Dose Ranging Study of the Safety and Efficacy of R115966 in Plaque Psoriasis

A Randomized, Evaluator-Blind, Placebo-Controlled, Parallel-Group Dose-Ranging Study of the Safety and Efficacy of Oral R115866 and R115866 Placebo in the Treatment of Plaque Psoriasis

Eligible subjects will be randomly assigned to one of three dose regimens of oral R115866 or placebo for the treatment of severe plaque psoriasis for 12 twelve weeks. The safety and efficacy of R115866 will be evaluated during the treatment period and the 8-week post treatment follow-up period.

Inclusion Criteria:

• Plaque Psoriasis with PASI greater than or equal to 10
• Male or a female who was NOT of childbearing potential (i.e., post- menopausal for greater than 12 months or had a complete hysterectomy);

Exclusion Criteria:

• Spontaneously improving or rapidly deteriorating plaque psoriasis
• Guttate, pustular, erythrodermic, or other non-plaque form of psoriasis
• Subject was under treatment for a heart disorder or had a history of cardiovascular disease (excluding effectively controlled hypertension)
• Any acute psychiatric condition, including an increased risk for suicide attempt, based on medical and psychiatric history
• Previous use of a psoriasis vaccine or had participated in an investigational study of a psoriasis vaccine
• Previous use of systemic immunomodulatory therapy known to affect psoriasis and to typically decrease immune cell populations
• Previous use of any systemic immunomodulatory therapy known to affect psoriasis and NOT typically to decrease immune cell populations
• Previous use of any photo-therapy (including laser), photo-chemotherapy, or systemic psoriasis therapy (such as systemic corticosteroids, methotrexate, retinoids, or cyclosporine) within the previous four weeks
• Pregnant or a nursing mother
• Significant coexisting hepatic, renal, or bone marrow disease, hyperlipidemia, chronic pancreatitis, osteoporosis, cancer (except non-melanoma skin cancer), a positive test for human immunodeficiency virus (HIV), a history indicating adrenal cortex dysfunction