are ~~unable~~aware of certain United States and foreign patents relating to ~~use our own manufacturing facilities or to contract with a third-party to manufacture our products on acceptable terms, we may not be able to conduct certain future preclinical~~particular IL-4 and ~~clinical testing or to supply commercial quantities~~IL-13 receptors. Our IL-4/13 Trap includes portions of ~~our product candidates. Our dependence upon third parties for~~ the ~~manufacture of some of our products~~IL-4 and ~~related therapies may adversely affect our profit margins and our ability to develop and deliver products on a timely and competitive basis. For example,~~IL-13 receptors. In addition, we are aware of ~~only one supplier of the reagent necessary~~a broad patent held by Genentech relating to produce a pegylated formulation of AXOKINE, which is substantially longer acting than unmodified AXOKINE in preclinical studies. Any problems with the supply of reagent from this vendor could result in the delay or interruption in the development of any pegylated form of AXOKINE. In addition, if our manufacturing facilities failproteins fused to ~~comply with FDA and other regulatory requirements,~~certain immunoglobulin domains. Our Trap product candidates include proteins fused to immunoglobulin domains. Although we will be required to suspend manufacturing. This will have a material adverse effect on our financial condition, results of operations, and cash flow. Since we have no sales and marketing experience or infrastructure, we may have to engage third parties to market our products or develop this experience and infrastructure internally which would be time consuming and expensive. We have no internal sales, marketing, and distribution experience or infrastructure and may have to rely significantly on arrangements with third parties in order to perform these functions. If we choose to depend on third parties for the marketing and sale of our products, the cost of using such third parties may adversely affect our profit margins. If we decide to perform sales, marketing, and distribution functions ourselves we would face a number of additional risks, including: - we maydo not be able to attract and build a significant marketing or sales force; - the significant cost of establishing a marketing or sales force may not be justifiable in light of any product revenues; and - our direct sales and marketing efforts may not be successful. We may not be able to attract or retain qualified scientific and management personnel, including our key personnel, on acceptable terms. We may not be able to retain our key personnel, in particular (1) our Chairman, P. Roy Vagelos, M.D., (2) our President and Chief Executive Officer, Leonard S. Schleifer, M.D., Ph.D., and (3) our Chief Scientific Officer, George D. Yancopoulos, M.D., Ph.D., on termsbelieve that are acceptable to us. In addition, our anticipated growth and expansion into new areas requiring additional expertise will place increased demands on our resources and require additional management personnel and the development of additional expertise by existing management personnel. Attracting and retaining qualified personnel is critical to our success. Many of our competitors are established pharmaceutical and biotechnology companies that may have greater success in recruiting skilled scientific workers from the limited pool of available talent. The failure to attract and retain management and scientific personnel could have a material adverse effect on our research and development work and on the operation of our business. We could be exposed to significant liability claims and our insurance coverage may not be adequate to cover these claims. The testing, manufacturing, and marketing of human pharmaceutical products entails significant inherent risks. Their use in clinical trials and their sale may expose us to substantial liability claims. These claims might be made directly by patients, consumers, pharmaceutical companies, or others selling the products. We are insured by product liability insurance policies, the purpose of which is to cover certain claims that could arise during the clinical trials of our product candidates. We may not be able to 9 maintain or renew the insurance we have or obtain additional coverage. If our insurance coverage is insufficient, a significant product liability claim or recall would have a material adverse effect on us. If we were required to register as an investment company we would become subject to substantial regulation and our business adversely affected. The Investment Company Act of 1940, as amended (the "1940 Act"), requires the registration of, and imposes various substantive restrictions on, certain companies that engage primarily, or propose to engage primarily, in the business of investing, reinvesting or trading in securities, or fail certain statistical tests regarding the composition of assets and sources of income and are not primarily engaged in businesses other than investing, holding, owning, or trading securities. We presently satisfy these statistical tests and intend to remain primarily engaged in businesses other than investing, reinvesting, owning, holding, or trading securities. In addition, we are ~~relying on an SEC position that biotechnology companies such as our company are not investment companies required to register under~~infringing valid and enforceable third party patents, the ~~1940 Act. We expect to continue to be able to avoid registration requirements~~holders of the 1940 Act. If we were required to register as an investment company under the 1940 Act, we would become subject to substantial regulations with respect to our capital structure, management, operations, transactions with affiliates described in the 1940 Act and other matters. Application of the provisions of the 1940 Act would have a material adverse effect on our business. RISKS RELATED TO INTELLECTUAL PROPERTY We may not be able to obtain and adequately protect our intellectual property rights or avoid infringing the rights of others. Our success depends to a large part upon our own, our licensors' and our collaborators' ability to obtain and defend patent rights and other intellectual property rights that are important to the commercialization of our product candidates. We or our licensors or collaborators have filed patent applications on products and processes relating to AXOKINE, Cytokine Traps, VEGF Trap, Angiopoietins, and NT-3, as well as other technologies and inventions in the United States and in certain foreign countries. Although we have obtained a number of U.S. patents, patent applications owned or licensed by us may not result in patents being issued. Moreover, these patents may ~~not afford~~sue us ~~protection against competitors with similar technology~~for infringement and a court may find that we are infringing one or ~~products. Parts of~~more validly issued patents, which may materially harm our ~~technology, techniques, and product candidates may conflict with patents owned by or granted to others.~~business.

Any patent holders could sue us for damages and seek to prevent us from manufacturing, selling or developing our ~~product candidates.~~drug candidates, and a court may find that we are infringing validly issued patents of third parties. In ~~September 2000, Immunex Corporation filed a request with~~ the ~~European Patent Office seeking~~event that the ~~declaration~~manufacture, use or sale of ~~an Opposition regarding the scope~~any of our ~~European patent relating to Cytokine Traps. This is a legal challenge to~~clinical candidates infringes on the ~~validity and scope~~patents or violates other proprietary rights of our patent. Although we plan to defend the patent diligently, the scope of the patent may be adversely affected following the outcome of the Opposition. Uncertainties resulting from the litigation and continuation of patent litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace. Any patent litigation or other proceeding even if resolved in our favor, absorbs significant financial resources and management time. Some of our competitors may be able to sustain these costs more effectively than we can because of their substantially greater financial and managerial resources. If a patent litigation or other intellectual property proceeding is resolved unfavorably to us,third parties, we may be ~~enjoined~~prevented from pursuing product development, manufacturing, ~~or selling~~and commercialization of our ~~products~~drugs and ~~services without~~may be required to pay costly damages. Such a ~~license from the other party~~result may materially harm our business, financial condition, and results of operations. Legal disputes are likely to be ~~held liable for significant damages.~~costly and time consuming to defend.

We seek to obtain licenses to patents when, in our judgment, such licenses are needed. If any licenses are required, we may not be able to obtain ~~any required license~~such licenses on commercially ~~acceptable~~reasonable terms, if at all. 10 ~~If we are not able~~The failure to ~~keep~~obtain any such license could prevent us from developing or commercializing any one or more of our ~~trade secrets confidential,~~product candidates, which could severely harm our ~~technology~~business.

There has been significant volatility in our stock price and information may be used by others to compete against us. In addition to our reliance on patents, we attempt to protect our proprietary products and processes by relying on trade secret laws, nondisclosure and confidentiality agreements, and exclusive licensing arrangements with our employees and certain other persons who have access to our proprietary products or processes or have licensing or research arrangements exclusive to us. These agreements or arrangements may not provide meaningful protection for our proprietary products and processesgenerally in the ~~event~~market prices of ~~unauthorized use or disclosure of such information. Others may independently develop substantially equivalent proprietary information~~biotechnology companies’ securities. Various factors and techniques or otherwise gain access to our trade secrets or technology which will adversely affect our competitive position. If we breach any of the agreements under which we license technology from others, we could lose license rights that are important to our business. We are a party to technology licenses that are important to our business and expect to enter into additional licenses in the future. These licenses impose commercialization, sublicensing, royalty, insurance and other obligations on us. If we fail to comply with these requirements, our licensorsevents may have ~~the right to terminate our licenses which would have~~ a ~~negative~~significant impact on ~~our business. RISKS RELATING TO OUR COMMON STOCK Our stock~~the market price ~~could be volatile. Since the notes are convertible into shares~~ of our common ~~stock,~~ stock. These factors include, by way of example:


	•	progress, delays or adverse results in clinical trials;

	•	announcement of technological innovations or product candidates by us or competitors;


	•	fluctuations in our operating results;

	•	public concern as to the safety or effectiveness of our product candidates;

	•	developments in our relationship with collaborative partners;

	•	developments in the biotechnology industry or in government regulation of healthcare;

	•	large sales of our common stock by our executive officers, directors or significant shareholders;

	•	arrivals and departures of key personnel; and

	•	general market conditions.

The trading price of our common stock ~~may affect the price of the notes. There~~ has been, and could continue to be, subject to wide fluctuations in response to these and other factors, including the sale or attempted sale of a ~~history~~large amount of ~~significant volatility~~our common stock in the market. Broad market fluctuations may also adversely affect the market price of our common stock.

A small number of our shareholders beneficially own a substantial amount of our common stock. As of December 6, 2004, our six largest shareholders, which include Aventis and Novartis, beneficially owned 47.5% of our outstanding common shares, assuming, in the case of Leonard S. Schleifer, M.D., Ph.D, our chief executive officer, the exercise of all options held by him which are exercisable within 60 days of December 6, 2004. As of that date, Novartis owned 7,527,050 shares of ~~biotechnology companies, including~~common stock, representing approximately 13.5% of the common shares then outstanding. Under our registration rights agreement with Novartis, these shares of common stock may generally not be sold or otherwise transferred by Novartis until after March 28, 2005. As described under the caption “Registration Rights of One of Our Shareholders” found on page 15 of this prospectus, commencing after March 28, 2005, Novartis has certain registration rights with respect to these shares. As of December 6, 2004, Aventis owned 2,799,522 shares of common stock, representing approximately 5.0% of the common shares then outstanding. Under our stock purchase agreement with Aventis, these shares may generally not be sold or otherwise transferred until after September 5, 2005, and ~~it is likely~~for one year after that date, Aventis may sell no more than 250,000 shares in any calendar quarter. After September 5, 2006, Aventis may sell no more than 500,000 shares in any calendar quarter. Accordingly, in 2005 and thereafter, as the restrictions on transfer applicable to the shares of common stock owned by Novartis and Aventis expire, these shares will be freely tradeable in the public market, subject, in the case of Aventis, to the foregoing continuing contractual sales volume restrictions. If Novartis or Aventis, or our other significant shareholders or we, sell substantial amounts of our common stock in the public market, or the perception that such sales may occur exists, the market price of our common stock ~~will continue~~could fall. Sales by our significant shareholders, including Aventis and Novartis, also might make it more difficult for us to ~~be highly volatile. The following factors may have~~raise funds by selling equity or equity-related securities in the future at a ~~significant effect on the market~~time and price of our common stock: - fluctuations in our operating results; - clinical trial results; - announcements of technological innovations or new commercial therapeutic products introduced by us or our competitors; - governmental regulation; - regulatory delays; - litigation; - developments in patent or other proprietary rights; - public concern as to the safety or other implications of the drugs sought to be developed by us or the genetic engineering involved in their production; and - general market conditions. Any clinical trial results that ~~are below the expectations of financial analysts or investors would most likely cause our stock price to drop dramatically.~~ we deem appropriate.

Holders of Class A stock, who are the shareholders who purchased their stock from us before our initial public offering, are entitled to ten votes per share, ~~and~~while holders of common stock are entitled to one vote per share. As of December ~~31, 2001,~~6, 2004, holders of Class A stock held ~~5.8%~~4.2% of ~~the total of our outstanding~~all shares of common stock and Class A stock ~~or collectively, our common shares,~~then outstanding, and had 11 ~~38.3%~~30.6% of the combined voting power of ~~the~~all common shares. These shareholders, if acting together, ~~will~~would be in a position to significantly influence the election of our directors and to effect or prevent certain corporate transactions that require majority or supermajority approval of the combined classes, including mergers and other business combinations. This may result in ~~the~~our company taking

corporate actions that you may not consider to be in your best interest and may affect the price of our common stock. As of December 31, 2001: - our current officers and directors held 8.8% of our outstanding common shares and 36.8% of the combined voting power of our common shares; and - our five largest shareholders held 48.6% of our outstanding common shares and 32.2% of the combined voting power of our common shares, in each case, assuming conversion of notes held by them. We have anti-takeover defenses that could delay or prevent an acquisition and could adversely affect the price of our common stock. New York corporate law6, 2004:


	•	our current officers and directors beneficially owned 14.8% of our outstanding common shares and 34.3% of the combined voting power of our common shares, assuming the exercise of all options held by such persons which are exercisable within 60 days of December 6, 2004; and

	•	our six largest shareholders beneficially owned 47.5% of our outstanding common shares and 54.5% of the combined voting power of our common shares, assuming, in the case of Leonard S. Schleifer, M.D., Ph.D, our chief executive officer, the exercise of all options held by him which are exercisable within 60 days of December 6, 2004.

Our amended and restated certificate of incorporation, our by-laws, our rights agreement and ~~by-laws~~the New York Business Corporation Law contain various provisions that could have the effect of delaying or preventing a change in control of our company or our management that shareholders may consider favorable or beneficial. ~~These~~Some of these provisions could discourage proxy contests and make it more difficult for you and other shareholders to elect directors and take other corporate actions. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock. These provisions include: - authorization to issue "blank check" preferred stock, which is preferred stock that can be created and issued by the board of directors without prior shareholder approval, with rights senior to our common stockholders; and - a staggered board of directors, so that it would take three successive annual meetings to replace all of our directors.


	•	authorization to issue “blank check” preferred stock, which is preferred stock that can be created and issued by the board of directors without prior shareholder approval, with rights senior to those of our common shareholders;

	•	a staggered board of directors, so that it would take three successive annual meetings to replace all of our directors;

	•	a requirement that removal of directors may only be effected for cause and only upon the affirmative vote of at least eighty percent (80%) of the outstanding shares entitled to vote for directors, as well as a requirement that any vacancy on the board of directors may be filled only by the remaining directors;

	•	any action required or permitted to be taken at any meeting of shareholders may be taken without a meeting, only if, prior to such action, all of our shareholders consent, the effect of which is to require that shareholder action may only be taken at a duly convened meeting;

	•	any shareholder seeking to bring business before an annual meeting of shareholders must provide timely notice of this intention in writing and meet various other requirements; and

	•	under the New York Business Corporation Law, a plan of merger or consolidation of the Company must be approved by 2/3 of the votes of all outstanding shares entitled to vote thereon. See the risk factor immediately above captioned“Our existing shareholders may be able to exert significant influence over matters requiring shareholder approval.”

In addition, we have a ~~shareholders~~shareholder rights plan which ~~will~~could make it more difficult for a third party to acquire us without the support of our board of directors and principal shareholders. ~~A significant number~~See “Description of Capital Stock-Rights Plan.” In addition, many of our shares are eligible for resale. This could reduce our share price and impair our ability to raise funds in new share offerings. As of December 31, 2001, our five largest shareholders held 48.6% of our outstanding common shares, assuming conversion of notes held by them. Any of these shareholders acting individually could cause a significant number of shares of our common stock to be sold in the public market which could cause our stock price to decline. As of December 31, 2001, we had 43,826,969 common shares outstanding. In addition, we had 9,328,039 outstanding stock options ~~held by~~issued under our ~~directors, officers and employees~~2000 Long-Term Incentive Plan may become fully vested in connection with a “change in control” of the Company, as of December 31, 2001. Sales of substantial amounts of shares of our common stock into the public market after this offering, or the perception that those sales may occur, could cause the market price of our common stock to decline. Those sales also might make it more difficult for us to sell equity and equity-related securities in the future at a time and at a price that we consider appropriate. RISKS RELATED TO THE NOTES The notes are subordinated to any existing and future Senior Indebtedness. The notes are contractually subordinated in right of payment to our existing and future Senior Indebtedness (as the term is defined in the ~~indenture). This means that~~plan.

