A Phase 3 Study of Recombinant Anti-IL-17A Humanized Monoclonal Antibody in Chinese Participants with Moderate-to-Severe Plaque Psoriasis

Inclusion Criteria:

• Must be 18 Years to 75 Years, both male and female.

• Chronic plaque psoriasis (PSO) for at least 6 months prior to the Randomization.

• Psoriasis Area Severity Index (PASI) >=12 and body surface area (BSA) affected byPSO >=10% and Static Physician Global Assessment (sPGA) score >=3.

• According to the judgment of the investigator, the subject needs to receive systemictreatment and / or phototherapy (including subjects who have used local treatment,and / or phototherapy, and / or poor control of previous systemic treatment).

• Fertile female subjects and male subjects (and their female partners) must takeeffective contraceptive measures within at least 6 months from the screening periodto the last medication. The subjects have no fertility, sperm donation and eggdonation plans within at least 6 months from the screening period to the lastmedication.

Exclusion Criteria:

• Forms of psoriasis other than chronic plaque-type (e.g., pustular, erythrodermicand/or guttate psoriasis) at screening or baseline.

• Drug-induced psoriasis.

• Ongoing use of prohibited treatments.

• Have previously received any drug that directly targets IL-17 or IL-17 receptor, orIL-12 / IL-23, or IL-23.

• Biological agents or their biological analogues were used before randomization,including but not limited to: Etanercept < 28 days; Infliximab, adalimumab or afacet <60 days; Golimumab <90 days; Or other biological agents < 5 half lives.

• Pregnant or lactating women.