This is a randomized, double-blind, placebo-controlled, multicentered phase III clinical study to evaluate the efficacy and safety of AK101 in the treatment of subjects with moderate-to-severe plaque psoriasis.

This is a randomized, double-blind, placebo-controlled, multicenter phase III clinical study. The purpose of this study is to evaluate the efficacy and safety of AK101 in the treatment of subjects with moderate-to- severe plaque psoriasis. Subjects will be randomized to receive AK101 or placebo injection subcutaneously, and follow up to week 16.

Inclusion Criteria:

1. Male or female subjects aged ≥ 18 years.
2. Subjects diagnosed with moderate-to-severe plaque psoriasis for at least 6 months before screening.
3. At screening and baseline, PASI score ≥ 12, Body Surface Area BSA (BSA) ≥ 10%, sPGA ≥ 3.
4. Subjects with a history of an inadequate response, intolerable or medically inappropriate use of systemic therapy and/or phototherapy.
5. Subjects who are women of childbearing potential must have a negative pregnancy test at screening and must be practicing an adequate, medically acceptable method of birth control for at least 6 months after the last study drug administration.

Exclusion Criteria:

1. Forms of psoriasis other than chronic plaque-type psoriasis.
2. History or evidence of active TB. Patients with evidence of latent tuberculosis may enter the trial after sufficient treatment had initiated and maintained according to protocol.
3. Positive results of confirmatory test for hepatitis B, hepatitis C, human immunodeficiency virus (HIV) or syphilis.
4. History of repeated chronic infection, had any serious infection or systemic infection within 2 months before screening.
5. History of prohibited psoriasis treatments within 2/4 weeks before randomization.
6. History of IL12/23 or IL-23 inhibitors therapy.
7. Inadequate washout period of prior biological therapy.
8. History of malignant tumour within 5 years before screening.
9. Any medical or psychiatric condition, laboratory, or ECG parameter which, in the opinion of the Investigator would place the subject at risk, interfere with participation or interpretation of the study.