Study of the Clinical Activity, Safety, and Tolerability of SRT2104 in Subjects With Moderate to Severe Plaque-Type Psoriasis

This double-blind, placebo-controlled study will be conducted at 5 study centers in the United States. Approximately 30 subjects with moderate to severe plaque-type psoriasis will take part. The study will consist of a screening period of up to 21 days, a 12-week treatment period with 7 on-treatment clinic visits (approximately one every 2 weeks) and a post-dosing follow-up clinic visit approximately 30 days after the last dose of study drug is taken. Subjects will be randomized to receive either 250mg, 500mg or 1000mg of study drug or placebo. Study drug will be taken by mouth on a full stomach, every day for 84 days. Vital signs, clinical laboratory results (hematology, chemistry, and urinalysis), ECGs and physical examinations will be assessed at periodic intervals from Day 1 through Day 84. A skin biopsy will be taken at the beginning and the end of the dosing period to evaluate any effects of the study drug on psoriasis. Investigators will perform other psoriasis evaluations (including the Psoriasis Area and Severity Index \[PASI\] and the Physician's Global Assessment \[PGA\] at 5 different times throughout the study to quantify the effects of SRT2104 on psoriasis activity. Subjects will complete questionnaires throughout the study, to document their sense of well-being and mood at 4 different times during the study. Five blood samples will be obtained at different timepoints during the study, to measure the amount of SRT2104 in the body.