BIIB Company Profile

Our sales and marketing efforts are generally focused on specialist physicians in private practice or at major medical centers. We utilize common pharmaceutical company practices to market our products and to educate physicians, including sales representatives calling on individual physicians and distributors, advertisements, professional symposia, direct mail, selling initiatives, public relations and other methods. We have also established uninsured patient programs in the U.S.' for our marketed products which provide qualified patients with products at no charge. We also provide certain customer service and other related programs for our products, such as disease and product-specific websites, insurance verification services and order, delivery and fulfillment services.

Competition in the biotechnology and pharmaceutical industries is intense and comes from many and varied sources. We do not believe that any of the industry leaders can be considered dominant in view of the rapid technological change in the industry. We experience significant competition from specialized biotechnology firms in the U.S., the EU and elsewhere and from many large pharmaceutical, chemical and other companies.

AVONEX

AVONEX competed in the U.S. and EU markets primarily with three products:

''BETASERON', sold by Berlex in the U.S. and sold under the name BETAFERON' by Schering A.G.

''REBIF', which is co-promoted by Serono, Inc. and Pfizer in the U.S. and sold by Serono AG in the EU.

''COPAXONE' glatiramer acetate, sold by Teva Neuroscience, Inc. in the U.S. and co-promoted by Teva and Aventis Pharma in the EU.

RITUXAN is typically used after patients fail to respond or relapse after treatment with traditional radiation therapy or standard chemotherapy regimes, such as CVP and CHOP. ZEVALIN is typically used after patients fail to respond or relapse following treatment with RITUXAN. ZEVALIN competes with BEXXAR' (tositumomab, iodine I-131 tositumomab), a radiolabeled molecule developed by Corixa Corporation and GlaxoSmithKline. BEXXAR received FDA approval in June 2003 to treat patients with CD20+, follicular, NHL, with and without transformation, whose disease is refractory to RITUXAN and has relapsed following chemotherapy.

AMEVIVE

AMEVIVE competes with several different types of therapies including:

''traditional therapies for moderate-to-severe chronic plaque psoriasis, such as oral retinoids, steroids, methotrexate, cyclosporin, PUVA and UVB radiation.

''RAPTIVA' (efalizumab), a drug co-developed by Genentech and Xoma Corporation that was approved by the FDA in November 2003 to treat moderate-to-severe psoriasis. Serono has an exclusive license to RAPTIVA in the EU and other countries and has filed for regulatory approval of the drug in the EU. Drugs approved for other indications that are used to treat psoriasis. Among these drugs are ENBREL' (etanercept), REMICADE' (infliximab)'and HUMIRA'(adalimumab). ENBREL is sold by Amgen, Inc. and Wyeth Pharmaceuticals, Inc. and is approved to treat psoriatic arthritis. In January 2003, Amgen announced positive results from a Phase'3 clinical study of ENBREL in the treatment of moderate-to-severe plaque psoriasis and is conducting a second Phase'3 clinical study in psoriasis. REMICADE is sold worldwide by Centocor, Inc., a subsidiary of Johnson'& Johnson, as a treatment for other indications, including rheumatoid arthritis, and is currently in a Phase'2 proof of concept study as a potential treatment for psoriasis. HUMIRA is sold by Abbott Laboratories and is approved to treat rheumatoid arthritis. Abbott is undertaking clinical trials in psoriasis and psoriatic arthritis.