There's new hope for 1-1/2-million Americans suffering from psoriasis, an autoimmune skin disease.The U.S. Food and Drug Administration has approved Amevive (alefacept) to treat moderate-to-severe chronic plaque psoriasis in adult patients who are candidates for systemic therapy or phototherapy.

Amevive, developed by Biogen, is the first biologic medicine approved to treat psoriasis.The National Psoriasis Foundation calls it a treatment breakthrough.Amevive was specifically designed to target the underlying cause of psoriasis -- an immune system dysfunction that drives skin cells to multiply uncontrollably.

In psoriasis, skin cells grow ten times faster than the normal rate.The excess cells pile up on the skin's surface, forming red, raised, scaly plaques that can be painful and disfiguring.For some people, the disease can be so physically and emotionally disabling that they are unable to walk, miss work and become shut-ins.