BIOGEN ANNOUNCES MEETING OF FDA ADVISORY COMMITTEE TO REVIEW AMEVIVE® (alefacept) FOR TREATMENT OF PSORIASIS

Biogen, Inc. (NASDAQ/BGEN) today announced that the U.S. Food and Drug Administration (FDA) will convene a Dermatologic and Opthalmic Drugs Advisory Committee on May 23, 2002 to review the registrational filing of Biogen’s drug AMEVIVE® (alefacept) for the treatment of moderate-to-severe chronic plaque psoriasis.

Biogen filed its application for AMEVIVE on August 6, 2001 in both the U.S. and in Europe.

Biogen, Inc., winner of the U.S. National Medal of Technology, is a biotechnology company principally engaged in discovering and developing drugs for human healthcare through genetic engineering. Headquartered in Cambridge, MA, the Company’s revenues are generated from worldwide sales of AVONEX for treatment of relapsing forms of multiple sclerosis, and from the sales by licensees of a number of products. (Please see full prescribing information at http://www.avonex.com.) Biogen’s research and development activities are focused on novel products to treat inflammatory and autoimmune diseases, neurological diseases, cancer, fibrosis and congestive heart failure. The Company maintains active clinical research programs in protein therapeutics, small molecules, genomics and gene therapy. For copies of press releases and additional information about the Company, please consult Biogen’s homepage on the World Wide Web at http://www.biogen.com.