This study is a randomized, double-blind, placebo-controlled, multicenter clinical trial of about 70 subjects with moderate to severe plaque psoriasis.

Successfully screened subjects will be randomized in a ratio of 2:2:2:1 and stratified to previous biologics use for psoriasis.

After a 4-week screening period (day -28-0), subjects will be randomly assigned to treatment for 12 weeks.

Clinical psoriasis area and severity index (PASI), Physician's Global Assessment (PGA), dermatological Quality of Life Index (DLQI), physical exams and Laboratory tests will be performed at baseline, the end of weeks 4, 8 and 12 respectively.

Inclusion Criteria:

• Have had a diagnosis of moderate to severe plaque psoriasis for at least 6 months prior to Baseline;
• Subjects with moderate to severe plaque psoriasis covering ≥10% BSA, with a PASI ≥12 and sPGA score ≥3 at Baseline;
• Able and willing to give written informed consent.

Exclusion Criteria:

• Other types of psoriasis (such as erythrodermic psoriasis, pustular psoriasis, guttate psoriasis, etc.);
• Current drug-induced psoriasis, e.g., a new onset of psoriasis or an exacerbation of psoriasis induced by beta blockers, calcium channel blockers, antimalarial drugs or lithium;
• History or symptoms of malignancy in any organ system regardless of treatment, and regardless of evidence of recurrence or metastasis;
• Any uncontrolled clinically significant laboratory abnormality that would affect interpretation of study data or the subject's participation in the study.