Unless otherwise stated in the ~~payment~~applicable prospectus supplement, we intend to use the net proceeds of ~~the principal~~any securities sold by us to fund pre-clinical and ~~interest on the notes is subordinated to the prior payment in full of all~~clinical development of our ~~existing and future Senior Indebtedness. However, payment from the money or the proceeds from the U.S. government securities pledged~~product candidates, to ~~the trustee as security for the exclusive benefit of the holders of the notes, as described under "Description of the Notes -- Security" or amounts deposited with the trustee~~fund basic research activities, to ~~pay and discharge all 12~~ outstanding notes, as described under "Description of the Notes -- Satisfaction and Discharge," will not be subordinated to any Senior Indebtedness or subject to the subordination restrictions described in this offering memorandum. As of December 31, 2001, we had approximately $21.8 million of Senior Indebtedness. Our Senior Indebtedness ranks prior in right of payment to the notes. The indenture does not limit the creation of additional indebtedness. Any significant additional indebtedness incurred may adversely affect our ability to service our debt, including the notes. Due to the subordination provisions, in the eventcontinue development of our ~~insolvency, funds which we would otherwise use~~technology platforms, for capital expenditures, to ~~pay the holders of the~~redeem, repay or purchase our 5 1/2% convertible senior subordinated notes ~~will be used to pay the holders of Senior Indebtedness to the extent necessary to pay the Senior Indebtedness in full. As a result of these payments, our~~due October 17, 2008, and for general creditors may recover more, ratably, than the holders of the notes. In addition, the holders of Senior Indebtedness may restrict or prohibit us from making payments on the notes. We may not be able to repurchase the notes, if required. In some circumstances involving a Change of Control (as defined below), the holders of the notes may require us to repurchase some or all of the notes. We may not have sufficient financial resources at such time, or the ability to arrange financing to pay the repurchase price of the notes. Our ability to repurchase the notes in such event may be limited by law, the indenture, by the terms of other agreements relating to our Senior Indebtedness and as such indebtedness and agreements may be entered into, replaced, supplemented or amended from time to time. We may be required to refinance our Senior Indebtedness in order to make such payments. Our outstanding indebtedness will increase substantially with the issuance of the notes and we may not be able to pay our debtcorporate purposes, including working capital, acquisitions, and other obligations. As of December 31, 2001, we had approximately $200.6 million in long-term debt which includes $200 million incurred in connection with the sale of the notes. This increased indebtedness will: - make it more difficult for us to obtain any necessary financing in the future for working capital, capital expenditures, debt service requirements or other purposes; - significantly increase our interest expense and related debt service costs; and - make us more vulnerable in the event of a downturn in our business. Currently, we do not have any product sales and we are not generating sufficient cash flow to satisfy the annual debt service payments that will be required as a result of the consummation of the sale of the notes. This may require us to use a portion of the proceeds from the sale of the notes to pay interest or borrow additional funds or sell additional equity to meet our debt service obligations after the first three years when the notes are no longer secured. If we are unable to satisfy our debt service requirements, we will default on the notes. An active trading market for the notes may not develop. The notes are a new issue of securities for which there is currently no trading market. Although the notes that were sold to qualified institutional buyers pursuant to Rule 144 A are eligible for trading in the PORTAL market, the notes resold pursuant to this prospectus will no longer trade on the PORTAL market. As a result, there may be a limited market for the notes. Accordingly, we cannot predict whether an active trading market for the notes will develop or be sustained. If an active trading market for the notes fails to develop or be sustained, the notes could trade at prices that may be lower than the initial offering price of the notes. Whether or not the notes will trade at lower prices depends on many factors, including: - prevailing interest rates and the markets for similar securities; - the market price of our common stock; - general economic conditions; and - our financial condition, financial performance and future prospects. 13 business opportunities.

The ~~ratios~~following table sets forth our ratio of earnings to combined fixed charges and preferred stock dividends, if any, for the ~~fiscal years indicated are stated below.~~ periods presented. We had no preferred stock outstanding for any of these periods.


(A)	Due to our losses in the years ended December 31, 1999, 2000, 2001, 2002, and 2003, the ratio coverage was less than 1:1 for those periods. We would have needed to generate additional earnings of $18.9 million, $17.1 million, $75.2 million, $124.6 million, and $107.6 million, for the years ended December 31, 1999, 2000, 2001, 2002, and 2003, respectively, to have achieved a coverage of 1:1.

For purposes of computing ~~the~~these ratios, earnings ~~represent~~represents net income (loss) ~~from continuing operations~~ before income taxes plus fixed ~~charges and taxes, and~~charges. Combined fixed charges represent ~~gross~~ interest expense, capitalized interest, amortization of deferred financing costs, and asuch portion of rental expense, ~~which is~~ deemed ~~to be~~ representative of the interest factor.
~~FISCAL YEAR RATIO ------ -----~~ 2000 * 1999 * 1998 * 1997 * 1996 *
~~For~~The denominator is increased for preferred stock dividend requirements, if any, which represent the ~~nine months ended September 30, 2001, the ratio~~amount of pre-tax earnings required to fixed charges was *. * Due to the registrant's losses in the years ended December 31, 2000, 1999, 1998, 1997 and 1996 and the nine-months ended September 30, 2001, the ratio coverage was less than 1:1. The registrant must generate additional earnings of $17.1 million, $18.9 million, $6.1 million, $8.2 million, $18.2 million and $46.7 million for the years ended December 31, 2000, 1999, 1998, 1997 and 1996 and for the nine-months ended September 30, 2001, respectively, to achieve a coverage of 1:1. USE OF PROCEEDS We will not receive any of the proceeds from the sale by any selling securityholder of the notes or shares of common stock offered under this prospectus. DIVIDEND POLICY We have never paid cash dividends and do not anticipate paying any in the foreseeable future. 14 cover such dividend requirements.

DESCRIPTION OF THE NOTES The notes were issued under an indenture between us and American Stock Transfer & Trust Company, as trustee, to be dated October 17, 2001. The terms of the notes include those provided in the indenture and those provided in the pledge agreement and the registration rights agreement, which we entered into with the initial purchasers. As used in this description, the words "we," "us," "our" or "Regeneron" do not include any current or future subsidiary of Regeneron Pharmaceuticals, Inc. The following description of provisions of the notes is not complete and is subject to, and qualified in its entirety by reference to, the notes, the indenture, the pledge agreement and the registration rights agreement. GENERAL The notes represent general unsecured (except to the extent described under "-- Security") obligations of Regeneron and will rank junior in right of payment to all of our existing and future senior debt.SECURITIES

