The purpose of the study is to better understand the mechanism of action of an FDA approved drug (alefacept). Subjects enrolled will be given alefacept 7.5 mg intravenously on a weekly basis for 12 weeks. Response is assessed by improvement in the PASI score. The responders will get no further treatment and the nonresponders will receive additional 4 weeks of therapy. Skin biopsies will be obtained throughout the study and T-cell apoptosis will be correlated to clinical response. There is no placebo group. The duration of the study is approximately 1 year.
To determine the mechanism of action of alefacept in patients with psoriasis.