Efficacy and Safety of Prurisol Administered Orally for Active Mild to Moderate Chronic Plaque Psoriasis

Inclusion Criteria: * Male or non-pregnant female adults aged 18 years with a clinical diagnosis of stable (at least 6 months) plaque psoriasis, not including scalp or intertriginous areas. * The extent of psoriasis must meet all of the following three (3) criteria: * Total Body Surface Area (BSA) affected by plaque psoriasis of 10% to 20% inclusive * Investigator's Global Assessment (IGA) score of the severity of psoriasis of 2 or 3 (5- point ordinal scale) * Identification of a target psoriatic lesion with a score of 3 on the Target Lesion Assessment scale (5-point ordinal scale) for Scaling. (Other psoriatic lesions may have lower scaling scores.) * Females of reproductive potential must not be pregnant * Female subjects with reproductive potential, if sexually active, must agree to use reliable means of contraception * The subject must agree to avoid prolonged exposure to the sun and avoid the use of tanning booths or other ultraviolet light sources during the study. * The subject must provide signed and dated written informed consent to participate in the clinical study. Exclusion Criteria: * 1\. Females of reproductive potential who are not using reliable contraception. * Presence of any non-psoriatic uncontrolled (in the Investigator's medical opinion) systemic disease. i * Unstable forms of psoriasis, e.g. guttate, erythrodermic, exfoliative, palmoplantar, nail, or pustular. * Use within 6 months of biologic treatment for psoriasis * Use within 24 months of chemotherapy or radiation therapy. * Use within 2 months of any systemic immunosuppressive therapy. * Use within 1 month of (1) systemic corticosteroids, (2) systemic antibiotics, (3) systemic antipsoriasis treatments (e.g. methotrexate, corticosporin, hydroxyurea), (4) PUVA therapy, (5) UVB, (6) systemic anti-inflammatory treatment. * Use within 2 weeks of topical antipsoriasis drugs or topical corticosteroids or topical retinoids. * Presence of a condition (e.g., history of frequent consumption of substantial quantities of alcohol, or an untreated psychiatric condition) that makes it unlikely that the requirements of the protocol will be completed. * History of any previous use of a Tumor Necrosis Factor (TNF) blocker or other immunomodulating drug as therapy for psoriasis within the 6 months prior to screening. * History of any allergic reaction to any formulation of abacavir. * Previous treatment with any abacavir-containing product, e.g., Ziagen®, Epzicom®, or Trizivir®.