This is a multicenter, randomized, double-blind, placebo-controlled phase Ⅱ study to evaluate the efficacy and safety of three different doses of SYHX1901 tablets compared with placebo in the treatment of moderate to severe plaque psoriasis. The total duration of the study will be 20 weeks which will be comprised of: a screening period (4 weeks); an efficacy assessment period (12 weeks) and a follow-up assessment period (4 weeks). Eligible subjects will be randomly assigned to SYHX1901 60 mg qd, 90 mg qd, 180 mg qd or placebo group at a 1:1:1:1 ratio for continuous oral administration for 12 weeks. The presence or absence of treatment with biological agents will be a stratification factor. Subjects will be monitored for the safety throughout the study.
The purpose of this study is to evaluate the efficacy and safety of different doses of SYHX1901 tablets in the treatment of moderate to severe plaque psoriasis in order to select doses for further clinical trials.