A Study to Explore Efficacy and Safety of ASP015K in Subjects With Moderate to Severe Psoriasis

A Phase 2a, Randomized, Double-blind, Placebo-Controlled, Sequential Group, Multiple-Dose Escalation Study to Evaluate the Efficacy and Safety of ASP015K in Subjects With Moderate to Severe Plaque Psoriasis

The purpose of this study is to explore the efficacy and safety of multiple, escalating doses of ASP015K when compared to placebo in subjects with moderate to severe plaque psoriasis.

Following completion of at least 1 week of study drug for all subjects in group 1, the Sponsor will review the safety information of these subjects prior to enrolling off-treatment subjects into the next dose group. Dose escalation will continue in this manner (unless stopping criteria are met) until all groups have completed the study.

Inclusion Criteria:

• Subject has moderate to severe plaque psoriasis for 6 months or longer with at least 10% Body Surface Area (BSA) affected
• Subject must be a candidate for phototherapy and/or systemic therapy

Exclusion Criteria:

• Subject has non-plaque psoriasis or drug-induced psoriasis
• Subject is on systemic psoriasis therapy within 56 days or 5 half-lives, whichever is longer, prior to first dose of study drug
• Subject has a positive TB skin test within 3 months of screening or at screening
• Subject has an abnormal chest x-ray