This is a retreatment, multicenter, randomized, double-blind, placebo-controlled clinical study to evaluate the safety and efficacy of Benvitimod cream, 1% twice daily for the retreatment of mild to moderate stable psoriasis vulgaris in adults. Approximately 390 participants with mild to moderate stable psoriasis vulgaris will be enrolled and randomly divided into two groups in a 2:1 ratio. They will use either the Benvitimod cream or placebo at the skin with psoriasis vulgaris for 12 weeks.

This is a retreatment, multicenter, randomized, double-blind, placebo-controlled clinical study to evaluate the safety and efficacy of Benvitimod cream, 1% twice daily for the retreatment of mild to moderate stable psoriasis vulgaris in adults. Approximately 390 participants with mild to moderate stable psoriasis vulgaris will be enrolled and randomly divided into two groups in a 2:1 ratio. They will use either the Benvitimod cream or placebo at the skin with psoriasis vulgaris for 12 weeks.

The primary objective is to evaluate the efficacy and safety of Benvitimod cream in the long-term (intermittent) treatment of mild to moderate psoriasis vulgaris. The primary endpoint is proportion of participants with ≥75% improvement in Psoriasis Area and Severity Index (PASI) score 12 weeks after retreatment with Benvitimod cream or placebo.

The study is anticipated to last from April 2022 to August 2023 with 390 participants recruited form about 20 centers in China. All the related investigative organization and individuals will obey the Declaration of Helsinki and Chinese Good Clinical Practice standard. The study has been approved by Institutional Review Board (IRB) and Ethics Committee (EC) in Peking University People's Hospital.

Inclusion Criteria:

• Age 18~65 years.
• Patients who were treated with Benvitimod cream and have discontinued medication were again diagnosed as suitable for treatment with Benvitimod cream.
• The participant with diagnosis of mild to moderate stable psoriasis vulgaris:
• BSA < 10%.
• PGA ≥ 2.
• Capable of giving written informed consent.

Exclusion Criteria:

• ALT/AST > 3 ULN, BUN/Cr > 1.5 ULN.
• Skin lesions were limited to head，face and skin folds.
• Women who are pregnant, breast-feeding, or planning to become pregnant.
• Known to be allergic to active ingredients or any of the components of the drug.
• Alcoholic, or regular use of Chinese herbs or sedatives, sleeping pills, tranquilizers and other addictive drugs.
• Subjects who have other conditions that may interfere with the evaluation of the efficacy of psoriasis and/or other serious skin diseases other than psoriasis.
• Subjects who have serious diseases of the central nervous system, cardiovascular system, kidney, liver, digestive tract, respiratory system, metabolism and skeletal muscle system.
• Subjects who were considered unsuitable to participate in the study by the investigators.
• Received uv phototherapy, photochemotherapy, or systemic therapy (e.g., systemic glucocorticoid, methotrexate, retinoic acid, or cyclosporine) within 4 weeks prior to baseline visit.
• Received topical anti-psoriasis therapy (including topical glucocorticoids, retinoids, vitamin D analogues, or calcineurin inhibitors) within 2 weeks prior to baseline visit, except where the site of administration was not the target lesion after enrollment.