This means that the payment of the principal, premium, if any, and interest on the notes is subordinated to the prior payment in full of all of our existing and future Senior Indebtedness (as defined below). However, payment from the money or the proceeds from the U.S. government securities pledged to the trustee as security for the notes and for the exclusive benefit of the holders of the notes, as described under "-- Security" or amounts deposited with the trustee to pay and discharge all outstanding notes, as described under "-- Satisfaction and Discharge," will not be subordinated to any Senior Indebtedness or subject to the subordination restrictions described in this prospectus. The notes will rank equally with all our existing and future senior subordinated indebtedness. The notes will be convertible into shares of our common stock as described under "-- Conversion Rights." The notes are limited to $200 million aggregate principal amount, and will mature on October 17, 2008, unless earlier redeemed by us or repurchased by us at the option of the holder upon the occurrence ofprospectus contains a Change of Control (as defined below). The notes bear interest from October 17, 2001 at the rate of 5 1/2% per year. Interest is payable semi-annually on April 17 and October 17 of each year to holders of record at the close of business on the immediately preceding April 2 and October 2, respectively, beginning April 17, 2002. We may pay interest on notes represented by certificated notes by check mailed to such holders. However, a holder of notes with an aggregate principal amount in excess of $10 million may elect to be paid by wire transfer in immediately available funds. Interest will be computed on the basis of a 360-day year comprised of twelve 30-day months. Principal will be payable, and the notes may be presented for conversion, registration of transfer and exchange, without service charge, at our office or agency in New York City, which shall initially be the office or agency of the trustee in New York, New York. The indenture does not contain any financial covenants or any restrictions on the payment of dividends, the repurchase of our securities or the incurrence of Senior Indebtedness or any other indebtedness. The indenture also does not contain any covenants or other provisions that afford protection to holders of notes in the event of a highly leveraged transaction or a change of control of Regeneron except to the extent described under "-- Repurchase at Option of Holders Upon a Change of Control" below. SECURITY On October 17, 2001, we purchased and pledged to the trustee as security for the notes and for the exclusive benefit of the holders of the notes (and not for the benefit of our other creditors), $31.6 million of U.S. government securities. These securities, when held and invested by the trustee in accordance with the terms of the pledge agreement that we entered into with the trustee, will be sufficient upon receipt of scheduled interest and principal payments of such securities to provide for payment in full of the first six scheduled interest payments due on the notes when due. 15 The U.S. government securities were pledged by us to the trustee for the exclusive benefit of the holders of the notes and are being held by the trustee in a pledge account. Immediately prior to an interest payment date, the trustee will release from the pledge account proceeds sufficient to pay interest then due on the notes. We may also make additional payments to the trustee to ensure that sufficient funds are available to pay interest then due on the notes if necessary. A failure to pay interest on the notes when due through the first six scheduled interest payment dates will constitute an Event of Default (as defined below) under the indenture. The pledged U.S. government securities and the pledge account will also secure the repayment of the principal amount on the notes. If prior to October 17, 2004: - an Event of Default under the notes or the indenture occurs and is continuing; and - the trustee or the holders of 25% in aggregate principal amount of the notes accelerate the notes by declaring the principal amount of the notes to be immediately due and payable (by written consent, at a meeting of note holders or otherwise), except for the occurrence of an Event of Default relating to our bankruptcy, insolvency or reorganization, upon which the notes will be accelerated automatically, then the proceeds from the pledged U.S. government securities will be promptly released for payment to note holders, subject to the automatic stay provisions of bankruptcy law, if applicable. Distributions from the pledge account will be applied: - first, to any accrued and unpaid interest on the notes; and - second, to the extent available, to the repayment of a portion of the principal amount of the notes. If any Event of Default is not cured prior to the acceleration of the notes by the trustee or holders of the notes referred to above, the trustee and the holders of the notes will be able to accelerate the notes as a result of that Event of Default. For example, if the first two interest payments were made when due but the third interest payment was not made when due and the note holders promptly exercised their right to declare the principal amount of the notes to be immediately due and payable, then, assuming automatic stay provisions of bankruptcy law are inapplicable and the proceeds of the pledged U.S. government securities are promptly distributed from the pledge account, - an amount equal to the interest payment due on the third interest payment would be distributed from the pledge account as accrued interest; and - the balance of the proceeds of the pledge account would be distributed as a portion of the principal amount of the notes. In addition, note holders would have an unsecured claim against us for the remainder of the principal amount of their notes. Once we make the first six scheduled interest payments on the notes, all of the remaining pledged U.S. government securities and cash, if any, will be released to us from the pledge account and thereafter the notes will be unsecured. CONVERSION RIGHTS The holders of notes may, at any time prior to the close of business on the final maturity date of the notes, convert any outstanding notes (or portions thereof) into shares of our common stock, initially at the conversion price of $30.2512 per share is subject to adjustment as described below. Holders may convert notes only in denominations of $1,000 and whole multiples of $1,000. Except as described below, no adjustment will be made to the conversion price of any notes for interest accrued thereon or dividends paid on any common stock. 16 If notes are converted after a record date for an interest payment but prior to the next interest payment date, those notes, other than notes called for provisional or optional redemption, must be accompanied by funds equal to the interest payable on the next interest payment date on the principal amount so converted. No such payment will be required from a holder if we exercise our right to redeem such notes. We are not required to issue fractional shares of our common stock upon conversion of the notes. Instead, we will pay a cash adjustment based upon the market price of our common stock on the last business day before the date of the conversion. In the case of notes called for redemption, conversion rights will expire at the close of business on the business day preceding the date fixed for redemption, and in the case of notes tendered for repurchase in connection with a Change of Control, conversion rights will expire at the close of business on the date specified in the Change of Control notice, unless we default in payment of the redemption or Change of Control repurchase price. The conversion price will be adjusted for certain events, including: (1) the issuance of our common stock as a dividend or distribution on our common stock; (2) certain subdivisions and combinations of our common stock; (3) the issuance to all holders of our common stock of certain rights or warrants to purchase our common stock (or securities convertible into our common stock) at less than (or having a conversion price per share less than) the then current market price of our common stock; (4) the dividend or other distribution to all holders of our common stock of shares of our capital stock (other than common stock) or our debt instruments or our assets (including securities, but excluding: (A) those rights and warrants referred to in item (3) above, (B) dividends or distributions in connection with a reclassification, consolidation, merger, combination, sale or conveyance resulting in a change in the conversion consideration pursuant to the second succeeding paragraph and (C) dividends or distributions paid exclusively in cash); (5) dividends or other distributions consisting exclusively of cash to all holders of our common stock to the extent that such distributions, combined together with (A) all other such all-cash distributions made within the preceding 12 months for which no adjustment has been made plus (B) any cash and the fair market value of other consideration paid for any tender offers by us or any of our subsidiaries for our common stock concluded within the preceding 12 months for which no adjustment has been made, exceeds 5% of our market capitalization on the record date for such distribution; market capitalization is the product of the then current market pricesummary of our common stock and ~~the number of shares of our~~Class A stock, preferred stock, debt securities, and warrants to purchase common stock, ~~then outstanding;~~preferred stock, and (6) the purchase of our common stock pursuant to a tender offer made by us or any of our subsidiaries which involves an aggregate consideration that, together with (A) any cash and the fair market value of any other consideration paid in any other tender offer by us or any of our subsidiaries for our common stock expiring within the 12 months preceding such tender offer for which no adjustment has been made plus (B) the aggregate amount of any all-cash distributions referred to in clause (5) above to all holders of our common stock within 12 months preceding the expiration of that tender offer for which no adjustments have been made, exceeds 5% of our market capitalization on the expiration of such tender offer. In the event that we pay a dividend or make a distribution on shares of our common stock consisting of capital stock of, or similar equity interests in, a subsidiary or other business unit of ours, the conversion rate will be adjusted based on the market value of the securities so distributed relative to the market value of our common stock, in each case, based on the average closing prices of those securities for the 10 trading days commencing on and including the fifth trading day after the date on which the "ex-dividend trading" commences for such dividend or distribution on the principal United States securities exchange or market on which the securitiesdebt securities. These summaries are then listed or quoted. No adjustment in the conversion price will be required unless such adjustment would require a change of at least 1% in the conversion price then in effect at such time. However, any adjustment that would 17 ~~otherwise be required to be made but for the fact that such 1% threshold has~~ not been met shall be carried forward and taken into account for the purposes of any subsequent adjustments. Except as stated above, the conversion price will not be adjusted for the issuance of our common stock or any securities convertible into or exchangeable for our common stock or carrying the right to purchase any of the foregoing. In the case of: - any reclassification of or change in our common stock (other than changes resulting from a subdivision or combination); or - a consolidation, merger or combination involving us or a sale or conveyance to another corporation of all or substantially all of our property and assets, in each case, as a result of which holders of our common stock are entitled to receive stock, other securities, other property or assets (including cash or any combination thereof) with respect to or in exchange for our common stock, the holders of the notes then outstanding will be entitled thereafter to convert those notes into the kind and amount of shares of stock, other securities or other property or assets (including cash or any combination thereof) which they would have owned or been entitled to receive upon such reclassification, change, consolidation, merger, combination, sale or conveyance had such notes been converted into our common stock immediately prior to such reclassification, change, consolidation, merger, combination, sale or conveyance. We may not become a party to any such transaction unless its terms are consistent with the foregoing. If a taxable distribution to holders of our common stock or other transaction occurs which results in any adjustment of the conversion price, the holders of notes may, in certain circumstances, be deemed to have received a distribution subject to United States federal income tax as a dividend. In certain other circumstances, the absence of an adjustment may result in a taxable dividend to the holders of common stock. See "Certain United States Federal Income Tax Considerations." We may from time to time, to the extent permitted by law, reduce the conversion price of the notes by any amount for any period of at least 20 days. In that case, we will give at least 15 days' notice of such decrease. We may make such reductions in the conversion price, in addition to those set forth above, as our board of directors deems advisable to avoid or diminish any income tax to holders of our common stock resulting from any dividend or distribution of stock (or rights to acquire stock) or from any event treated as such for income tax purposes. PROVISIONAL REDEMPTION BY REGENERON We may redeem the notes, in whole or in part, at any time prior to October 17, 2004, at a redemption price equal to $1,000 per $1,000 principal amount of notes to be redeemed plus accrued and unpaid interest, if any, to, but excluding, the provisional redemption date if: - the closing price of our common stock has exceeded 150% of the conversion price then in effect for at least 20 trading days within a period of 30 consecutive trading days ending on the trading day prior to the date on which we mail the provisional redemption notice (which date shall be at least 30 days but not more than 60 days prior to the provisional redemption date); and - during the period that we are obligated under the registration rights agreement to keep the shelf registration statement effective, such shelf registration statement covering resales of the notes and the common stock issuable upon conversion of the notes is effective and available for use as of, and including, the date on which we mail the provisional redemption notice through and including the provisional redemption date. If we do not redeem all of the notes, the trustee will select the notes to be redeemed in principal amounts of $1,000 or whole multiples of $1,000 by lot or on a pro rata basis. If any notes are to be redeemed in part only, a new note or notes in principal amount equal to the unredeemed principal portion 18 thereof will be issued. If a portion of a holder's notes is selected for partial redemption and the holder thereafter converts a portion of its notes, the converted portion will be deemed to be taken from the portion selected for redemption. Upon any provisional redemption, we will make an additional "make-whole" payment in cash with respect to the notes called for redemption to holders on the notice date in an amount equal to $165 per $1,000 principal amount of notes, less the amount of any interest actually paid on the notes on or prior to the provisional redemption date. We will be obligated to make this additional payment on all notes called for provisional redemption, including any notes converted after the notice date and before the provisional redemption date. OPTIONAL REDEMPTION BY REGENERON At any time on or after October 17, 2004, we may redeem some or all of the notes on at least 30 days' but not more than 60 days' notice, at a price equal to $1,000 per $1,000 principal amount, plus accrued and unpaid interest to, but excluding, the date fixed for redemption, subject to the right of holders of record on the relevant record dates to receive interest payments due on an interest payment date, if the closing price of our common stock has exceeded 140% of the conversion price then in effect for at least 20 trading days within a period of 30 consecutive trading days ending on the trading day prior to the date on which we mail the optional redemption notice. If we do not redeem all of the notes, the trustee will select the notes to be redeemed in principal amounts of $1,000 or whole multiples of $1,000 by lot or on a pro rata basis. If any notes are to be redeemed in part only, a new note or notes in principal amount equal to the unredeemed principal portion thereof will be issued. If a portion of a holder's notes is selected for partial redemption and the holder thereafter converts a portion of its notes, the converted portion will be deemed to be taken from the portion selected for redemption. SINKING FUND No sinking fund is provided for the notes. REPURCHASE AT OPTION OF HOLDERS UPON A CHANGE OF CONTROL If a Change of Control (as defined below) occurs, each holder of notes will have the right to require us to repurchase all of that holder's notes not previously called for redemption, or any portion of those notes that is equal to $1,000 or a whole multiple of $1,000, on the date that is no later than 30 days after the date we give notice of the occurrence of a Change in Control (such date being the repurchase date) at a repurchase price equal to 100% of the principal amount of the notes to be repurchased, together with interest accrued and unpaid to, but excluding, the repurchase date. We may elect to pay the repurchase price in common stock instead of cash if we so specify in our Change of Control notice referred to below. The number of shares of common stock a holder will receive will equal the repurchase price divided by 95% of the average of the closing prices of our common stock for the five-trading-day period ending on the third business day prior to the repurchase date. However, we may not pay in common stock unless we satisfy certain conditions prior to the repurchase date, as provided in the indenture. Within 30 days after the occurrence of a Change of Control, we are required to give notice to all holders of notes, as provided in the indenture, of the occurrence of the Change of Control and of their resulting repurchase right and specifying our form of payment. We must also deliver a copy of our notice to the trustee. In order to exercise the repurchase right, a holder of notes must deliver, on or prior to the 30th day after the date of our notice, written notice to the trustee of the holder's exercise of the holder's repurchase right, together with the notes with respect to which the repurchase right is being exercised. 19 Under the indenture, a "Change of Control" of Regeneron will be deemed to have occurred at such time after the original issuance of the notes when the following has occurred: - the acquisition by any person (other than permitted holders) of beneficial ownership, directly or indirectly, through a purchase, merger or other acquisition transaction or series of transactions of shares of our capital stock entitling that person to exercise 50% or more of the total voting power of all shares of our capital stock entitled to vote generally in elections of directors, other than any acquisition by us, any of our subsidiaries or any of our employee benefit plans; - any permitted holder files a schedule, form or report in connection with a transaction or event disclosing that such person has become the beneficial owner of 50% or more of the total voting power of all shares of our capital stock entitled to vote generally in elections of directors, as a result of which (i) our common stock ceases (or, upon consummation of or immediately following such transaction or event, will cease) to be listed on a United States national securities exchange or approved for quotation on the Nasdaq National Market or any similar United States system for automated dissemination of quotations of securities prices or (ii) less than 5 million shares of our common stock remain held by persons other than permitted holders; or - our consolidation or merger with or into any other person, any merger of another person into us, or any conveyance, transfer, sale, lease or other disposition of all or substantially all of our properties and assets to another person, other than: (1) any transaction pursuant to which holders of our capital stock immediately prior to the transaction have the entitlement to exercise, directly or indirectly, 50% or more of the total voting power of all shares of our capital stock entitled to vote generally in the election of directors of the continuing or surviving person immediately after the transaction; and (2) any merger solely for the purpose of changing our jurisdiction of incorporation and resulting in a reclassification, conversion or exchange of outstanding shares of common stock solely into shares of common stock of the surviving entity. For the purposes of the foregoing, "permitted holders" shall mean (A) Leonard S. Schleifer, M.D., Ph.D., our Chief Executive Officer and President, and P. Roy Vagelos, M.D., our Chairman of the Board, and their respective spouses, immediate family members, estates, lineal descendants, executors or administrators, or (B) any trust, corporation or other entity, the beneficiaries, stockholders or other persons beneficially holding an 80% or more controlling interest of which consist of persons or entities referred to in clause (A). The beneficial owner shall be determined in accordance with Rule 13d-3 promulgated by the SEC under the Exchange Act. The term "person" includes any syndicate or group which would be deemedmeant to be a ~~"person" under Section 13(d)(3)~~complete description of the Exchange Act. Rule 13e-4 under the Exchange Act, as amended, requires the dissemination of information to security holders if an issuer tender offer occurs and may apply if the repurchase option becomes available to holders of the notes. We will comply with this rule to the extent applicable at that time.each security. The foregoing provisions would not necessarily protect holders of the notes if highly leveraged or other transactions involving us occur that may adversely affect holders. Our ability to repurchase notes upon the occurrence of a Change of Control is subject to important limitations. The occurrence of a Change of Control could cause an Event of Default under, or be prohibited or limited by, theparticular terms of ~~our existing or future senior debt. As a result,~~ any ~~repurchase of the notes would, absent a waiver,~~security to be prohibited under the subordination provisions of the indenture until all of our senior debt is paid in full. Further, we cannot assure you that we would have the financial resources, or would be able to arrange financing, to pay the repurchase price for all the notes that might be delivered by holders of notes seeking to exercise the repurchase right. Any failure by us to repurchase the notes when required following a Change of Control would result in an event of default under the indenture, whether or 20 not such repurchase is permitted by the subordination provisions of the indenture. Any such default may, in turn, cause a default under our existing or future senior debt. See "-- Subordination" below. SUBORDINATION The payment of principal of, premium, if any, and interest on the notes (other than payments made toward the first six scheduled interest payments due on the notes, which payments are derived from the U.S. government securities pledged by us to the trustee for the exclusive benefit of the holders of the notes (hereinafter referred to as "Permitted Interest Payments"))issued pursuant hereto will be ~~subordinated in right of payment, as~~ set forth in a related prospectus supplement. This prospectus and the ~~indenture, to~~accompanying prospectus supplement will contain the prior payment in full in cash or cash equivalents of all Senior Indebtedness (as defined below), whether outstanding on the date of the indenture or thereafter incurred. In the event of any insolvency or bankruptcy case or proceeding, or any receivership, liquidation, reorganization or other similar case or proceeding in connection therewith, relating to Regeneron or to its assets, or any liquidation, dissolution or other winding-up of Regeneron, whether voluntary or involuntary, or any assignment for the benefit of creditors or other marshaling of assets or liabilities of Regeneron (except in connection with the consolidation or merger of Regeneron or its liquidation or dissolution following the conveyance, transfer or lease of all or substantially all of its properties and assets upon thematerial terms and conditions described under "-- Mergers and Sales of Assets" below), the holders of Senior Indebtedness will be entitled to receive payment in full in cash or cash equivalents of all Senior Indebtedness, or provision shall be made for such payment in full, before the holders of notes will be entitled to receive any payment or distribution of any kind or character (other than Permitted Interest Payments and other than any payment or distribution in the form of equity securities or subordinated securities of Regeneron or any successor obligor that, in the case of any such subordinated securities, are subordinated in right of payment to all Senior Indebtedness that may at the time be outstanding to at least the same extent as the notes are so subordinated (such equity securities or subordinated securities hereinafter being "Permitted Junior Securities")) on account of principal of, or premium, if any, or interest on the notes; and any payment or distribution of assets of Regeneron of any kind or character, whether in cash, property or securities (other than a payment or distribution in the form of Permitted Junior Securities), by set-off or otherwise, to which the holders of the notes or the trustee would be entitled but for the provisions of the indenture relating to subordination shall be paid by the liquidating trustee or agent or other person making such payment or distribution directly to the holders of Senior Indebtedness or their representatives ratably according to the aggregate amounts remaining unpaid on account of the Senior Indebtedness to the extent necessary to make payment in full of all Senior Indebtedness remaining unpaid, after giving effect to any current payment or distribution to the holders of such Senior Indebtedness. No payment or distribution of any assets of Regeneron of any kind or character, whether in cash, property or securities (other than Permitted Interest Payments and Permitted Junior Securities), may be made by or on behalf of Regeneron on account of principal of, premium, if any, or interest on the notes or on account of the purchase, redemption or other acquisition of notes upon the occurrence of any default in payment (whether at scheduled maturity, upon scheduled installment, by acceleration or otherwise) of principal of, premium, if any, or interest on Designated Senior Indebtedness (as defined below) beyond any applicable grace period (a "Payment Default") until such Payment Default shall have been cured or waived in writing or shall have ceased to exist or such Designated Senior Indebtedness shall have been discharged or paid in full in cash or cash equivalents. No payment or distribution of any assets of Regeneron of any kind or character, whether in cash, property or securities (other than Permitted Interest Payments and Permitted Junior Securities), may be made by or on behalf of Regeneron on account of principal of, premium, if any, or interest on the notes or on account of the purchase, redemption or other acquisition of notes during the period specified below (a "Payment Blockage Period") upon the occurrence of any default or event of default with respect to any Designated Senior Indebtedness other than any Payment Default, pursuant to which the maturity thereof may be accelerated (a "Non-Payment Default"), and receipt by the trustee of written notice thereof from 21 Regeneron or the representative of holders of the Designated Senior Indebtedness or the trustee for any such holder. The Payment Blockage Period will commence upon the date of receipt by the trustee of written notice from Regeneron or the representative of the holders of the Designated Senior Indebtedness in respect of which the Non-Payment Default exists, or the trustee for any such holder, and shall end on the earliest of: (1) 179 days thereafter (provided that any Designated Senior Indebtedness as to which such written notice was given shall not theretofore have been accelerated); (2) the date on which such Non-Payment Default is cured, waived or ceases to exist; (3) the date on which such Designated Senior Indebtedness is discharged or paid in full; or (4) the date on which such Payment Blockage Period shall have been terminated by written notice to the trustee or Regeneron from the trustee or such other representative initiating such Payment Blockage Period, after which Regeneron will resume making any and all required payments in respect of the notes, including any missed payments. In any event, not more than one Payment Blockage Period may be commenced during any period of 365 consecutive days. No Non-Payment Default that existed or was continuing on the date of the commencement of any Payment Blockage Period will be, or can be made, the basis for the commencement of a subsequent Payment Blockage Period, unless such Non-Payment Default has been cured or waived for a period of not less than 90 consecutive days subsequent to the commencement of such initial Payment Blockage Period. In the event that, notwithstanding the provisions of the preceding four paragraphs, if any payment or distribution shall be received by the trustee or any holder of the notes that is prohibited by such provisions, then and in such event such payment shall be paid over and delivered by such trustee or holder to the trustee or any other representative of holders of Senior Indebtedness, as their interest may appear, for application toward our Senior Indebtedness. Until all of our Senior Indebtedness is paid in full, holders of the notes shall be subrogated (equally and ratably with all other indebtedness that is equal in right of payment to the notes) to the rights of holders of Senior Indebtedness to receive distributions. Failure by Regeneron to make any required payment in respect of the notes when due or within any applicable grace period, whether or not occurring during a Payment Blockage Period, will result in an Event of Default (as defined below) and, thereafter, holders of the notes will have the right to accelerate the maturity thereof. See "-- Events of Default." By reason of such subordination, in the event of liquidation, receivership, reorganization or insolvency of Regeneron, our general creditors may recover less, ratably, than holders of senior debt and such general creditors may recover more, ratably, than holders of notes. At December 31, 2001, on a pro forma basis, giving effect to the offering of notes: - the total outstanding Senior Indebtedness of Regeneron would have been approximately $221.8 million; and - Regeneron would have had no subordinated indebtedness other than the notes. "Designated Senior Indebtedness" means any Senior Indebtedness which, at the time of determination, has an aggregate principal amount outstanding of at least $25.0 million and that has been specifically designated in the instrument evidencing such Senior Indebtedness as "Designated Senior Indebtedness" of Regeneron. "indebtedness" means, with respect to any person, without duplication: - all liabilities of such person for borrowed money (including overdrafts) or for the deferred purchase price of property or services, excluding any trade payables and other accrued current liabilities incurred in the ordinary course of business, but including, without limitation, all obligations, 22 contingent or otherwise, of such person in connection with any letters of credit and acceptances issued under letter of credit facilities, acceptance facilities or other similar facilities; - all obligations of such person evidenced by bonds, notes, debentures or other similar instruments; - indebtedness of such person created or arising under any conditional sale or other title retention agreement with respect to property acquired by such person (even if the rights and remedies of the seller or lender under such agreement in the event of default are limited to repossession or sale of such property), but excluding trade payables arising in the ordinary course of business; - all capitalized lease obligations of such person; - all obligations of such person under or in respect of interest rate agreements or currency agreements; - all indebtedness referred to in (but not excluded from) the preceding clauses of other persons and all dividends of other persons, the payment of which is secured by (or for which the holder of such indebtedness has an existing right, contingent or otherwise, to be secured by) any lien or with respect to property (including, without limitation, accounts and contract rights) owned by such person, even though such person has not assumed or become liable for the payment of such indebtedness (the amount of such obligation being deemed to be the lesser of the value of such property or asset or the amount of the obligation so secured); - all guarantees by such person of indebtedness referred to in this definition or of any other person; - all Redeemable Capital Stock of such person valued at the greater of its voluntary or involuntary maximum fixed repurchase price plus accrued and unpaid dividends; and - the present value of the obligation of such person as lessee for net rental payments (excluding all amounts required to be paid on account of maintenance and repairs, insurance, taxes, assessments, water, utilities and similar charges to the extent included in such rental payments) during the remaining term of the lease included in such sale and leaseback transaction including any period for which such lease has been extended or may, at the option of the lessor, be extended. Such present value shall be calculated using a discount rate equal to the rate of interest implicit in such transaction, determined in accordance with accounting principles generally accepted in the United States. "Redeemable Capital Stock" means any class of our capital stock that, either by its terms, by the terms of any securities into which it is convertible or exchangeable or by contract or otherwise, is, or upon the happening of an event or passage of time would be, required to be redeemed (whether by sinking fund or otherwise) prior to the date that is 91 days after the final scheduled maturity of the notes or is redeemable at the option of the holder thereof at any time prior to such date, or is convertible into or exchangeable for debt securities at any time prior to such date (unless it is convertible or exchangeable solely at our option). "Senior Indebtedness" or "senior debt" means: - all obligations of Regeneron, now or hereafter existing, under or in respect of the documents and instruments executed in connection therewith, whether for principal, premium, if any, interest (including interest accruing after the filing of, or which would have accrued but for the filing of, a petition by or against Regeneron under bankruptcy law, whether or not such interest is allowed as a claim after such filing in any proceeding under such law) and other amounts due in connection therewith (including, without limitation, any fees, premiums, expenses, reimbursement obligations with respect to letters of credit and indemnities), whether outstanding on the date of the indenture or thereafter created, incurred or assumed; and - the principal of, premium, if any, and interest on all other indebtedness of Regeneron (other than the notes), whether outstanding on the date of the indenture or thereafter created, incurred or assumed, unless, in the case of any particular indebtedness, the instrument creating or evidencing 23 the same or pursuant to which the same is outstanding expressly provides that such indebtedness shall not be senior in right of payment to the notes. Notwithstanding the foregoing, "Senior Indebtedness" and "senior debt" shall not include: - indebtedness evidenced by the notes offered hereby; - indebtedness of Regeneron that is expressly subordinated in right of payment to Senior Indebtedness of Regeneron; - indebtedness of Regeneron that by operation of law is subordinate to any general unsecured obligations of Regeneron; - any liability for federal, state or local taxes or other taxes, owed or owing by Regeneron; - accounts payable or other liabilities owed or owing by Regeneron to trade creditors (including guarantees thereof or instruments evidencing such liabilities); - amounts owed by Regeneron for compensation to employees or for services rendered to Regeneron; - indebtedness of Regeneron to any subsidiary or any other affiliate of Regeneron or any of such affiliate's subsidiaries; - capital stock of Regeneron; - indebtedness evidenced by any guarantee of any indebtedness ranking equal or junior in right of payment to the notes; and - indebtedness which, when incurred and without respect to any election under Section 1111(b) of Title 11 of the United States Code, is without recourse to Regeneron. EVENTS OF DEFAULT Each of the following constitutes an "Event of Default" under the indenture: (1) our failure to pay when due the principal of or premium, if any, on any of the notes at maturity, upon redemption or exercise of a repurchase right or otherwise, whether or not such payment is prohibited by the subordination provisions of the indenture; (2) our failure to pay an installment of interest (including liquidated damages, if any) on any of the notes that continues for 30 days after the date when due, whether or not such payment is prohibited by the subordination provisions of the indenture; provided that a failure to make any of the first six scheduled interest payments on the notes within three business days of the applicable interest payment dates will constitute an Event of Default with no additional grace or cure period; (3) our failure to deliver shares of common stock, together with cash in lieu of fractional shares, when such common stock or cash in lieu of fractional shares is required to be delivered upon conversion of a note or upon the exercise of a repurchase right that continues for ten days after such delivery date; (4) our failure to perform or observe any other term, covenant or agreement contained in the notes or the indenture for a period of 60 days after written notice of such failure, requiring us to remedy the same, shall have been given to us by the trustee, or to us and the trustee by the holders of at least 25% in aggregate principal amount of the notes then outstanding; (5) (A) one or more defaults in the payment of principal of or premium, if any, on any of our indebtedness aggregating $10.0 million or more, when the same becomes due and payable at the scheduled maturity thereof, and such default or defaults shall have continued after any applicable grace period and shall not have been cured or waived within a thirty day period after the date of such default or (B) any of our indebtedness aggregating $10.0 million or more shall have been accelerated or otherwise declared due and payable, or required to be prepaid or repurchased (other than by 24 regularly scheduled required prepayment) prior to the scheduled maturity thereof and such acceleration is not rescinded or annulled within a thirty-day period after the date of such acceleration; (6) certain events of our bankruptcy, insolvency or reorganization or that of any significant subsidiaries; (7) our filing of a voluntary petition seeking liquidation, reorganization arrangement, readjustment of debts or for any other relief under the federal bankruptcy code; and (8) the agreement made by us in favor of the trustee governing the disbursements of funds from the pledge account, as such agreement may be amended, restated, supplemented or otherwise modified from time to time, shall cease to be in full force and effect or enforceable in accordance with its terms, other than in accordance with its terms. The indenture provides that the trustee shall, within 90 days of the occurrence of a default, give to the registered holders of the notes notice of all uncured defaults known to it, but the trustee shall be protected in withholding such notice if it, in good faith, determines that the withholding of such notice is in the best interest of such registered holders, except in the case of a default in the payment of the principal of, or premium, if any, or interest on any of the notes when due or in the payment of any redemption or repurchase obligation. If an Event of Default specified in clause (6) or clause (7) above occurs and is continuing, then, automatically, the principal of all the notes and the interest thereon shall become immediately due and payable. If an Event of Default shall occur and be continuing, other than with respect to clause (6) or clause (7) above (such default not having been cured or waived as provided under "-- Modifications and Waiver" below), the trustee or the holders of at least 25% in aggregate principal amount of the notes then outstanding may declare the notes due and payable at their principal amount together with accrued interest, and thereupon the trustee may, at its discretion, proceed to protect and enforce the rights of the holders of notes by appropriate judicial proceedings. Such declaration may be rescinded or annulled with the written consent of the holders of a majority in aggregate principal amount of the notes then outstanding upon the conditions provided in the indenture. The indenture contains a provision entitling the trustee, subject to the duty of the trustee during default to act with the required standard of care, to be indemnified by the holders of notes before proceeding to exercise any right or power under the indenture at the request of such holders. The indenture provides that the holders of a majority in aggregate principal amount of the notes then outstanding through their written consent may direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred upon the trustee. We will be required to furnish annually to the trustee a statement as to the fulfillment of our obligations under the indenture. CERTAIN COVENANTS The indenture provides that we will not, and will not permit our subsidiaries or other business units to, incur, create, assume, guarantee or in any other manner become directly or indirectly liable with respect to or responsible for, or permit to remain outstanding (other than if required by law), any indebtedness that is subordinate or junior in right of payment to Senior Indebtedness unless such indebtedness ranks equal or junior in right of payment to the notes. We have the right to incur, create, assume or guarantee or in any other manner become directly or indirectly liable with respect to, or responsible for, or permit to remain outstanding, different layers of Senior Indebtedness that may be subordinate to other Senior Indebtedness. 25 MERGERS AND SALES OF ASSETS We may, without the consent of the holders of notes, consolidate with, merge into or transfer all or substantially all of our assets to any other corporation organized under the laws of the United States or any of its political subdivisions provided that: - the surviving corporation assumes all our obligations under the indenture and the notes; - at the time of such transaction, no Event of Default, and no event which, after notice or lapse of time, would become an Event of Default, shall have happened and be continuing; and - certain other conditions are met. MODIFICATIONS AND WAIVER The indenture (including the terms and conditions of the notes) may be modified or amended by us and the trustee, without the consent of the holder of any note, for the purposes of, among other things: - adding to our covenants for the benefit of the holders of notes; - surrendering any right or power conferred upon us; - providing for conversion rights of holders of notes if any reclassification or change of our common stock or any consolidation, merger or sale of all or substantially all of our assets occurs; - providing for the assumption of our obligations to the holders of notes in the case of a merger, consolidation, conveyance, transfer or lease; - reducing the conversion price, provided that the reduction will not adversely affect the interests of holders of notes in any material respect; - complying with the requirements of the SEC in order to effect or maintain the qualification of the indenture under the Trust Indenture Act of 1939, as amended; - making any changes or modifications to the indenture necessary in connection with the registration of the notes under the Securities Act, as contemplated by the registration rights agreement, provided that this action does not adversely affect the interests of the holders of the notes in any material respect; - curing any ambiguity or correcting or supplementing any defective provision contained in the indenture; provided that such modification or amendment does not, in the good faith opinion of our board of directors and the trustee, adversely affect the interests of the holders of the notes in any material respect; - adding or modifying any other provisions which we and the trustee may deem necessary or desirable and which will not adversely affect the interests of the holders of notes in any material respect; or - to evidence and provide for the appointment of a successor trustee. Modifications and amendments to the indenture or to the terms and conditions of the notes may also be made, and past default by us may be waived, with the written consent of the holders of at least a majority in aggregate principal amount of the notes at the time outstanding. However, no such modification, amendment or waiver may, without the written consent of the holder of each note affected: - change the maturity of the principal of or any installment of interest on any note (including any payment of liquidated damages); - reduce the principal amount of, or any premium or interest on (including any payment of liquidated damages), any note; - change the currency of payment of such note or interest thereon; 26 - impair the right to institute suit for the enforcement of any payment on or with respect to any note; - modify our obligations to maintain an office or agency in New York City; - except as otherwise permitted or contemplated by provisions concerning corporate reorganizations, adversely affect the repurchase option of holders upon a change of control or the conversion rights of holders of the notes; - modify the subordination provisions of the notes in a manner adverse to the holders of notes; or - reduce the percentage in aggregate principal amount of notes outstanding necessary to modify or amend the indenture or to waive any past default. SATISFACTION AND DISCHARGE We may discharge our obligations under the indenture while notes remain outstanding, subject to certain conditions, if: - all outstanding notes have become due and payable or will become due and payable at their scheduled maturity within one year, or - all outstanding notes are scheduled for redemption within one year; and - in either case, we have deposited with the trustee an amount sufficient to pay and discharge all outstanding notes on the date of their scheduled maturity or the scheduled date of redemption; provided that we shall remain obligated to issue shares upon conversion of the notes. GOVERNING LAW The indenture and the notes are governed by, and will be construed in accordance with, the law of the State of New York. INFORMATION CONCERNING THE TRUSTEE American Stock Transfer & Trust Company, as trustee under the indenture, has been appointed by us as paying agent, conversion agent, registrar and custodian with regard to the notes. American Stock Transfer & Trust Company is also the transfer agent and registrar for our common stock. The trustee or its affiliates may from time to time in the future provide other services to us in the ordinary course of their business. REGISTRATION RIGHTS We entered into a registration rights agreement with the initial purchasers of the notes. If you sell the notes or shares of common stock issued upon conversion of the notes under this registration statement, you generally will be required to be named as a selling securityholder in this prospectus, deliver this prospectus to purchasers and be bound by applicable provisions of the registration rights agreement, including some indemnification provisions. In the registration rights agreement, we agreed to use our reasonable best efforts to keep the registration statement effective until the earlier of (1) October 17, 2003; (2) the date when the holders of the notes and the common stock issuable upon conversion of the notes are able to sell all such securities immediately without restriction pursuant to the volume limitation provisions of Rule 144 under the Securities Act or any successor rule thereto or otherwise; or (3) the sale pursuant to this shelf registration statement of all securities registered hereunder. We may suspend the use of this prospectus under certain circumstances relating to pending corporate developments, public filings with the SEC and similar events for a period not to exceed 45 days in any three-month period and not to exceed an aggregate of 120 days in any 12-month period. We also agreed to pay liquidated damages to holders of the notes and shares of common stock issued upon conversion of the 27 notes if this registration statement is not timely filed or made effective or if the prospectus is unavailable for periods in excess of those permitted above. You should refer to the registrations rights agreement for a description of these liquidated damages. BOOK-ENTRY SYSTEM The notes were originally issued in the form of a global security issued in reliance on Rule 144A. Upon the issuance of a global security, DTC (referred to as the depository) or its nominee credited the accounts of persons holding through it with the respective principal amounts of the notes represented by such global security. Such accounts were designated by the initial purchasers with respect to notes placed by the initial purchasers for us. The notes that are sold under this prospectus will be represented by a new unrestricted global security. Upon issuance of this new global security, the depository or its nominee will credit the accounts of persons holding through it with the respective principal amounts of the notes represented by the new unrestricted global security. Ownership of beneficial interests in a global security is limited to persons that have accounts with the depository ("participants") or persons that may hold interests through participants. Ownership of beneficial interests by participants in a global security is shown on, and the transfer of that ownership interest will be effected only through, records maintained by the depository for such global security. Ownership of beneficial interests in such global security by persons that hold through participants will be shown on, and the transfer of those ownership interests through such participant will be effected only through, records maintained by such participant. The foregoing may impair the ability to transfer beneficial interests in a global security. We will make payment of principal, premium, if any, and interest on notes represented by any such global security to the depository or its nominee, as the case may be, as the sole holder of the notes represented thereby for all purposes under the indenture. None of Regeneron, the trustee, any agent of Regeneron, or the trustee or the initial purchasers will have any responsibility or liability for any aspect of the depository's records relating to or payments made on account of beneficial ownership interests in global security representing any notes or for maintaining, supervising or reviewing any of the depository's records relating to such beneficial ownership interests. We have been advised by the depository that, upon receipt of any payment of principal, premium, if any, or interest on any global security, the depository will immediately credit, on its book-entry registration and transfer system, the accounts of participants with payments in amounts proportionate to their respective beneficial interests in the principal amount of such global security as shown on the records of the depository. Payments by participants to owners of beneficial interests in a global security held through such participants will be governed by standing instructions and customary practices as is now the case with securities held for customer accounts registered in "street name," and will be the sole responsibility of such participants. A global security may not be transferred except as a whole by the depository for such global security to a nominee of such depository or by a nominee of such depository to such depository or another nominee of such depository or by such depository or any such nominee to a successor of such depository or a nominee of such successor. If the depository is at any time unwilling or unable to continue as depository and a successor depository is not appointed by us or the depository within 90 days, we will issue notes in definitive form in exchange for the global security. In either instance, an owner of a beneficial interest in the global security will be entitled to have notes equal in principal amount to such beneficial interest registered in its name and will be entitled to physical delivery of such notes in definitive form. Notes so issued in definitive form will be issued in denominations of $1,000 and integral multiples thereof and will be issued in registered form only, without coupons. We will pay principal, premium, if any, and interest on the notes and the notes may be presented for registration of transfer or exchange, at the offices of the trustee. So long as the depository for a global security, or its nominee, is the registered owner of such global security, such depository or such nominee, as the case may be, will be considered the sole holder of the notes represented by such global security for the purposes of receiving payment on the notes, receiving notices and for all other purposes under the indenture and the notes. Beneficial interests in notes will be evidenced only by, and transfers thereof will be effected only through, records maintained by the 28 depository and its participants. The depository has nominated Cede & Co. as the nominee. Except as provided above, owners of beneficial interests in a global security will not be entitled to have the notes represented by the global security registered in their name, will not be entitled to receive physical delivery of certificated notes and will not be considered the holders thereof for any purposes under the indenture. Accordingly any such person owning a beneficial interest in such a global security must rely on the procedures of the depository, and, if any such person is not a participant, on the procedures the participant through which such person owns its interest, to exercise any rights of a holder under the indenture. The indenture provides that the depository may grant proxies and otherwise authorize participants to give or take any request, demand, authorization, direction, notice, consent, waiver or other action which a holder is entitled to give or take under the indenture. We understand that under existing industry practices, in the event that we request any action of holders or that an owner of a beneficial interest in such a global security desires to give or take any action which a holder is entitled to give or take under the indenture, the depository would authorize the participants holding the relevant beneficial interest to give or take such action and such participants would authorize beneficial owners owning through such participants to give or take such action or would otherwise act upon the instructions of beneficial owners owning through them. The depository has advised us that the depository is a limited-purpose trust company organized under the laws of the State of New York, a member of the Federal Reserve System, a "clearing corporation" within the meaning of the New York Uniform Commercial Code, and a "clearing agency" registered under the Exchange Act. The depository was created to hold the securities of its participants and to facilitate the clearance and settlement of securities transactions among its participants in such securities through electronic book-entry changes in accounts of the participants, thereby eliminating the need for physical movement of securities certificates. The depository's participants include securities brokers and dealers (including the initial purchasers), banks, trust companies, clearing corporations and certain other organizations, some of whom (and/or their representatives) own the depository. Access to the depository's book-entry system is also available to others, such as banks, brokers, dealers and trust companies, that clear through or maintain a custodial relationship with a participant, either directly or indirectly. 29

