This study is designed to assess the safety and pharmacokinetics (PK) of a single dose application of ARQ-151 cream 0.5% to 25 cm2 of psoriatic plaque(s) (Cohort 1). The study will also assess the safety, PK and efficacy of different doses and multiple applications of ARQ-151 cream 0.5% vs placebo and ARQ-151 cream 0.15% vs placebo applied once a day for 28 days to individuals with 0.5% to 5.0% body surface area (BSA) of chronic plaque psoriasis
There are 2 cohorts of subjects. Cohort 1 is a single dose study of ARQ-151 0.5% cream applied to 25 cm2 of psoriatic plaque(s) in up to 8 psoriasis subjects. Cohort 2 is a parallel group, double blind, vehicle controlled study in which ARQ-151 cream 0.5%, ARQ-151 cream 0.15% or vehicle cream is applied once a day for 28 days to subjects with between 0.5% to 5.0% BSA of chronic plaque psoriasis. Including both Cohorts, a total of up to 92 subjects will be enrolled at 8 study sites in Canada and the US. Subjects will be adult (≥18 years old) males or females with chronic plaque psoriasis.