A Study of SHR-1819 in Patients With Moderate-to-severe Atopic Dermatitis

Inclusion Criteria: 1. At the time of signing the informed consent, the subjects are ≥18 years old and ≤75 years old, male or female. 2. The subjects have voluntarily signed the informed consent form prior to the start of any procedures related to the study, are able to communicate smoothly with the researcher, understand and are willing to strictly abide by the requirements of this clinical research protocol to complete the study. 3. Topical emollients are applied at a stable dose twice daily for at least 7 days before the first dose in the run-in phase and continued for the duration of the study. 4. Have atopic dermatitis at the time of screening and have an investigator-assessed history of atopic dermatitis for at least 1 year before screening. 5. Have moderate to severe atopic dermatitis during the screening period and on the day of the first dose. Exclusion Criteria: 1. Have other active skin disease or skin complications due to other conditions that may affect the evaluation of Atopic Dermatitis (AD). 2. A history of spring keratoconjunctivitis and/or atopic keratoconjunctivitis within 6 months prior to screening. 3. Has malignancy or has a history of malignancy. 4. Have serious concomitant diseases and other conditions that the investigator considers inappropriate to participate in this trial. 5. Hypersensitivity to the study drug or any ingredient in the study drug. 6. Females who are pregnant or lactating.