Astellas Pharma US, Inc. and Biogen Idec Inc. entered an agreement for Astellas to purchase the worldwide rights to Amevive (alefacept) was executed as of March 31, 2006. Amevive is a biologic anti-inflammatory compound used in the treatment of moderate-to-severe plaque psoriasis.

Under the terms of the agreement, Astellas would acquire the worldwide rights to Amevive in all indications from Biogen Idec. Biogen Idec would continue to manufacture Amevive and supply product to Astellas. The parties anticipate closing the transaction as early as mid-April.

"The acquisition of a well-established product such as Amevive strengthens our North American Dermatology franchise and provides Astellas an opportunity to continue offering physicians this effective option for the treatment of moderate-to-severe plaque psoriasis," stated William Fitzsimmons, Senior Vice President, Business Development at Astellas Pharma US, Inc.

Psoriasis is a chronic but treatable autoimmune skin disease. Roughly two percent of the world's population has psoriasis. In the US, psoriasis affects 4.5-6 million people, and about 1.2 million people have a moderate to severe form of chronic plaque psoriasis. While psoriasis is not typically life threatening, it can greatly affect appearance, self-esteem, and quality of life. Chronic plaque psoriasis can develop anywhere on the skin, though it usually appears on the scalp, knees, elbows, and trunk.