1 SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) OCTOBER 12, 2001 ---------------- REGENERON PHARMACEUTICALS, INC. ------------------------------------------- (Exact name of registrant as specified in its charter) NEW YORK 0-19034 No. 13-3444607 ------------------------------------------- (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number) Identification No.) 777 OLD SAW MILL RIVER ROAD, TARRYTOWN, NY 10591-6707 ----------------------------------------------------------------- (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code (914) 347-7000 -------------- NOT APPLICABLE ---- --------------- (Former name or former address, if changed since last report) Page 1 of 5

2 INFORMATION TO BE INCLUDED IN REPORT ------------------------------------ ITEM 5. OTHER EVENTS. On October 12, 2001, the Company issued a press release, a copy of which is included as an exhibit to this filing. ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS. (c) Exhibits 99(a) Press Release dated October 12, 2001. -2-

3 SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. REGENERON PHARMACEUTICALS, INC. By: /s/ Stuart Kolinski ------------------------------------ Stuart Kolinski Vice President & General Counsel Date: October 12, 2001 -3-

1 FOR IMMEDIATE RELEASE --------------------- REGENERON ANNOUNCES OFFERING OF CONVERTIBLE SENIOR SUBORDINATED NOTES IN A 144A OFFERING Tarrytown, NY - (October 12, 2001) -- Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) announced today that subject to market and other conditions, it intends to offer approximately $150 million of seven-year convertible senior subordinated notes. These notes will be convertible into shares of Regeneron common stock. The offering will be made by means of an offering memorandum to qualified institutional buyers pursuant to Rule 144A of the Securities Act of 1933, as amended. The offering is expected to close on or about October 17, 2001. Regeneron expects to use the net proceeds from this offering for preclinical and clinical development, expansion of manufacturing facilities, research, working capital, and general corporate purposes. The notes and the common stock issuable upon conversion of the notes have not been registered under the Securities Act or applicable state securities laws, and may not be offered or sold absent registration under the Securities Act and applicable state securities laws or applicable exemptions from registration requirements. Regeneron will file a registration statement for the resale of the notes and the shares of common stock issuable upon conversion of the notes within 90 days after the closing of the offering. This press release shall not constitute an offer to sell or the solicitation of an offer to buy the notes, nor shall there be any sale of the notes in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such state. The press release is being issued pursuant to and in accordance with Rule 135(c) of the Securities Act.

2 Regeneron is a biopharmaceutical company that discovers, develops, and intends to commercialize therapeutic drugs for the treatment of serious medical conditions. Regeneron's platform technologies include Targeted Genomics(TM), Functionomics(TM), and Designer Protein Therapeutics(TM). Regeneron has drugs in clinical trials for the potential treatment of obesity and rheumatoid arthritis, and has preclinical development programs in cancer, asthma, allergies, and other diseases and disorders. This news release discusses historical information and includes forward-looking statements about Regeneron and its products, programs, finances, and business, all of which involve a number of risks and uncertainties, such as risks associated with preclinical and clinical development of drugs and biologics, determinations by regulatory and administrative governmental authorities, competitive factors, technological developments, the availability and cost of capital, the costs of developing, producing, and selling products, the potential for any collaboration agreement to be canceled or to terminate without any product success, and other material risks. A more complete description of these risks can be found in Regeneron's filings with the United States Securities and Exchange Commission, including its Form 10-K for the year ended December 31, 2000. Regeneron does not undertake any obligation to update publicly any forward-looking statement, whether as a result of new information, future events, or otherwise, unless required by law. ### Contact: Charles Poole Vice President, Investor Relations Regeneron Pharmaceuticals, Inc. charles.poole@regn.com (914) 345-7641

3 Additional information about Regeneron and recent news releases are available on Regeneron's Worldwide Web Home Page at www.regn.com. Fax copies of news releases can be obtained from Regeneron's News-on-Demand Service by dialing (800) 311-0841.