Biogen, Inc. (NASDAQ/BGEN) said today that it has reached a settlement in its long-standing litigation with Berlex Laboratories over a claim that the manufacture of AVONEX® (Interferon beta-1a) infringes Berlex’s “McCormick” patents. Certain settlement terms are contingent on the outcome of an appeal filed by Berlex that is currently pending. The final hearing on the appeal was held on November 7, 2001, and a decision will be issued when the court completes deliberations.

In the settlement, Biogen will receive a fully paid up, royalty-free, non-exclusive license under the patents held by Berlex in return for a payment to Berlex of $20 million. A second and final payment from Biogen to Berlex would be due if the Court of Appeals were to reverse the District Court’s previous ruling granting summary judgment in favor of Biogen.

If the Court of Appeals were to rule against Biogen and return the case to the District Court, Biogen believes that decision likely would require it to make a second and final payment of $55 million to Berlex. In the event that the ruling is significantly adverse to Biogen, the final payment would be $230 million. However, Biogen believes this possibility is remote. Biogen believes the lower court’s determination of non-infringement is sound and that it has a strong case for the Court of Appeals to affirm the lower court’s ruling. As part of this settlement, the companies agreed not to pursue further litigation about these patents.

Biogen has taken a $20 million charge against earnings in its fourth quarter 2001 results, booked against “Other Income and Expense,” consistent with U.S. GAAP under FASB Statement No. 5.

In addition to historical information, this press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Reference is made in particular to forward-looking statements regarding final resolution of litigation and the Company’s expectations as to the likelihood and amount of a final payment to Berlex, if any. These statements are based on the Company’s current beliefs and expectations as to such future outcomes. Factors which could cause actual results to differ materially from the Company’s current expectations as to such future outcomes include the risk that the court will view the merits of the case in a different manner than the Company and therefore make a determination or decision adverse to the Company on appeal, thereby requiring the Company to make the final payment and establishing the amount of such payment.

Biogen, Inc., winner of the U.S. National Medal of Technology, is a biopharmaceutical 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 international sales of AVONEX® (Interferon beta-1a) for treatment of relapsing forms of multiple sclerosis, and from the worldwide sales by licensees of a number of products, including alpha interferon and hepatitis B vaccines and diagnostic products. (Please see full prescribing information at 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