A Study to Assess the Efficacy and Safety of Alefacept in Psoriasis Patients for Whom Conventional Treatment is Ineffective or Inappropriate

Inclusion Criteria:

Diagnosis of Chronic Plaque Psoriasis involving ≥ 10% body surface area
Treatment history for Psoriasis in which 3 or more conventional anti-psoriatic therapies are inappropriate or ineffective
CD4+ T lymphocyte counts at or above the lower limit of normal

Exclusion Criteria:

Clinically significant abnormal hematology values or blood chemistry values
AST or ALT ≥ 3x the upper limit of normal
Other types of Psoriasis
Serious infection within the 3 months prior to the first dose of study drug
History of drug or alcohol abuse within the past 2 years
Antibody positive for HIV
History of malignancy
History of any clinically significant cardiac, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, renal, and/or other major disease
Exposure to psoriasis-modifying phototherapy or high-potency topical corticosteroid therapy within 2 weeks prior to the first dose of study drug
Exposure to systemic anti-psoriatic therapy , topical immunomodulators or topical CNIs within 4 weeks prior to the first dose of study drug
Current treatment with any therapy for tuberculosis
Previous exposure to Alefacept
Nursing mothers, pregnant women, and women planning to become pregnant during the study