A Study to Evaluate the Efficacy and Safety 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 who are suitable for continue using biological treatment assessed byinvestigator

Exclusion Criteria:

1. Acute onset of AD within 4 weeks before drug administration.

2. The accompany disease have been assessed by the investigators during screeningperiod as unsuitable for participation in this study.

3. Any history or symptoms of malignant tumors in any organ within 5 years prior toscreening, regardless of whether treatment has been received and whether there aresigns of recurrence or metastasis

4. Have a known or suspected history of immunosuppressive diseases, including a historyof invasive infections.

5. Having undergone or planned major surgery within 4 weeks prior to drugadministration, or unable to fully recover from surgery prior to drugadministration.

6. any medical or psychological condition that puts subjects at risk or may affect thestudy results assessed by investigators.