A Randomized, Double-Blind, Vehicle-Controlled, Multicenter, Dose-Ranging, Phase 2 Study to Evaluate the Efficacy and Safety of Different Doses of ZL-1102 Topical gel (A Human VH IL-17A Antibody Fragment) in the Treatment of Chronic Plaque Psoriasis

This is a randomized, double-blind, vehicle-controlled, dose-ranging, phase 2 study of ZL-1102 in patients with chronic plaque psoriasis. Approximately 250 patients will be randomized at a ratio of 1:1:1:1:1 to 5 treatment arms for 16 weeks of treatment.

Inclusion Criteria:

1. Adults ≥ 18 years of age.

2. Willing and able to provide signed and dated informed consent prior to any study-related procedures, and willing and able to comply with all study procedures

3. Clinical diagnosis of psoriasis vulgaris of at least 6 months duration as determined by Investigator via medical records or in medical history obtained from the patient, is currently eligible for topical treatment and meets all the following criteria at screening and baseline:

   1. IGA ≥ 2 (5 score system)
   2. Affected BSA 3%-15% (excluding head)

4. Agree not to have prolonged sun exposure (e.g., recreational) during the study period. Tanning bed use or use of other light-emitting diodes (LEDs) is not allowed.

Exclusion Criteria:

1. Other types of psoriasis dominant other than plaque psoriasis (e.g., psoriatic arthritis, pustular, erythrodermic, guttate, palmar, plantar, scalp or nail disease) or the lesion is not eligible for topical treatment only.

2. Patients with any serious medical/psychiatric condition or clinically significant laboratory abnormality that would prevent study participation or place the patient at significant risk, as determined by the Investigator.

3. Known or suspected:

   1. Severe renal insufficiency or hepatic insufficiency.
   2. History of severe depression or suicidal ideation or behavior within 2 years prior to screening.

4. Positive for any of the following tests at screening:

   1. Human immunodeficiency virus (HIV): HIV antibody
   2. Hepatitis B virus (HBV): hepatitis B surface antigen (HBsAg)/hepatitis B core antibody (HBcAb)/HBV DNA
   3. Hepatitis C virus (HCV): HCV RNA

5. Patients with active tuberculosis (TB) or untreated latent TB per local guidelines.

6. History of and/or concurrent condition of inflammatory bowel disease (IBD) (ulcerative colitis and Crohn's disease), or signs/symptoms of IBD at screening that, in the opinion of the Investigator, pose an unacceptable risk to the patient if participating in the study.

7. History of and/or concurrent condition of serious hypersensitivity (anaphylactic shock or anaphylactoid reaction) to IL-17 antibodies and any human or humanized biological agents.

8. Patients who have a history of malignancy unless deemed cured by adequate treatment with no evidence of recurrence for ≥ 3 years before the initiation of study treatment.

9. Patients with a history of chronic alcohol or drug abuse within 6 months of the initiation of study treatment, as determined by the Investigator.

10. Prior exposure to ZL-1102.

11. Patients who have received a live vaccine within 6 weeks prior to dosing on Day 1.

12. Females who are pregnant, wishing to become pregnant during the study, or are breastfeeding