IBI112 in Moderate to Severe Plaque Psoriasis With Randomized Withdrawal and Re-treatment

Inclusion Criteria: 1. Have a diagnosis of plaque-type psoriasis for at least 6 months; 2. Psoriasis Area and Severity Index (PASI) score of 12 or greater, AND static Physician's Global Assessment (sPGA) score of 3 (moderate) or greater; Psoriasis covering at least 10% of body surface area; 3. Must be a candidate for either systemic therapy or phototherapy for psoriasis. Exclusion Criteria: 1. Has any condition that, in the opinion of the investigator, would make participation not be in the best interest (for example, compromise the well-being) of the participant or that could prevent, limit, or confound the protocol-specified assessments 2. Participants who have ever received IBI112 or IL-23 inhibitor 3. History or current signs or symptoms of severe, progressive, or uncontrolled renal, hepatic, cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, or metabolic disturbances 4. Has any condition that, in the opinion of the investigator, would make participation not be in the best interest of the participant 5. Is pregnant, nursing, or planning a pregnancy (both men and women) within 6 months following the last administration of the study drug