REGENERON SELLS $200M OF CONVERTIBLE SENIOR SUBORDINATE NOTES.

Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN), Tarrytown, N.J. has entered into a purchase agreement providing for the sale of $200 million aggregate principal amount of convertible senior subordinated notes due 2008, reflecting an increase in the size of the offering from $150 million.

In addition, the company has granted the initial purchasers an option to purchase an additional $50 million in principal amount of notes. The notes will accrue interest at a rate of 5.50% per year and will be convertible into shares of Regeneron common stock at a conversion price of $30.25. The notes are redeemable by the company at any time if certain conditions are satisfied. 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, and is expected to close on or about October 17, 2001. Regeneron expects to use the net proceeds from this offering for development of its drug candidates, expansion of its 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.

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.

For more information, call 914/345-7641 or visit http://www.regn.com.