There were 2 cohorts of participants. Cohort 1 was a single dose study of ARQ-151 0.5% cream applied to 25 cm^2 of psoriatic plaque(s) in 8 psoriasis participants. Cohort 2 was a parallel group, double blind, vehicle controlled study in which ARQ-151 cream 0.5%, ARQ-151 cream 0.15% or vehicle cream was applied once a day for 28 days to participants with between 0.5% to 5.0% BSA of chronic plaque psoriasis. Participants were adult (≥18 years old) males or females with chronic plaque psoriasis.
This study assessed the safety and pharmacokinetics (PK) of a single dose application of ARQ-151 cream 0.5% to 25 cm^2 of psoriatic plaque(s) (Cohort 1). The study also assessed the safety, PK and efficacy of ARQ-151 cream 0.5% vs vehicle and ARQ-151 cream 0.15% vs vehicle applied once a day for 28 days to individuals with 0.5% to 5.0% body surface area (BSA) of chronic plaque psoriasis (Cohort 2).