A Study to Evaluate the Safety and Efficacy of AK120 in Subjects With Moderate to Severe Atopic Dermatitis

Inclusion Criteria: 1. Male or female subjects aged ≥18≤75 years old. 2. Atopic dermatitis (AD) diagnosed at least half a year before screening. 3. Subject with EASI score ≥16, IGA ≥ 3, BSA ≥ 10% at screening and baseline. 4. Subjects with a history of an inadequate response or medically inappropriate use of topical drug treatment within 6 months Exclusion Criteria: 1. Received systemic corticosteroids, immunosuppressive/immunomodulatory drugs, phototherapy within the 4 weeks before randomization. 2. Received systemic traditional Chinese medicine treatment within the 4 weeks before randomization or topical traditional Chinese medicine treatment within 1 week before randomization 3. Received treatment with other clinical study drugs within 1 month or 5 half-lives before randomization (whichever is longer) 4. Received or planned to receive live vaccine treatment within the 3 months before randomization or during the study period. 5. Received allergen specific immunotherapy within the 3 months before randomization. 6. Have a history of allergies to any component of AK120 and/or severe allergic reactions to monoclonal antibodies.