Our authorized capital stock consists of 160,000,000 shares of common stock, par value ~~$.001~~$0.001 per share, 40,000,000 shares of Class A stock, par value ~~$.001~~$0.001 per share, and 30,000,000 shares of preferred stock, par value ~~$.01~~$0.01 per share. As of December ~~31, 2001, 41,264,280~~6, 2004, 53,384,650 shares of our common stock were outstanding and held by ~~623~~621 shareholders of record and ~~2,562,689~~2,358,373 shares of our Class A stock were outstanding and held by 6356 shareholders of record. The following is a summary description of our capital stock. For more information, see our Restated Certificate of Incorporation ~~a copy of which is incorporated by reference as an exhibit to our annual report on Form 10-K for~~dated June 21, 1991 and the ~~fiscal year ended December 31, 2000. COMMON STOCK AND CLASS A STOCK~~ amendments thereto.

General. The rights of holders of common stock and holders of Class A stock are identical except for voting ~~and~~rights, conversion rights, and restrictions on transferability.

Voting Rights. The holders of Class A stock are entitled to ten votes per share and the holders of common stock are entitled to one vote per share. Except as otherwise ~~required~~expressly provided by law, orand subject to any voting rights provided to holders of preferred stock, holders of common shares have exclusive voting rights on all matters requiring a vote of shareholders. Except as ~~described below,~~provided by law, the holders of Class A stock and the holders of shares of common stock will vote together as a single class on all matters presented to the

shareholders for their vote or approval, including the election of directors. Shareholders are not entitled to vote cumulatively for the election of directors and no class of outstanding common ~~stock~~shares acting alone is entitled to elect any directors.

Transfer Restrictions. Class A stock is subject to certain limitations on transfer that do not apply to the common stock.

Dividends and Liquidation. ~~Holders~~ Except as described in this paragraph, holders of Class A stock and holders of our common stock have an equal right to receive dividends when and if declared by our board of directors out of funds legally available therefor. If a dividend or distribution payable in Class A stock is made on the Class A stock, we must also make a pro rata and simultaneous dividend or distribution on the common stock payable in shares of common stock. Conversely, if a dividend or distribution payable in common stock is made on the common stock, we must also make a pro rata and simultaneous dividend or distribution on the Class A stock payable in shares of Class A stock. In the event of our liquidation, dissolution or winding up, holders of the shares of Class A stock and common stock are entitled to share equally, share-for-share, in the assets available for distribution after payment of all creditors and the liquidation preferences of our preferred stock.

Optional Conversion Rights. Each share of Class A stock may, at any time and at the option of the holder, be converted into one fully paid and nonassessable share of common stock. Upon conversion, such shares of common stock would not be subject to restrictions on transfer that applied to the shares of Class A stock prior to conversion except to the extent such restrictions are imposed under applicable securities laws. The shares of common stock are not convertible into or exchangeable for shares of Class A stock or any other of our shares or securities.

Other Provisions. Holders of Class A stock and common stock have no preemptive rights to subscribe tofor any additional securities of any class which we may issue and there are no redemption provisions or sinking fund provisions applicable to either such class, nor ~~is the~~are our shares of Class A stock or the common stock subject to calls or assessments.

Nasdaq National Market Listing. Our common stock is quoted on the Nasdaq National Market. The current rules of the National Association of Securities Dealers, Inc. (the ~~"NASD"~~“NASD”) effectively preclude the trading or quotation through the Nasdaq National Market of any securities of an issuer which has issued securities or taken other corporate action that would have the effect of nullifying, restricting or disparately reducing the per share voting of an outstanding class or classes of equity securities registered under section 12 of the Exchange Act. Certain national securities exchanges have adopted similar rules or 30 policies. We do not intend to issue any additional shares of any stock that would make it ineligible for inclusion on the Nasdaq National Market or any national securities exchange. However, if we issue additional stock that causes us to become ineligible for continued inclusion on the Nasdaq National Market, then the ineligibility would be likely to materially reduce the liquidity of an investment in our common stock and would likely depress ~~its~~the market value of our common stock below that which would otherwise prevail.

