A Phase II Efficacy and Safety Study of HSK44459 in Subjects With Moderate to Severe Plaque Psoriasis

Inclusion Criteria: * Fully understand and voluntarily participate this trial, and sign the informed consent form; * Age≥18 years, regardless of gender; * Plaque psoriasis; * A candidate for systemic therapy; * Agree to use a highly effective method(s) of from the signing of the informed consent form to 3 months post-treatment. Exclusion Criteria: * Can not discontinue the prohibited medications specified in the protocol before the first dose and throughout the entire study period; * Laboratory abnormalities with clinical significance; * Forms of psoriasis other than chronic plaque-type; * Presence of other dermatological or autoimmune diseases; * Presence of active infection requiring systemic therapy; * Has undergone or plans to undergo major surgery; * History of cardiovascular or cerebrovascular diseases; * History of suicide attempts or major psychiatric disorders; * History of malignant tumors; * History of gastrointestinal surgery or diseases that may have impact on the study; * History of drug abuse, illicit drug use, or alcohol abuse; * History of severe drug allergies; * Pregnant or lactating women; * Subjects with any other factor considered by the investigator to be ineligible for participation in the trial.