This is a multicenter, randomized, open label phase II clinical study to evaluate the safety and efficacy of AK120 in the treatment of subjects with moderate to severe atopic dermatitis.

This is a multicenter, randomized, open label phase II clinical study to evaluate the safety and efficacy of AK120 in the treatment of subjects with moderate to severe atopic dermatitis. The total duration of the study (including screening period) planned for each subject is approximately 29 weeks.

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.