BIOGEN LICENSES ORAL PSORIASIS THERAPY FROM FUMAPHARM AG

Phase III Clinical Program Expected to Begin in 2004

Biogen, Inc. (NASDAQ/BGEN) today announced it has licensed from Fumapharm AG exclusive rights to develop and market a new oral therapy for psoriasis entering Phase III clinical trials in Europe. The product is a second-generation fumarate derivative with an immunomodulatory mechanism of action. A first-generation product is currently marketed as FUMADERM® in Germany, where it is the leading prescription for oral systemic treatment of moderate-to-severe psoriasis.

Under the agreement, Biogen will receive worldwide development and marketing rights, excluding Germany. Financial terms of the agreement were not released.

Fumapharm has completed a Phase II clinical trial of the second-generation product in psoriasis. Results of this double blind, multi-center study will be announced at an upcoming dermatology conference. Biogen plans to collaborate with Fumapharm to accelerate the Phase III clinical development and registration program worldwide.

“This license agreement is one more step in continuing to strengthen and expand our pipeline in our core biologic and therapeutic areas of focus,” said James C. Mullen, Chairman and CEO of Biogen. “Our understanding of autoimmune diseases is a company strength and through the development and launch of the first biologic treatment approved for psoriasis, we have gained a keen scientific understanding of the disease and built a strong commercial foundation for bringing dermatology products to market. The success of FUMADERM in Germany as the leading oral systemic treatment for psoriasis is very encouraging. Bringing this innovative therapy forward is one more step Biogen can take toward improving the lives of people coping with this chronic disease.”

“Twenty years following the establishment of Fumapharm AG, and nine years after approval of FUMADERM in Germany, Fumapharm has partnered with Biogen – one of the most innovative and leading companies in the worldwide pharmaceutical market – on the further development of our improved fumarate derivative,” said Dr. Hans Peter Strebel, President and CEO of Fumapharm.

“Biogen and Fumapharm will work closely together to fully utilize the potential of this promising product with the goal of providing a successful therapy directed initially to treat psoriasis patients worldwide. This license agreement provides not only the resources, but also combines the know-how necessary to conduct all stages of research, development and marketing. Fumapharm and Biogen are well under way to define the future together,” Dr. Strebel said.

About Biogen
Biogen is the world’s oldest independent biotechnology company and a leader in biologics research, development and manufacturing. A pioneer in leading edge research in immunology, neurobiology and oncology, Biogen brings novel therapies to improve patients’ lives around the world through its global marketing capabilities. For press releases and additional information, please visit http://www.biogen.com.

About Fumapharm AG
Fumapharm is a privately held pharmaceutical company headquartered in Lucerne, Switzerland. FUMADERM® is the leading oral prescription drug for systemic treatment of moderate-to-severe psoriasis in Germany. For more information, please visit http://www.fumapharm.ch.

Safe Harbor
This press release contains forward-looking statements regarding the clinical and therapeutic expectations for Fumapharm’s product. These statements are based on our current beliefs and expectations. They are subject to the risks inherent in drug development, including the risks that the effects of the product in larger clinical trials may not be as expected or that there may be safety issues or other problems or delays that arise during clinical trials, unexpected technical or manufacturing hurdles, or intellectual property disputes. Drug development involves a high degree of risk. Only a small number of research and development programs result in the commercialization of a product. Success in animal models or early stage clinical trials does not ensure that later stage or larger scale clinical trials will be successful. For more detailed information on the risks and uncertainties associated with these forward looking statements and Biogen’s other activities see the Outlook section in MD&A; of Biogen’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q filed with the SEC. Biogen does not undertake any obligation to publicly update any forward-looking statements.

Media Contact:
Amy Ryan
Associate Director, Public Affairs
Biogen, Inc.
Tel: (617) 914-6524

Investment Community Contact:
Elizabeth Woo
Senior Director, Investor Relations
Biogen, Inc.
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