Transfer Agent and Registrar. The ~~Transfer Agent~~transfer agent and ~~Registrar~~registrar for our common stock is American Stock Transfer & Trust Company. ~~PREFERRED STOCK~~

The following is a description of certain general terms and provisions of our preferred stock. The particular terms of any series of preferred stock will be described in a prospectus supplement and the extent, if any, to which the general provisions set forth below may apply to the series of preferred stock so offered will be described in the prospectus supplement. The following description of the preferred stock does not purport to be complete. You should refer to the provisions of our Restated Certificate of Incorporation dated June 21, 1991 and the amendments thereto, and to the Certificate of Amendment to our Restated Certificate of Incorporation relating to a specific series of preferred stock which will be in the form filed with the SEC as an exhibit to, or incorporated by reference in, the registration statement which includes this prospectus.

General. Our Restated Certificate of Incorporation allows us to issue up to 30,000,000 shares of preferred stock in one or more series and as may be determined by our board of directors. As of December 31, 2004, no shares of our preferred stock were outstanding and 100,000 shares of our Series A Junior

Participating Preferred Stock were reserved for issuance in connection with our shareholders rights plan described below. Our board of directors ~~who may~~has the authority, without shareholder consent, to establish from time to time the number of shares to be included in ~~each such~~any series of our preferred stock, to fix the designation, powers, preference, and rights of the shares of ~~each~~any such series and any qualifications, limitations or restrictions thereof and to increase or decrease the number of shares of any such series without any further vote or action by the shareholders. The rights, preferences and restrictions of the preferred stock of any series of preferred stock will be fixed by a Certificate of Amendment to our Restated Certificate of Incorporation relating to such series. A prospectus supplement relating to such series will describe the terms of the preferred stock of the series, including the following:



	•	the number of shares in that series;



	•	the designation for that series by number, letter or title that shall distinguish the series from any other series of preferred stock;



	•	the dividend rate (or method for determining the rate) for that series and whether dividends on that series of preferred stock will be cumulative, noncumulative or partially cumulative;



	•	any liquidation preference per share of that series of preferred stock;



	•	any conversion or exchange provisions applicable to that series of preferred stock;



	•	any redemption or sinking fund provisions applicable to that series of preferred stock;



	•	any voting rights of that series of preferred stock; and



	•	the terms of any other preferences or rights applicable to that series of preferred stock.

Permanent Global Preferred Securities. A series of preferred stock may be issued in whole or in part in the form of one or more global securities that will be deposited with a depositary or its nominee identified in the prospectus supplement relating to such series of preferred stock. The terms of the depositary arrangement with respect to any series of preferred stock and the rights of and limitations on owners of beneficial interests in a global security representing a series of preferred stock will be described in the related prospectus supplement.

Transfer Agent and Registrar. The transfer agent and registrar for each series of preferred stock will be set forth in the prospectus supplement.

Anti-Take-Over Effects. Our board of directors may authorize, without shareholder approval, the issuance of preferred stock with voting and conversion rights that could adversely affect the voting power and other rights of holders of our common stock. Preferred stock could thus be issued quickly with terms designed to delay or prevent a change in control or to make the removal of management more difficult. In certain circumstances, this could have the effect of decreasing the market price of our common stock. ~~REGISTRATION RIGHTS OF CERTAIN HOLDERS Certain~~

One of our shareholders ~~have~~has registration rights. Under the ~~agreements~~registration rights agreement between us and ~~the holders~~such shareholder, after March 28, 2005, such shareholder (and certain of ~~registration rights, certain holders~~its transferees) may ~~under certain circumstances~~ request that we file a registration statement under the Securities Act and, upon such request and subject to ~~certain~~ minimum size and other conditions, we will ~~generally~~ be required to use our best efforts to effect any such registration. We are not ~~generally~~ required to effect more than ~~two~~four such registrations. ~~However, we are required under certain circumstances to effect an unlimited number of Form S-3 or similar short form registrations for such holders.~~ We are generally obligated to bear the expenses, other than underwriting discounts and sales commissions, of all of these registrations. In addition, if we propose to register any of our securities, either for our own account or for the account of other shareholders, with certain exceptions, we are required to notify the holders noted above and to include in such registration all of the shares of our common stock requested to be included by such holders. In connection with this shelf registration statement, we have notified each of the holders who have registration rights and each holder, other than the selling securityholders listed in this prospectus or any supplement thereto, has either waived its rights to exercise its respective registration rights or is subject to a lock-up agreement. RIGHTS PLAN

General. In September 1996, we adopted a ~~Shareholder Rights Plan.~~shareholder rights plan. Our rights agreement provides that each of our common shares will have attached to it one right which, when exercisable, entitles the registered

holder upon exercise to purchase a unit consisting of one one-thousandth of a share of Series A junior participating preferred stock, par value $.01 per share, at aan initial purchase price of $120 per ~~unit. Initially,~~unit, subject to customary antidilution adjustments. For a description of the rights under our rights agreement are attached to outstanding certificates representing our common shares and no separate certificates representing the rights will be distributed. The rights will separate from our common shares and be represented by separate certificates approximately 10 days after someone acquires or commences a tender offer for 20%terms of our outstanding common shares. After the rights separate from our common shares, certificates representing the rights will be mailed to record holders of our common stock. Once distributed, the rights certificates alone will represent the rights. 31 All of our common shares issued prior to the date the rights separate from the common shares will be issued with the rights attached. The rights are not exercisable until the date the rights separate from the common shares. We may redeem the rights by action of the Board of Directors, at which time the rights will terminate and the holder of the rights will have only the right to receive $0.01 per right. The rights will expire automatically on October 18, 2006 unless earlier redeemed or exchanged by us. If an acquiror obtains or has the right to obtain 20% or more of our common shares, then each right will entitle the holder to purchase a number of our common shares initially equal to two times the purchase price of each right, unless the acquisition is made pursuant to a tender or exchange offer for all of our outstanding shares at a price determined by a majority of our independent directors. In this event, rights held by the acquiring person shall become null and void. In certain circumstances, a right will entitle the holder to purchase a number of shares of commonSeries A junior participating preferred stock, ~~of the acquiror having a then current market value of twice the right's purchase price.~~see “— Series A Junior Participating Preferred Stock” below. Holders of rights will have no rights as ~~our~~ shareholders, including the right to vote or receive dividends, simply by virtue of holding the rights.

Exercisability of Rights. The rights will not become exercisable until the earlier of:


	•	ten days following a public announcement that a person or group (other than specified exempted persons) has become the beneficial owner of 20% or more of our common shares then outstanding; or

	•	ten business days following the commencement of a tender or exchange offer that would result in a person or group becoming the beneficial owner of 20% or more of our common shares then outstanding.

“Flip-In” Feature. In the event a person or group (other than specified exempted persons) becomes the beneficial owner of 20% or more of our common shares then outstanding, other than pursuant to a tender or exchange offer for all outstanding common shares at a price and on other terms which a majority of our non-officer directors determine to be fair to and otherwise in the best interests of our shareholders, each right will entitle the holder (except for such person or group, whose rights will automatically become null and void) to acquire, upon exercise of the right, shares of our common stock having a value equal to twice the exercise price of the right. For example, if we assume that the initial purchase price of $120 is in effect on the date that this “flip-in” feature of the right becomes applicable, each holder of a right, except for the person or group that has become the beneficial owner of 20% or more of our common shares then outstanding, can exercise a right by paying us $120 in order to receive from us common stock having a value equal to $240.

“Flip-Over” Feature. If, after a person or group (other than specified exempted persons) becomes the beneficial owner of 20% or more of our common shares, we engage in a merger or other business combination transaction and are not the surviving corporation, engage in a merger or other business combination in which we are the surviving corporation and our common shares are changed or exchanged, or 50% or more of our assets, cash flow or earning power is sold or transferred, then each holder of a right, except for the person or group that is the beneficial owner of 20% or more of our common shares then outstanding as described above, will have the right to receive, upon exercise of the right, shares of the acquiring company’s capital stock having a value equal to twice the exercise price of the right.

Redemption of Rights. Our board of directors may redeem the rights, at a redemption price of $.01 per right, at any time prior to the earlier of:


	•	ten days following the public disclosure that a person or group (other than specified exempted persons) has become the beneficial owner of 20% or more of our common shares then outstanding, or

	•	5:00 p.m. New York City time on October 18, 2006,

~~in which event the rights will terminate and the holders of the rights will have the right to receive only the redemption price for each right held.~~

Amendment of Rights. Except as described below in this paragraph, at any time before the rights become exercisable, our rights agreement may be supplemented or amended in any manner by our board of directors without the consent of the holders of common shares. After the rights become exercisable, except as described below in this paragraph, our board of directors may supplement or amend the rights agreement to cure any ambiguity, correct any defects, shorten or lengthen any time period, or make any other change that does not adversely affect the interests of holders of the rights (other than persons or groups (excluding specified exempted persons) beneficially owning 20% or more of our outstanding common shares), except that such no supplement or amendment may lengthen a time period relating to when the rights may be redeemed at a time when the rights are not redeemable or any other time period unless the lengthening is for the purpose of protecting, enhancing or clarifying the rights of, and/or the benefits to, the holders of the rights. In addition, no supplement or amendment of the rights agreement may change the redemption price for the rights, the final expiration date for the rights of October 18, 2006, the purchase price payable to exercise a right or the

~~number of one one-thousandths of a share of Series A junior participating preferred stock for which a right is exercisable.~~

Expiration of Rights. If not previously exercised, the rights will expire at 5:00 p.m. New York City time on October 18, 2006, unless we redeem the rights earlier.

Anti-Takeover Effects. Our rights agreement may have anti-takeover effects. The rights may cause substantial dilution to a person or group that attempts to acquire us. Accordingly, the existence of the rights may deter acquirors from making takeover proposals or tender offers. However, the rights are not intended to prevent a takeover, but rather are designed to enhance the ability of our board to negotiate with an acquiror on behalf of all shareholders. The rights should not interfere with any merger or other business combination approved by our board of directors, since the ~~shareholders.~~board may redeem or amend the rights as described above, so that, in general, the rights would not be or become exercisable in connection with such an approved transaction. In addition, the rights should not interfere with a proxy contest. ~~SELLING SECURITYHOLDERS~~

Series A Junior Participating Preferred Stock. In connection with adopting our shareholder rights plan, our board of directors designated 100,000 shares of our authorized preferred stock as Series A junior participating preferred stock, none of which has been issued. Shares of our Series A junior participating preferred stock are issuable only if the rights become and continue to be exercisable, and are exercised, for Series A junior participating preferred stock in accordance with the rights agreement. If issued, each share of the Series A junior participating preferred stock:


	•	will be nonredeemable and junior to all other series of preferred stock, unless otherwise provided in the terms of those other series of preferred stock;

	•	will have a preferential quarterly dividend in an amount equal to the greater of $.01 or 1,000 times the aggregate per share amount of cash and non-cash dividends declared on our common shares;

	•	will have 1,000 votes, voting together with the common shares and any other capital stock with general voting rights; and

	•	in the event of any merger, consolidation or other transaction in which common shares are converted or exchanged, will be entitled to receive 1,000 times the amount and type of consideration received per common share.

Upon and during specified dividend arrearages, the holders of Series A Participating Preferred Stock will also have the right, voting together as a single class with any other shares of preferred stock having such arrearages, to elect two directors. Upon liquidation, the holders of Series A junior participating preferred stock will be entitled to receive an aggregate preferred liquidation payment intended to equal 1000 times the then current purchase price payable to exercise a right, plus an amount equal to accrued and unpaid dividends and distributions on the Series A junior participating preferred stock, whether or not declared, to the date of such payment. The ~~notes were originally issued~~rights of our Series A junior participating preferred stock as to dividends, liquidation and voting, and in the event of mergers and consolidations, are protected by customary antidilution provisions.

For a description of anti-takeover effects of various provisions of our charter, by-laws, our rights agreement and the New York Business Corporation Law, please see“RISK FACTORS — Risks Related To Common Stock —Our existing shareholders may be able to exert significant influence over matters requiring shareholder approval”and —“The anti-takeover effects of provisions of our charter, by-laws and our rights agreement, and of New York corporate law, could defer, delay or prevent an acquisition or other “change in control” of us and ~~sold~~could adversely affect the price of our common stock”, found on pages 11 and 12 of this prospectus, and the description of our rights plan in the immediately preceding section under the caption “Rights Plan”.

The following descriptions of the debt securities do not purport to be complete and are subject to and qualified in their entirety by ~~Merrill Lynch, Pierce, Fenner & Smith Incorporated and Robertson Stephens, Inc. (the "initial purchasers") in transactions exempt from~~reference to the indenture, a form of which has been filed with the SEC as an exhibit to the registration ~~requirements~~statement of which this prospectus is a part. Any future supplemental indenture or similar document also will be so filed. You should read the ~~Securities Act to persons reasonably believed by~~indenture and any supplemental indenture or similar document because they, and not this description, define your rights as holder of our debt securities. All capitalized terms have the ~~initial purchasers to be "qualified institutional buyers" as defined by Rule 144A under~~meanings specified in the ~~Securities Act. The selling securityholders~~indenture.

We may issue, from time to time, debt securities, in one or more series, that will consist of either our senior debt (“Senior Debt Securities”), our senior subordinated debt (“Senior Subordinated Debt Securities”), our subordinated debt (“Subordinated Debt Securities”) or our junior subordinated debt (“Junior Subordinated Debt Securities” and, together with the Senior Subordinated Debt Securities and the Subordinated Debt Securities, the “Subordinated Securities”). The debt securities we offer will be issued under an indenture between us and ~~sell pursuant~~one or more financial institutions qualified under the Trust Indenture Act to ~~this prospectus~~act as trustee. We may appoint more than one trustee under the indenture, each with respect to one or more series of debt securities. Each such trustee shall be a corporation or banking association organized and doing business in the United States that has a combined capital and surplus of at least $10,000,000. Debt securities, whether senior, senior subordinated, subordinated or junior subordinated, may be issued as convertible debt securities or exchangeable debt securities.

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit designated by us. Except for the limitations on consolidation, merger, and sale of all or substantially all of our assets contained in the ~~notes listed~~indenture, the terms of the indenture do not contain any covenants or other provisions designed to afford holders of any debt securities protection with respect to our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may, for U.S. federal income tax purposes, be treated as if they were issued with “original issue discount,” or “OID,” because of interest payment and other characteristics. Special U.S. federal income tax considerations applicable to debt securities issued with original issue discount will be described in more detail in any applicable prospectus supplement.

~~The applicable prospectus supplement for a series of debt securities that we issue will describe, among other things, the following terms of the offered debt securities:~~


	•	the title;


	•	any limit on the aggregate principal amount;


	•	whether issued in fully registered form without coupons or in a form registered as to principal only with coupons or in bearer form with coupons;

	•	whether issued in the form of one or more global securities and whether all or a portion of the principal amount of the debt securities is represented thereby;

	•	the price or prices at which the debt securities will be issued;

	•	the date or dates on which principal is payable;

	•	the place or places where and the manner in which principal, premium or interest will be payable and the place or places where the debt securities may be presented for transfer and, if applicable, conversion or exchange;

	•	interest rates, and the dates from which interest, if any, will accrue, and the dates when interest is payable;

	•	the right, if any, to extend the interest payment periods and the duration of the extensions;


	•	our rights or obligations to redeem or purchase the debt securities, including sinking fund or partial redemption payments;

	•	conversion or exchange provisions, if any, including conversion or exchange prices or rates and adjustments thereto;

	•	the currency or currencies of payment of principal or interest;

	•	the terms applicable to any debt securities issued at a discount from their stated principal amount;

	•	the terms, if any, pursuant to which any debt securities will be subordinate to any of our other debt;

	•	if the amount of payments of principal or interest is to be determined by reference to an index or formula, or based on a coin or currency other than that in which the debt securities are stated to be payable, the manner in which these amounts are determined and the calculation agent, if any, with respect thereto;

	•	if other than the entire principal amount of the debt securities when issued, the portion of the principal amount payable upon acceleration of maturity as a result of a default on our obligations;

	•	if applicable, covenants affording holders of debt protection with respect to our operations, financial condition or transactions involving us; and

	•	any other specific terms of any debt securities.

The applicable prospectus supplement will set forth certain U.S. federal income tax considerations for holders of any debt securities and the ~~shares~~securities exchange or quotation system on which any debt securities are listed or quoted, if any.

Debt securities issued by us will be structurally subordinated to all indebtedness and other liabilities of ~~common stock~~our subsidiaries, except to the extent any such subsidiary guarantees or is otherwise obligated to make payment on such debt securities. As of December 6, 2004, we have no subsidiaries.

Unless otherwise provided in the applicable prospectus supplement, all securities of any one series need not be issued ~~upon conversion~~at the same time and may be issued from time to time without consent of any holder.

~~Payment of the principal of, premium, if any, and interest on Senior Debt Securities will rank on a parity with all of our other existing and future unsecured and unsubordinated debt.~~

Payment of the principal of, premium, if any, and interest on Senior Subordinated Debt Securities will be junior in right of payment to the prior payment in full of all of our existing and future unsubordinated debt. We will set forth in the applicable prospectus supplement relating to any Senior Subordinated Debt Securities the subordination terms of such ~~notes. When we refer to the "selling securityholders" in this prospectus, we mean those persons listed in the table below,~~securities as well as the ~~pledgees, donees, assignees, transferees, successors and others who later hold any~~aggregate amount of outstanding debt, as of the ~~selling securityholders' interests. The table below sets~~most recent practicable date, that by its terms would be senior to the Senior Subordinated Debt Securities. We will also set forth ~~the name~~in such prospectus supplement limitations, if any, on issuance of ~~each selling securityholder,~~additional senior debt or additional senior subordinated debt.

