A Pilot Study of Alefacept for the Treatment of Pityriasis Rubra Pilaris

Inclusion Criteria: * Subjects may be male or female, 30 years old or older at time of consent * Have a diagnosis of pityriasis rubra pilaris at least 6 months prior to administration of the first dose of the study medication * Be a candidate for systemic therapy * Women of childbearing potential and all men must use adequate contraceptive measures if sexually active. Examples include abstinence, oral contraceptives or other form of hormonal contraception, intrauterine devices, surgical sterilization, or barrier forms of contraception with spermicidal jelly. Subjects must agree to continue to use these contraceptive measures and agree not to become or plan a pregnancy within 12 months of the date of the last study drug administration. * Agree to adhere to the study visit schedule and protocol requirements, including blood draws and clinical photographs. * Must be able to give informed consent, and this consent must be obtained prior to any study related procedures being performed. * Must avoid other treatment modalities during the course of the study and adhere to standard washout periods for any medications used to treat their skin prior to receiving the first dose of study medication. * Must agree not to receive a live viral or bacterial vaccine during the course of the study or for 12 months after the date of the last study drug administration. * Have screening blood tests that are stable as deemed by the physician investigator. AST, ALT and alkaline phosphatase levels must be within 2.0 times the upper limit of normal to participate. Exclusion Criteria: * Subjects are pregnant or planning a pregnancy (both men and women) while enrolled in the study. * Have used the medication alefacept in the past. * Have used another investigational medication within the past 4 weeks or within 5 times the half-life of that investigational medicine. * Have received systemic medications that could affect pityriasis rubra pilaris within 4 weeks of administration of the first dose of the study medicine. * Have used topical medications that could affect pityriasis rubra pilaris within 2 weeks of administration of the first dose of the study medicine. * Have received a live viral or bacterial vaccine within 3 months of administration of the first dose of the study medicine. * Have a history of chronic or recurrent infections of the skin or internal organs. * Have had a serious infection requiring hospitalization or intravenous antibiotics within 2 weeks of administration of the first dose of the study medicine. * Have a history of latent untreated tuberculosis. * Have a known history of human immunodeficiency virus (HIV), hepatitis B or hepatitis C virus. * Have a history of a malignancy except for squamous cell or basal cell carcinoma of the skin or cervical carcinoma in situ that has been treated with no evidence of recurrence. * Have a known hypersensitivity to any component of alefacept. * Have a known substance abuse problem or is deemed by the investigator as unable to follow the study protocol. * Is participating in another study for an investigational agent or procedure during the course of this study.