The study was terminated early due to insufficient subject enrolment in order to meet the primary and secondary endpoints

The study is a prospective, multi-centre, observational study designed to assess the long-term effectiveness and safety of alefacept in subjects with moderate to severe chronic plaque psoriasis.

Study includes a bio-marker sub-study to determine differences in responders vs. non-responders. Additional consent is required for the sub-study.

Inclusion Criteria:

• Subjects with moderate to severe chronic plaque psoriasis who receive a new prescription for alefacept

Exclusion Criteria:

• Subjects with a contraindication to alefacept
• Subjects with a history of cancer except for adequately treated basal cell carcinoma (maximum of 2 lesions)
• Subjects with any active cancer, including skin cancer
• Subjects having a serious local infection (eg. cellulitis, abscess) or serious systemic infection (eg. pneumonia, septicemia, tuberculosis), within the 3 months prior to the first dose of alefacept.
• Subjects known to be infected with the AIDS virus

Canadian subjects with moderate to severe chronic plaque psoriasis for which Amevive is clinically indicated