Payment of the principal ~~amount at maturity~~ of, ~~notes that each selling securityholder may offer pursuant~~premium, if any, and interest on Subordinated Debt Securities will be subordinated and junior in right of payment to ~~this prospectus~~the prior payment in full of all of our senior and ~~the number of shares of common stock into which such notes are convertible. Unless~~senior subordinated debt. We will set forth ~~below,~~in the applicable prospectus supplement relating to ~~our knowledge, none~~any Subordinated Debt Securities the subordination terms of such securities as well as the aggregate amount of outstanding indebtedness, as of the ~~selling securityholders has,~~most recent practicable date, that by its terms would be senior to the Subordinated Debt Securities. We will also set forth in such prospectus supplement limitations, if any, on issuance of additional senior debt, additional senior subordinated debt or ~~within~~additional subordinated debt.

Payment of the ~~past three years has had,~~principal of, premium, if any, ~~material relationship with us or any~~and interest on Junior Subordinated Debt Securities will be subordinated and junior in right of payment to the prior payment in full of all of our ~~predecessors or affiliates or beneficially owns~~senior, senior subordinated, and subordinated debt. We will set forth in ~~excess~~the applicable prospectus supplement relating to any Junior Subordinated Debt Securities the subordination terms of 1%such securities as well as the aggregate amount of outstanding debt, as of the ~~outstanding common stock. The principal amounts~~most recent practicable date, that by its terms would be senior to the Junior Subordinated Debt Securities. We will also set forth in such prospectus supplement limitations, if any, on issuance of the notes provided in the table below is based on information provided to us by each of the selling securityholders as of January 22, 2002, and the percentages are based on $200,000,000 principal amount at maturity of notes outstanding. The number of shares of common stock thatadditional debt.

Debt securities may be ~~sold is calculated based on the current~~convertible into or exchangeable for our other securities or property. The terms and conditions of conversion ~~price of $30.2512 per share. Since the date on which each selling securityholder provided this information, each selling securityholder identified below may have sold, transferred~~ or otherwise disposed of all or a portion of its notes in a transaction exempt from the registration requirements of the Securities Act. Information concerning the selling securityholders may change from time to time and any changed informationexchange will be set forth in ~~supplements~~the applicable prospectus supplement. The terms will include, among others, the following:


	•	the conversion or exchange price;

	•	the conversion or exchange period;

	•	provisions regarding the ability of us or the holder to convert or exchange the debt securities;

	•	events requiring adjustment to the conversion or exchange price; and

	•	provisions affecting conversion or exchange in the event of our redemption of the debt securities.

We cannot consolidate or merge with or into, or transfer or lease all or substantially all of our assets to, ~~this prospectus~~any person (other than a direct or indirect wholly owned subsidiary of the Issuer) unless (a) we will be the continuing corporation or (b) the successor corporation or person to which our assets are transferred or leased is a corporation organized under the laws of the United States, any state of the United States or the District of Columbia and it expressly assumes our obligations on the debt securities and under the indenture. In addition, we cannot effect such a transaction unless immediately after giving effect to such transaction, no default or event of default under the indenture shall have occurred and be continuing. Subject to certain exceptions, when the person to whom our assets are transferred or leased has assumed our obligations under the debt securities and the indenture, we shall be discharged from all of our obligations under the debt securities and the indenture.

This covenant would not apply to any recapitalization transaction, a change of control of our company or a highly leveraged transaction, unless the transaction or change of control were structured to include a merger or consolidation or transfer or lease of all or substantially all of our assets.

~~Unless otherwise indicated, the term “Event of Default,” when used in the indenture in respect of a series of debt securities, means any of the following:~~


	•	failure to pay interest on any debt security of such series for 30 days after the date payment is due and payable, provided that an extension of an interest payment period by us in accordance with the terms of the debt securities of such series shall not constitute a failure to pay interest;

	•	failure to pay principal or premium, if any, on any debt security of such series when due, either at maturity, upon any redemption, by declaration or otherwise;

	•	failure to make sinking fund payments in respect of any debt security of such series when due;

	•	failure to perform any other covenant contained in the indenture (other than a covenant in the indenture solely for the benefit of a different series of debt securities) for 90 days after we receive


		written notice that performance is required from the trustee or the holders of at least 25% in aggregate principal amount of the debt securities of such series then outstanding;

	•	events in bankruptcy, insolvency or reorganization of our company; or

	•	any other Event of Default provided in the applicable resolution of our board of directors or the supplemental indenture under which we issue such series of debt securities.

An Event of Default for a particular series of debt securities does not necessarily constitute an Event of Default for any other series of debt securities issued under the indenture. If an Event of Default relating to the ~~extent required. In addition,~~payment of interest, principal or any sinking fund installment involving any series of debt securities has occurred and is continuing, the ~~conversion ratio, and therefore~~trustee or the ~~number~~holders of ~~shares of our common stock issuable upon conversion~~not less than 25% in aggregate principal amount of the ~~notes,~~debt securities of each affected series then outstanding may declare the entire principal of all the debt securities of that series to be due and payable immediately.

If an issuable upon conversionsuch, ~~The selling securityholders not obligated to sell conversion of the notes, shares of common stock consummation of any such sales.~~
~~NAME - ----~~ Aristeia International Limited.................... Aristeia Partners, L.P....... Baker Biotech Fund I, L.P.... Baker Biotech Fund II, L.P........................ Baker Bros. Investments, L.P........................ Baker Bros. Investments II, L.P........................ Baker/Tisch Investments, L.P........................ Calamos Investments.......... Clinton Multistrategey Master Fund, Ltd.................. Clinton Riverside Convertible Portfolio Limited.......... Common Fund Event-Driven Company.................... Continental Casualty Company.................... Deutsche Banc Alex Brown Inc........................ Fidelity Select Portfolios: Biotechnology.............. First Union International Capital Markets Inc........ Four Partners................ Fresno County Employees Retirement Association..... General Electric Pension Trust...................... Global Bermuda Limited Partnership................ Highbridge International LLC........................ Honeywell International Pension Trust.............. JP Morgan Securities Inc..... Lakeshore International, Ltd. ...................... Levco Alternative Fund, Ltd. ...................... Lawrence N. Brandt........... Lyxor Master Fund............ Merrill Lynch, Pierce, Fenner & Smith Incorporated....... Purchase Associates L.P. .... Robertson Stephens........... Royal Bank of Canada......... TQA Master Plus Fund, Ltd.... UBS O'Connor LLC............. UBS Warburg LLC..............

~~NAME - ----~~ Vanguard Equity Income Fund....................... Yield Strategies Fund I, L.P. ...................... Zurich Institutional Benchmarks................. All other holders of notes or future transferees, pledges, donees, assignees or successors of any such holders(11)(12)............ Total........................
~~- --------------- * Less than one percent (1%). (1) Assumes conversion~~ Event of Default relating to the performance of other covenants in the indenture occurs and is ~~subject to adjustment. Accordingly, the number~~continuing for a period of ~~shares~~90 days after notice of ~~common stock or if any other Event~~ of ~~the notes may increase~~Default provided in a supplemental indenture or ~~decrease. 32 may from time to time offer~~board resolution occurs and ~~sell any or~~is continuing, and such Event of Default involves all of the ~~securities under this prospectus. Because~~series of Senior Debt Securities, then the ~~selling securityholders are the notes~~trustee or the ~~shares~~holders of ~~common stock issuable upon we cannot estimate the~~not less than 25% in aggregate principal amount of the notes or how many that the selling securityholders will hold upon AGGREGATE PRINCIPAL NUMBER OF SHARES PERCENTAGE OF AMOUNT AT PERCENTAGE OF OF COMMON STOCK SHARES OF MATURITY OF NOTES NOTES THAT MAY COMMON STOCK THAT MAY BE SOLD OUTSTANDING BE SOLD(1) OUTSTANDING(2) ------------------- ------------- ---------------- ----------------- $ 5,460,000 2.73% 180,488 * $ 1,540,000 * 50,907 * $ 9,000,000 4.5% 297,508(3) * $ 9,525,000 4.76% 314,863(4) * $ 750,000 * 24,792(5) * $ 3,000,000 1.5% 99,169(6) * $ 3,000,000 1.5% 99,169(7) * $ 250,000 * 8,264 * $ 4,000,000 2.0% 132,226 * $ 7,500,000 3.75% 247,923 * $ 90,000 * 2,975 * $ 4,000,000 2.0% 132,226 * $ 18,000,000 9.0% 595,017 1.34% $ 10,000,000 5.0% 330,565 * $ 5,000,000 2.5% 165,282 * $ 20,000,000 10.0% 661,130(8) 1.49% $ 800,000 * 26,445 * $ 1,800,000 * 59,501 * $ 400,000 * 13,222 * $ 13,000,000 6.5% 429,734 * $ 1,400,000 * 46,279 * $ 12,000,000 6.0% 396,678(9) * $ 1,600,000 * 52,890 * $ 2,534,000 1.27% 83,765 * $ 1,250,000 * 41,320 * $ 188,000 * 6,214 * $ 8,775,000 4.39% 290,070 * $ 688,000 * 22,742 * $ 15,000,000 7.5% 495,847 1.12% $ 2,500,000 1.25% 82,641(10) * $ 3,750,000 1.88% 123,961 * $ 6,000,000 3.0% 198,339 * $ 3,995,000 2.0% 132,060 * 33 AGGREGATE PRINCIPAL NUMBER OF SHARES PERCENTAGE OF AMOUNT AT PERCENTAGE OF OF COMMON STOCK SHARES OF MATURITY OF NOTES NOTES THAT MAY COMMON STOCK THAT MAY BE SOLD OUTSTANDING BE SOLD(1) OUTSTANDING(2) ------------------- ------------- ---------------- ----------------- $ 6,000,000 3.0% 198,339 * $ 3,000,000 1.5% 99,169 * $ 250,000 * 8,264 * $ 13,955,000 6.98% 461,316 1.04% ------------ ----- --------- ----- $200,000,000 100% 6,611,300(13) 13.11%(14) ============ ===== ========= ===== of all of the ~~holder's notes at a conversion rate~~series of ~~33.0565 shares of common stock per $1,000~~Senior Debt Securities then outstanding (treated as one class) may declare the entire principal amount ~~at maturity~~of all of the ~~notes. This conversion rate~~series of Senior Debt Securities due and payable immediately.

Similarly, if an Event of Default relating to the performance of other covenants in the indenture occurs and is ~~subject to adjustment, however, as described under "Description~~continuing for a period of 90 days after notice of such, or if any other Event of Default provided in a supplemental indenture or board resolution occurs and is continuing, and such Event of Default involves all of the ~~Notes -- Conversion Rights." As a result,~~series of Subordinated Securities, then the ~~number~~trustee or the holders of ~~shares~~not less than 25% in aggregate principal amount of ~~common stock issuable upon conversion~~all of the ~~notes~~series of Subordinated Securities may ~~increase or decrease~~declare the entire principal amount of all of the series of Subordinated Securities due and payable immediately.

If, however, the Event of Default relating to the performance of other covenants in the ~~future. (2) Calculated based~~indenture or any other Event of Default provided in a supplemental indenture or board resolution that has occurred and is continuing is for less than all of the series of Senior Debt Securities or Subordinated Securities, as the case may be, then, the trustee or the holders of not less than 25% in aggregate principal amount of each affected series of the Senior Debt Securities or the Subordinated Securities, as the case may be, may declare the entire principal amount of all debt securities of such affected series due and payable immediately. The holders of not less than a majority in aggregate principal amount of the debt securities of a series may, after satisfying conditions, rescind and annul any of the above-described declarations and consequences involving the series.

If an Event of Default relating to events in bankruptcy, insolvency or reorganization of our company occurs and is continuing, then the principal amount of all of the debt securities outstanding under the indenture, and any accrued interest, will automatically become due and payable immediately, without any declaration or other act by the trustee or any holder.

The indenture imposes limitations on ~~Rule 13d-3(d)(i)~~suits brought by holders of debt securities against us. Except as provided below, no holder of debt securities of any series may institute any action against us under the indenture unless:


	•	the holder has previously given to the trustee written notice of default and continuance of that default;

	•	the holders of at least 25% in principal amount of the outstanding debt securities of the affected series have requested that the trustee institute the action;

	•	the requesting holders have offered the trustee reasonable indemnity for expenses and liabilities that may be incurred by bringing the action;

	•	the trustee has not instituted the action within 60 days of the request; and

	•	the trustee has not received inconsistent direction by the holders of a majority in principal amount of the outstanding debt securities of the series.

Notwithstanding the foregoing, each holder of debt securities of any series has the right, which is absolute and unconditional, to receive payment of the principal of and premium and interest, if any, on such debt securities when due and to institute suit for the enforcement of any such payment, and such rights may not be impaired without the consent of that holder of debt securities.

We will be required to file annually with the trustee a certificate, signed by an officer of our company, stating whether or not the officer knows of any default by us in the performance, observance or fulfillment of any condition or covenant of the indenture.

We may issue the debt securities of a series in whole or in part in the form of one or more fully registered global securities that we will deposit with a depositary or with a nominee for a depositary identified in the applicable prospectus supplement and registered in the name of such depositary or nominee. In such case, we will issue one or more registered global securities denominated in an amount equal to the aggregate principal amount of all of the debt securities of the series to be issued and represented by such registered global security or securities.

~~Unless and until it is exchanged in whole or in part for debt securities in definitive registered form, a registered global security may not be transferred except as a whole:~~


	•	by the depositary for such registered global security to its nominee;

	•	by a nominee of the depositary to the depositary or another nominee of the depositary; or

	•	by the depositary or its nominee to a successor of the depositary or a nominee of the successor.

The prospectus supplement relating to a series of debt securities will describe the specific terms of the depositary arrangement with respect to any portion of such series represented by a registered global security. We anticipate that the following provisions will apply to all depositary arrangements for debt securities:


	•	ownership of beneficial interests in a registered global security will be limited to persons that have accounts with the depositary for the registered global security, those persons being referred to as “participants,” or persons that may hold interests through participants;

	•	upon the issuance of a registered global security, the depositary for the registered global security will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal amounts of the debt securities represented by the registered global security beneficially owned by the participants;

	•	any dealers, underwriters or agents participating in the distribution of the debt securities will designate the accounts to be credited; and

	•	ownership of any beneficial interest in the registered global security will be shown on, and the transfer of any ownership interest will be effected only through, records maintained by the depositary for the registered global security (with respect to interests of participants) and on the records of participants (with respect to interests of persons holding through participants).

The laws of some states may require that certain purchasers of securities take physical delivery of the securities in definitive form. These laws may limit the ability of those persons to own, transfer or pledge beneficial interests in registered global securities.

So long as the depositary for a registered global security, or its nominee, is the registered owner of the registered global security, the depositary or the nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by the registered global security for all purposes under the indenture. Except as set forth below, owners of beneficial interests in a registered global security:


	•	will not be entitled to have the debt securities represented by a registered global security registered in their names;


	•	will not receive or be entitled to receive physical delivery of the debt securities in the definitive form; and

	•	will not be considered the owners or holders of the debt securities under the indenture.

Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for the registered global security and, if the person is not a participant, on the procedures of a participant through which the person owns its interest, to exercise any rights of a holder under the indenture.

We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the indenture, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take the action, and those participants would authorize beneficial owners owning through those participants to give or take the action or would otherwise act upon the instructions of beneficial owners holding through them.

We will make payments of principal and premium, if any, and interest, if any, on debt securities represented by a registered global security registered in the name of a depositary or its nominee to the depositary or its nominee, as the case may be, as the registered owners of the registered global security. None of our company, the trustee or any other agent of our company or the trustee will be responsible or liable for any aspect of the records relating to, or payments made on account of, beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to the beneficial ownership interests.

We expect that the depositary for any debt securities represented by a registered global security, upon receipt of any payments of principal and premium, if any, and interest, if any, in respect of the registered global security, will immediately credit participants’ accounts with payments in amounts proportionate to their respective beneficial interests in the registered global security as shown on the records of the depositary. We also expect that standing customer instructions and customary practices will govern payments by participants to owners of beneficial interests in the registered global security held through the participants, as is now the case with the securities held for the accounts of customers in bearer form or registered in “street name.” We also expect that any of these payments will be the responsibility of the participants.

If the depositary for any debt securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, ~~using 43,826,969~~we will appoint an eligible successor depositary. If we fail to appoint an eligible successor depositary within 90 days, we will issue the debt securities in definitive form in exchange for the registered global security. In addition, we may at any time and in our sole discretion decide not to have any of the debt securities of a series represented by one or more registered global securities. In such event, we will issue debt securities of that series in a definitive form in exchange for all of the registered global securities representing the debt securities. The trustee will register any debt securities issued in definitive form in exchange for a registered global security in such name or names as the depositary, based upon instructions from its participants, shall instruct the trustee.

