Open Label Study to Evaluate the Safety and Efficacy of AK101 Injection Subcutaneously in Subjects With Psoriasis

This is an open-label, single-arm, multi-center phase III study. The purpose of this study is to evaluate the long-term safety and efficacy of AK101 injection in subjects with moderate-to-severe plaque psoriasis. Subjects who have completed the previous Akeso registration trial with AK101 injection (AK101-302) and subjects who are to be newly enrolled will both receive AK101 135mg injection subcutaneously.

Key Inclusion Criteria:

• Applicable for subjects who have completed the previous Akeso trial (AK101-302) with AK101 injection:

• Subjects can continue to participate in this study based on assessment of investigator.
• Subjects voluntarily participate in this study.
• Subjects who are women of childbearing potential must be practicing an adequate, medically acceptable method of birth control during the treatment period and for at least 6 months after the last study drug administration.
• Applicable for subjects newly enrolled:

• Male or female subjects aged ≥ 18 years old.
• Subjects diagnosed with moderate-to-severe plaque psoriasis and are applicable to systematic treatment.
• At screening and baseline, PASI score ≥ 12, Body Surface Area BSA (BSA) ≥ 10%, sPGA ≥ 3.
• Subjects who are applicable for biological agents, based on the assessment of investigator.
• 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.

Key Exclusion Criteria:

• Applicable for subjects who have completed the previous Akeso trial (AK101-302) with AK101 injection:

• Subjects who have severe AE or SAE occurred in an Akeso trial with AK101 injection.
• Subjects who used prohibited drugs in an Akeso trial with AK101 injection.
• Subjects performed poor compliance in an Akeso trial with AK101 injection, based on the assessment of investigator.
• Subjects with any other disease, abnormal physical examination or abnormal laboratory examination leading to inapplicable for participating this study, based on the assessment of investigator.
• Applicable for subjects newly enrolled:

• Forms of psoriasis other than chronic plaque-type psoriasis.
• 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.
• Positive results of confirmatory test for hepatitis B, hepatitis C, human immunodeficiency virus (HIV) or syphilis.
• History of repeated chronic infection, had any serious infection or systemic infection within 2 months before screening.
• History of prohibited psoriasis treatments within 2/4 weeks before randomization.
• History of IL-12/23 or IL-23 inhibitors therapy.
• Inadequate washout period of prior biological therapy.
• History of malignant tumour within 5 years before screening.
• 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.