Trials with a new, first-in-class drug will be done to ascertain safety, tolerability, absorption and other effects in the treatment of psoriasis, such as effects on biomarkers. Approximately 60 adult patients with psoriasis covering at least 3 percent of their body surface area will be recruited for the study. They will be randomly assigned to one of 5 treatment arms each patient has an equal chance of receiving the placebo, 50 mg, 100 mg, 200 mg, or 300 mg dose. Patients will receive study medication in a blinded fashion, i.e, the patient, the doctor and the study sponsor will not know what group the patient is in until all patients complete the study. Patients will take the medication daily for 12 weeks. The study will be enrolled in two enrollment groups of about 30 patients each, so that extent of side effects can be ascertained and expectations on their extent confirmed. The investigator and the sponsor will monitor the study for the occurrence of possible side effects. In addition to a screening visit, patients will have visits every week for the first month, and then every two weeks until 12 weeks of treatment. At 12 weeks, there are 2 visits on consecutive days for tests and there is one followup visit 4 weeks after the last dose of study drug is taken.