We may also issue bearer debt securities of a series in the form of one or more global securities, referred to as “bearer global securities.” We will deposit these bearer global securities with a common ~~shares outstanding as~~depositary for Euroclear System and Clearstream Bank Luxembourg, Societe Anonyme, or with a nominee for the depositary identified in the prospectus supplement relating to that series. The prospectus supplement relating to a series of ~~December 31, 2001. In calculating this amount~~debt securities represented by a bearer global security will describe the specific terms and procedures, including the specific terms of the depositary arrangement and any specific procedures for ~~each holder, we treated as outstanding~~ the ~~number~~issuance of shares of common stock issuable upon conversion of all that holder's notes, but we did not assume conversion of any other holder's notes. (3) Does not include 1,042,600 shares of common stock owned by Baker Biotech Fund I, L.P.debt securities in ~~addition~~definitive form in exchange for a bearer global security, with respect to the ~~common stock into which such holder's notes are convertible. (4) Does not include 1,691,000 shares~~position of ~~common stock owned~~the series represented by ~~Baker Biotech Fund II, L.P. in addition to~~a bearer global security.

We can discharge or defease our obligations under the common stock into which such holder's notes are convertible. (5) Does not include 225,630 shares of common stock owned by Baker Bros. Investments, L.P. in addition to the common stock into which such holder's notes are convertible. (6) Does not include 80,000 shares of common stock owned by Baker Bros. Investments II, L.P. in addition to the common stock into which such holder's notes are convertible. (7) Does not include 296,150 shares of common stock owned by Baker/Tisch Investments, L.P. in addition to the common stock into which such holder's notes are convertible. (8) Does not include 2,000,000 shares of common stock owned by Four Partners in addition to the common stock into which such holder's notes are convertible. (9) Does not include 3,850 shares of common stock owned by JP Morgan Securities Inc. in addition to the common stock into which such holder's notes are convertible. (10)Does not include 10,400 shares of common stock owned by Royal Bank of Canada in addition to the common stock into which such holder's notes are convertible. (11) Information about other selling shareholders will beindenture as set forth below. Unless otherwise set forth in the applicable prospectus ~~supplements,~~supplement, the subordination provisions applicable to any Subordinated Securities will be expressly made subject to the discharge and defeasance provisions of the indenture.

We may discharge some of our obligations to holders of any series of debt securities that have not already been delivered to the trustee for cancellation and that have either become due and payable or are by their terms to become due and payable within one year (or are scheduled for redemption within one year). We may effect a discharge by irrevocably depositing with the trustee cash or U.S. government obligations, as trust funds, in an amount certified to be sufficient to pay when due, whether at maturity, upon redemption or otherwise, the principal of, premium, if ~~required. (12) Assumes~~any, and interest on the debt securities, and any mandatory sinking fund payments.

Unless otherwise provided in the applicable prospectus supplement, we may also discharge any and all of our obligations to holders of any series of debt securities at any time (“defeasance”). We also may be released from the obligations imposed by any covenants of any outstanding series of debt securities and provisions of the indenture, and we may omit to comply with those covenants without creating an Event of Default (“covenant defeasance”). We may effect defeasance and covenant defeasance only if, among other things:


	•	we irrevocably deposit with the trustee cash or U.S. government obligations, as trust funds, in an amount certified to be sufficient to pay at maturity (or upon redemption) the principal, premium, if any, and interest on all outstanding debt securities of the series; and


	•	we deliver to the trustee an opinion of counsel from a law firm to the effect that the holders of the series of debt securities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of the defeasance or covenant defeasance and that defeasance or covenant defeasance will not otherwise alter the holders’ U.S. federal income tax treatment of principal, premium, if any, and interest payments on the series of debt securities, which opinion, in the case of legal defeasance, must be based on a ruling of the Internal Revenue Service issued or a change in U.S. federal income tax law.

Although we may discharge or defease our obligations under the indenture as described in the two preceding paragraphs, we may not avoid, among other things, our duty to register the transfer or exchange of any series of debt securities, to replace any temporary, mutilated, destroyed, lost or stolen series of debt securities or to maintain an office or agency in respect of any series of debt securities.

~~The indenture provides that we and the trustee may enter into supplemental indentures without the consent of the holders of debt securities of a series to:~~


	•	secure our obligations under debt securities of such series;

	•	evidence the assumption by a successor corporation of our obligations;


	•	add covenants for the protection of the holders of debt securities of such series, and to make the occurrence or continuance of a default in any such additional covenants an Event of Default;


	•	surrender any right, power or option conferred upon us in respect of debt securities of such series;


	•	if debt securities of the series are convertible, to provide for conversion rights of holders of such debt securities if any reclassification or change of our common stock or any consolidation, merger or sale of all or substantially all of our assets occurs;


	•	make any change to comply with the Trust Indenture Act, as amended, or any requirement of the SEC in connection with the qualification of the indenture under the Trust Indenture Act of 1939, as amended;


	•	cure any ambiguity or correct any defect or inconsistency in the indenture;



	•	make any change that does not adversely affect the rights of holders of debt securities of such series in any material respect;



	•	establish the forms or terms of debt securities of any series;



	•	evidence and provide for the acceptance of appointment by a successor trustee; and



	•	to change or eliminate any provision, or to add any new provision, in respect of one or more series of securities; provided such change, elimination or addition does not apply to any outstanding security.

The indenture also provides that we and the trustee may, with the consent of the holders of not less than a majority in aggregate principal amount of debt securities of all series of Senior Debt Securities (voting as one class) or of all series of Subordinated Securities (voting as one series), as the case may be, then outstanding and affected, add any ~~other~~provisions to, or change in any manner, eliminate or modify in any way the provisions of, the indenture or modify in any manner the rights of the holders of the ~~notes~~debt securities of each such series. We and the trustee may not, however, without the consent of the holder of each outstanding debt security affected thereby:


	•	extend the final maturity of any debt security;

	•	reduce the principal amount or premium, if any, of any debt security;

	•	reduce the rate or extend the time of payment of interest on any debt security;

	•	reduce any amount payable on redemption on any debt security;

	•	change the currency in which the principal (other than as may be provided otherwise with respect to a series), premium, if any, or interest is payable in respect of any debt security;

	•	reduce the amount of the principal of any debt security issued with an OID that is payable upon acceleration or provable in bankruptcy;

	•	modify any of the subordination provisions or the definition of senior indebtedness applicable to any Subordinated Securities in a manner adverse to the holders of those securities;

	•	alter provisions of the indenture relating to the debt securities not denominated in U.S. dollars;

	•	impair the right to institute suit for the enforcement of any payment on any debt security when due; or

	•	reduce the percentage of holders of debt securities of any series whose consent is required for any modification of the indenture.

The indenture provides that there may be more than one trustee under the indenture, each with respect to one or more series of debt securities. If there are different trustees for different series of debt securities, each trustee will be a trustee of a trust under the indenture separate and apart from the trust administered by any other trustee under the indenture. Except as otherwise indicated in this prospectus or any ~~future pledges, donees, assignees, transferees~~prospectus supplement, any action permitted to be taken by a trustee may be taken by such trustee only with respect to the one or ~~successors~~more series of debt securities for which it is the trustee under the indenture. Any trustee under the indenture may resign or ~~from~~be removed with respect to one or more series of debt securities. All payments of principal of, premium, if any, and interest on, and all registration, transfer, exchange, authentication, and delivery of (including authentication and delivery on original issuance of the debt securities), the debt securities of a series (other than debt securities issued in bearer form) will be effected by the trustee with respect to that series at an office designated by the trustee in New York, New York.

The indenture contains limitations on the right of the trustee, should it become a creditor of our company, to obtain payment of claims in some cases or to realize on certain property received in respect of any such claim as security or otherwise. The trustee may engage in other transactions. If it acquires any conflicting interest relating to any duties with respect to the debt securities, however, it must eliminate the conflict or resign as trustee.

The holders of a majority in aggregate principal amount of any series of debt securities then outstanding will have the right to direct the time, method, and place of conducting any proceeding for exercising any remedy available to the trustee with respect to such series of debt securities, provided that the direction would not conflict with any rule of law or with the indenture, would not be unduly prejudicial to the rights of another holder of the debt securities, and would not involve any trustee in personal liability. The indenture provides that if an Event of Default shall occur and be known to any trustee and not be cured, the trustee must use the same degree of care as a prudent person would use in the conduct of his or her own affairs in the exercise of the trustee’s power. Subject to these provisions, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any of the holders of the ~~notes, do not beneficially own~~debt securities, unless they shall have offered to the trustee security and indemnity satisfactory to the trustee.

The indenture provides that neither our incorporator nor any ~~shares~~ of our past, present or future shareholders, officers or directors of our company or any successor corporation in their capacity as such shall have any individual liability for any of our obligations, covenants or agreements under the debt securities or the indenture.

~~The indenture and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York.~~

We may issue warrants for the purchase of debt securities, preferred stock or common stock, ~~other than the~~or any combination thereof. Warrants may be issued independently or together with debt securities, preferred stock or common stock ~~issuable upon conversion~~and may be attached to or separate from any offered securities. Warrants may be issued under warrant agreements issued to the holders thereof. Alternatively, one or more series of ~~the notes at the initial conversion rate. (13) Represents the number of shares of common stock~~warrants may be issued under a separate warrant agreement to be entered into ~~which $200,000,000 of notes would be convertible at the conversion rate described~~between us and a bank or trust company, as warrant agent. Any such warrant agent will act solely as our agent in footnote 1 above. (14) Represents the amount which the selling securityholders may sell under this prospectus divided by the sum of the common stock outstanding as of December 31, 2001 plus the 6,611,300 shares of common stock into which the notes are convertible. 34 PLAN OF DISTRIBUTION The selling securityholders will be offering and selling all of the securities offered and sold under this prospectus. We will not receive any of the proceeds from the offering of the notes or the shares of common stock by the selling securityholders. In connection with the ~~initial offering~~warrants and will not have any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. This summary of certain provisions of the ~~notes, we entered into~~warrants is not complete. For the complete terms of a ~~registration rights~~particular series of warrants, you should refer to the prospectus supplement for that series of warrants and the warrant agreement ~~dated October 17, 2001 with the initial purchasers~~for that particular series.

The prospectus supplement relating to a particular issue of ~~the notes. Securities may only be offered or sold under this prospectus pursuant~~warrants to purchase debt securities will describe the terms of the ~~registration rights agreement. However, selling securityholders~~debt warrants, including the following:


	•	the title of the debt warrants;


	•	the offering price for the debt warrants, if any;

	•	the aggregate number of the debt warrants;

	•	the designation and terms of the debt securities, including any conversion rights, purchasable upon exercise of the debt warrants;

	•	if applicable, the date from and after which the debt warrants and any debt securities issued with them will be separately transferable;

	•	the principal amount of debt securities that may be purchased upon exercise of a debt warrant and the exercise price for the warrants, which may be payable in cash, securities or other property;

	•	the dates on which the right to exercise the debt warrants will commence and expire;


	•	if applicable, the minimum or maximum amount of the debt warrants that may be exercised at any one time;

	•	whether the debt warrants, represented by the debt warrant certificates or debt securities that may be issued upon exercise of the debt warrants, will be issued in registered or bearer form;

	•	information with respect to book-entry procedures, if any;

	•	the currency or currency units in which the offering price, if any, and the exercise price are payable;

	•	the redemption or call provisions, if any, applicable to the debt warrants; and

	•	any additional terms of the debt warrants, including terms, procedures, and limitations relating to the exchange, exercise, and settlement of the debt warrants.

Debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations. Debt warrants may ~~resell all or a portion~~be exercised at the corporate trust office of the ~~securities~~warrant agent or any other office indicated in ~~open market transactions in reliance upon Rule 144~~the debt warrant certificate or ~~Rule 144A under~~ the ~~Securities Act, provided they meet the criteria and conform~~related prospectus supplement. Prior to the ~~requirements~~exercise of ~~one~~their debt warrants, holders of ~~these rules. We are registering~~debt warrants will not have any of the ~~notes~~rights of holders of the debt securities purchasable upon exercise and ~~shares~~will not be entitled to payment of principal or any premium, if any, or interest on the debt securities purchasable upon exercise.

The prospectus supplement relating to a particular series of warrants to purchase our common stock ~~covered by this prospectus~~or preferred stock will describe the terms of the warrants, including the following:


	•	the title of the warrants;

	•	the offering price for the warrants, if any;

	•	the aggregate number of the warrants;

	•	the designation and terms of the common stock or preferred stock that may be purchased upon exercise of the warrants;

	•	if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each security;

	•	if applicable, the date from and after which the warrants and any securities issued with the warrants will be separately transferable;

	•	the number of shares of common stock or preferred stock that may be purchased upon exercise of a warrant and the exercise price for the warrants;

	•	the dates on which the right to exercise the warrants shall commence and expire;

	•	if applicable, the minimum or maximum amount of the warrants that may be exercised at any one time;

	•	the currency or currency units in which the offering price, if any, and the exercise price are payable;

	•	the antidilution provisions of the warrants, if any;

	•	the redemption or call provisions, if any, applicable to the warrants; and

	•	any additional terms of the warrants, including terms, procedures, and limitations relating to the exchange, exercise, and settlement of the warrants.


	•	to vote, consent or receive dividends;

	•	receive notice as shareholders with respect to any meeting of shareholders for the election of our directors or any other matter; or

	•	exercise any rights as shareholders of our company.

We may sell debt securities, common stock, preferred stock or warrants to ~~permit holders to conduct public secondary trading~~purchase debt securities, common stock or preferred stock in one or more of ~~these securities~~the following ways from time to ~~time after~~time:


	•	to or through underwriters or dealers;

	•	by ourself directly;

	•	through agents; or

	•	through a combination of any of these methods of sale.

~~A prospectus supplement relating to an offering of offered securities will set forth the ~~date~~terms of ~~this prospectus. We have agreed, among other things,~~such offering, including:~~


	•	the name or names of any underwriters, dealers or agents;

	•	the purchase price of the offered securities and the proceeds to us from the sale;

	•	any underwriting discounts and commissions or agency fees and other items constituting underwriters’ or agents’ compensation; and

	•	any initial public offering price, any discounts or concessions allowed or reallowed or paid to dealers, and any securities exchanges on which such offered securities may be listed.

Any initial public offering prices, discounts or concessions allowed or reallowed or paid to bear all expenses, other than underwriting discounts and selling commissions, in connection with the registration and sale of the notes and the shares of common stock covered by this prospectus. The selling securityholdersdealers may ~~sell all or a portion of the notes and shares of common stock beneficially owned by them and offered hereby~~be changed from time to ~~time: - directly; or - through~~time.

If underwriters ~~broker-dealers or agents, who may receive compensation~~are used in the ~~form of discounts, commissions or concessions from~~sale, the ~~selling securityholders and/or from~~underwriters may acquire the ~~purchasers of the notes~~offered securities for their own account and ~~shares of common stock for whom they~~ may ~~act as agent. The notes and the shares of common stock may be sold~~resell them from time to time in one or more transactions, ~~at: -~~including negotiated transactions, at a fixed ~~prices, which may be changed; - prevailing market prices~~public offering price or at ~~the time of sale; -~~ varying prices determined at the time of ~~sale;~~sale. The offered securities may be offered either to the public through underwriting syndicates represented by one or ~~- negotiated prices. These prices~~more managing underwriters or by one or more underwriters without a syndicate. Unless otherwise set forth in a prospectus supplement, any obligation of the underwriters to purchase any series of securities will be ~~determined by the holders~~subject to certain conditions precedent.

In connection with underwritten offerings of the offered securities and in accordance with applicable law and industry practice, underwriters may over-allot or ~~by agreement between these holders and underwriters~~effect transactions that stabilize, maintain or ~~dealers who may receive fees or commissions in connection with~~otherwise affect the ~~sale. The aggregate proceeds to the selling securityholders from the sale of the notes or shares of common stock offered by them hereby will be the purchase~~market price of the ~~notes or shares of common stock less discounts and commissions, if any. The selling securityholders may be deemed to be "underwriters" as defined~~offered securities at levels above those that might otherwise prevail in the ~~Securities Act~~open market, including by entering stabilizing bids, effecting syndicate covering transactions or imposing penalty bids, each of ~~1933, as amended. Any profits realized by the selling securityholders may be deemed to be underwriting commissions. The sales~~which is described ~~in the preceding paragraph~~below.


	•	A stabilizing bid means the placing of any bid, or the effecting of any purchase, for the purpose of pegging, fixing or maintaining the price of a security.

	•	A syndicate covering transaction means the placing of any bid on behalf of the underwriting syndicate or the effecting of any purchase to reduce a short position created in connection with the offering.

	•	A penalty bid means an arrangement that permits the managing underwriter to reclaim a selling concession from a syndicate member in connection with the offering when offered securities originally sold by the syndicate member are purchased in syndicate covering transactions.

These transactions may be effected ~~in transactions: -~~ on ~~any national securities exchange or quotation service on which the notes or shares of common stock may be listed or quoted at the time of sale, including~~ the Nasdaq National Market, in the ~~case~~over-the-counter market or otherwise. Underwriters are not required to engage in any of these activities, or to continue such activities if commenced.

If a dealer is used in the sale, we may sell such offered securities to the dealer, as principal. The dealer may then resell the offered securities to the public at varying prices to be determined by that dealer at the time for resale. The names of the ~~shares~~dealers and the terms of ~~common stock; -~~the transaction will be set forth in the ~~over-the counter market; - in transactions otherwise than on such exchanges~~prospectus supplement relating to that transaction.

