This study adopted a multicenter, randomized, double-blind, placebo-controlled phase II/III operation seamless adaptive design, aiming to evaluate the efficacy, safety and tolerability of CMS-D001 tablets in the treatment of patients with moderate to severe plaque psoriasis. The trial consists of two parts, including the Phase II clinical research stage and the Phase III clinical research stage.

In the Phase II clinical research stage, a multi-center, randomized, double-blind, placebo-controlled design will be adopted, with a planned enrollment of 120 participants. After providing written informed consent and completing all screening evaluations, eligible participants will be randomly assigned in a 1:1:1 ratio to Trial Group 1, Trial Group 2, and the placebo group, with 40 participants in each group.All randomly assigned participants will undergo a 12-week double-blind treatment and continue to be followed up until the 16th week. The study is divided into three phases: the screening period (up to 4 weeks), the treatment period (12 weeks, approximately 85 ± 3 days), and the follow-up period (2 weeks after the last dose).

In the Phase III clinical research stage, a multi-center, randomized, double-blind, placebo-controlled design will be adopted. It is planned to continue enrolling participants in the Phase III study after the completion of the Phase II clinical trial enrollment, based on the Phase II dose groups (or the recommended dose groups determined based on the Phase II study results) and the placebo group. A total of 420 participants are planned to be enrolled. After providing written informed consent and completing all screening evaluations, eligible participants will be randomly assigned in a 2:2:1 ratio to the CMS-D001 tablet 50 mg QD, 100 mg QD, and placebo control groups. Each treatment group will have a maximum of 168 participants (excluding those who switch from the placebo group), and the placebo group will have a maximum of 84 participants.The research was divided into 4 phases, namely the screening phase (up to 4 weeks), the base phase (16 weeks), the expansion phase (36 weeks), and the follow-up phase (4 weeks after the last administration).

Inclusion Criteria:

• Aged 18-75 years, willing to sign the ICF
• Diagnosed with plaque psoriasis for at least 6 months prior to screening.
• At screening and baseline, PASI score ≥ 12 points, BSA ≥ 10%, sPGA ≥ 3
• Be eligible for phototherapy or systemic therapy.

Exclusion Criteria:

• Non-plaque psoriasis (ie, guttate, pustular, erythrodermic, or inverse psoriasis) within 3 months prior to baseline.
• Other skin diseases at screening or baseline Drug-induced psoriasis.
• History of severe herpes zoster or severe herpes simplex or current herpes simplex/zoster infection.
• History of a serious bacterial, fungal, or viral infection requiring hospitalization or intravenous antimicrobial therapy within 3 months prior to the first dose.
• History of a bacterial, fungal, or viral infection requiring oral antimicrobial therapy within 4 weeks prior to the first dose.
• Active infection or acute illness within 7 days prior to the first dose. Chronic or recurrent infectious diseases at screening or baseline that, in the investigator's judgment, may increase safety risks.
• Evidence of active TB. Patients with evidence of latent tuberculosis may enter the trial after sufficient treatment had initiated and maintained according to protocol.
• History of a major or unstable clinical condition within 6 months prior to the first dose, which would compromise participation.
• History of malignant tumour within 5 years before screening.
• Previous or current autoimmune diseases.
• Positive results of confirmatory test for hepatitis B, hepatitis C, human immunodeficiency virus (HIV) or syphilis.
• Allergic to any component of the investigational drug.