To Evaluate the Efficacy and Safety of AK111 Injection in the Treatment of Moderate to Severe Plaque Psoriasis

This is a randomized, double-blind phase II clinical study to evaluate the efficacy and safety of AK111 in the treatment of subjects with moderate to severe plaque psoriasis. The study has 2 parts: first part (randomized double-blind) and second part (open).

Inclusion criteria

• Male or female subjects aged ≥18 years old.
• Subjects with moderate to severe plaque psoriasis with or without psoriatic arthritis.
• At screening and baseline, PASI score ≥ 12, BSA ≥ 10%, sPGA ≥ 3.
• Suitable for systematic therapy assessed by investigators.
• Subjects who are women of childbearing potential must be practicing an adequate, medically acceptable method of birth control during the study and for at least 6 months after the last investigational drug administration.

Exclusion criteria

• Types of psoriasis other than chronic plaque-type psoriasis.
• Drug-induced psoriasis.
• Evidence of active TB. Patients with evidence of latent tuberculosis may enter the trial after sufficient treatment had initiated and maintained according to protocol.
• Positive results of confirmatory test for hepatitis B, hepatitis C, human immunodeficiency virus (HIV) or syphilis.
• History of repeated chronic infection, had any serious infection or systemic infection within 2 months before screening.
• Progressive or uncontrolled symptoms or signs of circulatory, respiratory, digestive, neuropsychiatric or psychological,hematological, endocrine and other systems before randomization.
• History of malignant tumour within 5 years before screening.
• Previous or current autoimmune diseases.
• Allergic to any component of the investigational drug, or have had severe allergic reactions to monoclonal antibodies.