Offered securities may be sold directly by us to one or ~~services~~more institutional purchasers, or through agents designated by us, from time to time, at a fixed price or prices, which may be changed, or at varying prices determined at the time of sale. Any agent involved in the ~~over-the-counter market;~~offer or - through the writing of options. These transactions may include block transactions or crosses. Crosses are transactions in which the same broker acts as an agent on both sides of the trade. In connection with sales of the notes and shares of common stock or otherwise, the selling securityholders may enter into hedging transactions with broker-dealers. These broker-dealers may in turn engage in short sales of the notes and shares of common stock in the course of hedging their positions. The selling securityholders may also sell the notes and shares of common stock short and deliver the notes 35 and shares of common stock to close out short positions, or loan or pledge notes and shares of common stock to broker-dealers that in turn may sell the notes and shares of common stock. To our knowledge, there are currently no plans, arrangements or understandings between any selling securityholders and any underwriter, broker-dealer or agent regarding the sale of the ~~notes and the shares of common stock by the selling securityholders. Selling securityholders may not sell any, or may not sell all, of the notes and the shares of common stock~~ offered by them pursuant to this prospectus. In addition, we cannot assure you that a selling securityholder will not transfer, devise or gift the notes and the shares of common stock by other means not describedsecurities in this prospectus. In addition, any securities covered by this prospectus which qualify for sale pursuant to Rule 144 or Rule 144A of the Securities Act may be sold under Rule 144 or Rule 144A rather than pursuant to this prospectus. The notes were issued and sold in October 2001 in transactions exempt from the registration requirements of the Securities Act to persons reasonably believed by the initial purchasers to be "qualified institutional buyers," as defined in Rule 144A under the Securities Act. Pursuant to the registration rights agreement, we have agreed to indemnify the initial purchasers and each selling securityholder, and each selling securityholder has agreed to indemnify us against specified liabilities arising under the Securities Act. The selling securityholders may also agree to indemnify any broker-dealer or agent that participates in transactions involving sales of the securities against some liabilities, including liabilities that arise under the Securities Act. The selling securityholders and any other person participating in such distribution will be subject to the Exchange Act. The Exchange Act rules include, without limitation, Regulation M, which may limit the timing of purchases and sales of any of the notes and the underlying shares of common stock by the selling securityholders and any such other person. In addition, Regulation M of the Exchange Act may restrict the ability of any person engaged in the distribution of the notes and the underlying shares of common stock to engage in market-making activities with respect to the particular notes and the underlying shares of common stock being distributed for a period of up to five business days prior to the commencement of distribution. This may affect the marketability of the notes and the underlying shares of common stock and the ability of any person or entity to engage in market-making activities with respect to the notes and the underlying shares of common stock. Under the registration rights agreement, we are obligated to use our reasonable best efforts to keep the registration statement of which this prospectus is delivered will be named, and any commissions payable by us to such agent will be set forth, in the prospectus supplement relating to that offering. Unless otherwise indicated in such prospectus supplement, any such agent will be acting on a ~~part effective until~~best efforts basis for the ~~earlier of: - October 17, 2003; - the date when the notes~~period of its appointment.

Underwriters, dealers, and ~~the shares of common stock issuable upon conversion of the notes (i)~~agents may be ~~resold immediately without restriction pursuant~~entitled under agreements entered into with us to ~~the volume limitation provisions of Rule 144(k)~~indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or ~~(ii) cease~~ to contribution with respect to payments that the underwriters, dealers or agents may be ~~outstanding;~~required to make in respect thereof. Underwriters, dealers, and -agents may be customers of, engage in transactions with, or perform services for us and our affiliates from time to time in the ~~sale,~~ordinary course of business.

Other than our common stock, which is listed on the Nasdaq National Market, each of the securities issued hereunder will be a new issue of securities, will, unless otherwise indicated in the relevant prospectus supplement, have no prior trading market, and may or may not be listed on a national securities exchange or the Nasdaq National Market. Any common stock sold pursuant to the registration statement to which this prospectus relates, of all the securities registered thereunder. Our obligation to keep the registration statement to which this prospectus relates effective is subject to specified, permitted exceptions set forth in the registration rights agreement. In these cases, we may prohibit offers and sales of the notes and shares of common stock pursuant to the registration statement to which this prospectus relates. We may suspend the use of this prospectus if we learn of any event that causes this prospectus to include an untrue statement of a material fact required to be stated in the prospectus or necessary to make the statements in the prospectus not misleading in light of the circumstances then existing. If this type of event occurs, a prospectus supplement ~~or post-effective amendment, if required,~~ will be ~~distributed~~listed on the Nasdaq National Market, subject to ~~each selling securityholder. Each selling securityholder has agreed not~~official notice of issuance. Any underwriters to ~~trade~~whom we sell securities ~~from~~for public offering and sale may make a market in the ~~time the selling securityholder receives notice from us of this type of event until the selling securityholder receives a prospectus supplement or amendment. This time period~~securities, but such underwriters will not ~~exceed 45 days in~~be obligated to do so and may discontinue any ~~three-month period and~~market making at any time without notice. We cannot assure you that there will ~~not exceed an aggregate~~be a market for the offered securities.

The validity of ~~120 days in any 12 month-period. 36~~ ~~LEGAL MATTERS Certain legal matters regarding~~ the ~~notes and the shares of common stock into which those notes are convertible will be~~securities being offered hereby is being passed upon for ~~Regeneron~~us, by Skadden, Arps, Slate, Meagher & Flom LLP, ~~New York, New York.~~ Boston, Massachusetts.

The audited financial statements ~~of Regeneron Pharmaceuticals, Inc.~~ incorporated in this prospectus by reference to the Annual Report on Form ~~10-K~~10-K/A Amendment No. 2 of ~~Regeneron Pharmaceuticals, Inc.~~our company for the year ended December 31, ~~2000,~~2003, except as they relate to Amgen-Regeneron Partners for the year ended December 31, 2001, have been audited by PricewaterhouseCoopers LLP, an independent ~~accountants,~~registered public accounting firm, and insofar as they relate to Amgen-Regeneron Partners for the year ended December 31, 2001, by Ernst & Young LLP, independent auditors, whose ~~report~~reports thereon isare incorporated by reference herein. Such financial statements have been so incorporated in reliance on the ~~report~~reports of such independent ~~accountants~~registered public accounting firm and independent auditors given on the authority of such firms as experts in auditing and accounting.

The financial statements of Amgen-Regeneron Partners appearing in Regeneron Pharmaceuticals, Inc.’s Annual Report (Form 10-K/A Amendment No. 2) for the year ended December 31, 2003, have been audited by Ernst & Young LLP, independent auditors, as set forth in their report thereon included therein and incorporated herein by reference. Such financial statements are incorporated herein in reliance upon the report of Ernst & Young LLP pertaining to such financial statements given on the authority of such firm as experts in auditing and accounting. Ernst & Young LLP, independent auditors, have audited the financial statements of Amgen-Regeneron Partners included in our Annual Report on Form 10-K for the year ended December 31, 2000, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. The Amgen-Regeneron Partners' financial statements are incorporated by reference in reliance on Ernst & Young LLP's report, given on their authority as experts in accounting and auditing. 37

The following table sets forth ~~all fees and~~our expenses in connection with the ~~issuance and distribution of~~offerings described in this Registration Statement. All expenses, other than the ~~securities being registered hereby (other than underwriting discounts and commissions). All of such expenses, except the Securities and Exchange Commission~~SEC registration fee, are ~~estimated.~~ estimates.


New York		13-3444607 ~~(State~~
(State or other jurisdiction of ~~(I.R.S. Employer~~ incorporation or organization) Identification No.) 777 OLD SAW MILL RIVER ROAD TARRYTOWN, NEW YORK 10591 (914) 347-7000 (Address, including zip code and telephone number, including area code, of registrant's principal executive offices)		(I.R.S. Employee identification number)


SEC Registration Fee		$	23,540
Transfer Agents, Trustees and Depositary’s Fees, and Expenses		$	50,000
Printing and Engraving Fees and Expenses		$	100,000
Accounting Fees and Expenses		$	500,000
Stock Exchange Listing Fees		$	50,000
Legal Fees		$	500,000
Rating Agency Fees		$	150,000
Miscellaneous		$	50,000

	Total	$	1,423,540


Exhibit
No.			Description

	1	.1**	Form of underwriting agreement.

	4	.1	Restated Certificate of Incorporation of Regeneron Pharmaceuticals, Inc.(1)

	4	.2	Certificate of Amendment of the Certificate of Incorporation of Regeneron Pharmaceuticals, Inc.(2)

	4	.3	Certificate of Amendment of the Certification of Incorporation of Regeneron Pharmaceuticals, Inc.(3)

	4	.4	Bylaws of Regeneron Pharmaceuticals, Inc.(4)

	4	.5	Amendment to the Bylaws of Regeneron Pharmaceuticals, Inc.(5)

	4	.6	Form of indenture.

	4	.7**	Supplemental indenture or other instrument creating a series of debt securities under the indenture.

	4	.8**	Form of any debt security.

	4	.9**	Form of preferred stock.

	4	.10**	Form of any preferred stock certificate.

	4	.11**	Form of warrant agreement.

	4	.12**	Form of warrant certificate.

	4	.13	Rights Agreement, dated as of September 20, 1996, between Regeneron Pharmaceuticals, Inc. and Chase Mellon Shareholder Services LLC, as Rights Agent, including the form of Rights Certificate as Exhibit B thereto.(6)

	4	.14	Registration Rights Agreement, dated as of March 28, 2003, by and between Novartis Pharma AG and Regeneron Pharmaceuticals, Inc.(7)

	4	.15	Stock Purchase Agreement, dated as of September 5, 2003, by and between Aventis Pharmaceuticals Inc. and Regeneron Pharmaceuticals, Inc.(8)

	4	.16	Form of certificate of shares of common stock.

	5	.1	Opinion of Skadden, Arps, Slate, Meagher & Flom LLP as to the legality of the debt securities, common stock, preferred stock, and warrants.

	8	.1**	Opinion of counsel as to certain tax matters.

	12	.1*	Statement re: computation of ratios of earnings to combined fixed charges of Regeneron Pharmaceuticals, Inc.

	23	.1	Consent of PricewaterhouseCoopers LLP, Independent Registered Public Accounting Firm.

	23	.2	Consent of Ernst & Young LLP, Independent Auditors.

	23	.3	Consent of Skadden, Arps, Slate, Meagher & Flom LLP (included in Exhibit 5.1).
	24	.1*	Power of Attorney of certain officers and directors of Regeneron Pharmaceuticals, Inc.
	25	.1	Statement of Eligibility and Qualification of trustee under the Indenture for Regeneron Pharmaceuticals, Inc. (to be filed in accordance with the Undertaking set forth in Section 512(j) of Regulation S-K under the Securities Act of 1933, as amended).


	Murray A. Goldberg
	Senior Vice President, Finance & Administration
	Chief Financial Officer,
	Treasurer and Assistant Secretary



/s/ MURRAY A. GOLDBERG Murray A. Goldberg				Senior Vice President, Finance ~~January 22, 2002 - ---------------------------------------------------~~ & Administration, Chief ~~Murray A. Goldberg~~ Financial Officer, Treasurer and Assistant Secretary ~~(Principal~~ (Principal Financial Officer) *

/s/ DOUGLAS S. MCCORKLE Douglas S. McCorkle				Controller and Assistant ~~January 22, 2002 - ---------------------------------------------------~~ Treasurer ~~(Principal Douglas S. McCorkle~~ (Chief Accounting Officer)

* ~~Director January 22, 2002 - ---------------------------------------------------~~ P. Roy Vagelos, M.D.				Chairman of the Board

* Charles A. Baker				Director

* ~~Director January 22, 2002 - ---------------------------------------------------~~ Michael S. Brown, M.D.				Director

* ~~Director January 22, 2002 - ---------------------------------------------------~~ Alfred G. Gilman, M.D.~~, Ph.D.~~				Director

* ~~Director January 22, 2002 - ---------------------------------------------------~~ Joseph L. Goldstein, M.D.				Director

* Arthur F. Ryan				Director ~~January 22, 2002 - ---------------------------------------------------~~


ABOUT THIS PROSPECTUS		i
WHERE YOU CAN FIND MORE INFORMATION		i
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS		ii
REGENERON PHARMACEUTICALS, INC		1 Risk Factors................................................ 5 Ratio of Earnings to Fixed Charges.......................... 14 Use of Proceeds............................................. 14 Dividend Policy............................................. 14 Description of the Notes.................................... 15
RISK FACTORS		2
USE OF PROCEEDS		13
RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS		13
DESCRIPTION OF SECURITIES		13
	Description of Capital ~~Stock................................ 30 Selling Securityholders..................................... 32 Plan~~Stock	13
	Description of ~~Distribution........................................ 34 Legal Matters............................................... 36 Experts..................................................... 36~~ Debt Securities	18
	Description of Warrants	26
PLAN OF DISTRIBUTION		28
LEGAL MATTERS		29
EXPERTS		29
FORM OF INDENTURE
FORM OF CERTIFICATE OF SHARES OF COMMON STOCK
OPINION OF SKADDEN, ARPS, SLATE, MEAGHER & FLOM LLP
CONSENT OF PRICEWATERHOUSECOOPERS LLP
CONSENT OF ERNST & YOUNG LLP


	*We have had a history of operating losses and we may never achieve profitability. If we continue to incur operating losses, we may be unable to continue our operations.*


	*We will need additional funding in the future, which may not be available to us, and which may force us to delay, reduce or eliminate our product development programs or commercialization efforts.*


	We have a significant amount of debt and may have insufficient cash to satisfy our debt service and repayment obligations. In addition, the amount of our debt could impede our operations and flexibility.


	*Successful development of any of our product candidates is highly uncertain.*


	Clinical trials required for our product candidates are expensive and time-consuming, and their outcome is highly uncertain. If any of our drug trials are delayed or achieve unfavorable results, we will have to delay or may be unable to obtain regulatory approval for our product candidates.


	*The development of serious or life-threatening side effects with any of our product candidates would lead to delay or discontinuation of development, which could severely harm our business.*


	*Our product candidates in development are recombinant proteins that could cause an immune response, resulting in the creation of harmful or neutralizing antibodies against the therapeutic protein.*


	A previous phase 3 study evaluating AXOKINE demonstrated modest average weight loss over a 12-month period. In addition, a completed phase 2 study evaluating the IL-1 Trap in patients with rheumatoid arthritis failed to achieve its primary endpoint.


	*If we do not obtain regulatory approval for our product candidates, we will not be able to market or sell them.*


	If the testing or use of our products harms people, we could be subject to costly and damaging product liability claims. We could also face costly and damaging claims arising from employment law, securities law, environmental law or other applicable laws governing our operations.


	Our operations may involve hazardous materials and are subject to environmental, health, and safety laws and regulations. We may incur substantial liability arising from our activities involving the use of hazardous materials.


	On February 27, 2004, Novartis Pharma AG provided notice to us that they would not participate in the continued development and commercialization of the IL-1 Trap under our collaboration agreement. This may harm our ability to develop and commercialize the IL-1 Trap.


	If our collaboration with Aventis Pharmaceuticals, Inc. for the VEGF Trap is terminated, our business operations and our ability to develop, manufacture, and commercialize the VEGF Trap in the time expected, or at all, would be harmed.


	*Our collaborators and service providers may fail to perform adequately in their efforts to support the development, manufacture, and commercialization of our drug candidates.*


	*We have limited manufacturing capacity, which could inhibit our ability to successfully develop or commercialize our drugs.*


	*If any of our clinical programs are discontinued, we may face costs related to the unused capacity at our manufacturing facilities.*


	*Certain of our raw materials are single-sourced from third parties; third-party supply failures could adversely affect our ability to supply our products.*


	If we are unable to establish sales, marketing, and distribution capabilities, or enter into agreements with third parties to do so, we will be unable to successfully market and sell future products.


	*We may be unable to formulate or manufacture our product candidates in a way that is suitable for clinical or commercial use.*


	*Even if our product candidates are ever approved, their commercial success is highly uncertain because our competitors may get to the marketplace before we do with better or lower cost drugs.*


	*The successful commercialization of our product candidates will depend on obtaining coverage and reimbursement for use of these products from third-party payors.*


	*We are dependent on our key personnel and if we cannot recruit and retain leaders in our research, development, manufacturing, and commercial organizations, our business will be harmed.*


	*If we cannot protect the confidentiality of our trade secrets or our patents are insufficient to protect our proprietary rights, our business and competitive position will be harmed.*


	*We may be restricted in our development and/or commercialization activities by third party patents.*


	*Future sales of our common stock by our significant shareholders or us may depress our stock price and impair our ability to raise funds in new share offerings.*


	*Our existing shareholders may be able to exert significant influence over matters requiring shareholder approval.*


	The anti-takeover effects of provisions of our charter, by-laws and our rights agreement, and of New York corporate law, could deter, delay or prevent an acquisition or other “change in control” of us and could adversely affect the price of our common stock.


	*Anti-Takeover Effects of Provisions of the Charter and By-Laws, the Rights Agreement, and New York corporate law*


	*No Individual Liability of Incorporators, Shareholders, Officers or Directors*