This is a multi-center, randomized, double blind, placebo-controlled phase IIb study to evaluate the efficacy, safety, PK, PD and immunogenicity of CM310 in moderate-severe AD subjects. The study consists of 3 periods, a up-to-4-week Screening Period, a 16-week randomized Treatment Period and a 8-week Safety Follow-up Period.

Subjects will be required to apply moisturizers after ICF signed and continue throughout the study.

Inclusion Criteria:

• Diagnosed as AD for at least 12 months before Screening, with below requirements: 1)EASI score ≥16 at Screening and Baseline; 2) IGA score ≥3 (0-5 points scale) at Screening and Baseline; 3) ≥10% BSA of AD involvement at Screening and Baseline; 4) Pruritus NRS average score ≥3 at Baseline.
• Inadequate response to topical medications.

Exclusion Criteria:

• Not enough washing-out period for previous therapy.
• Concurrent disease/status which may potentially affect the efficacy/safety judgement.
• Organ dysfunction.
• pregnancy.
• Other.