XKH-001

Main objectives: 1. To evaluate the safety of XKH001 in adult patients with moderate to severe AD; 2. To evaluate the efficacy of XKH001 in adult patients with moderate to severe AD at week 16. Secondary objectives: 1. To evaluate the efficacy of XKH001 on clinical symptoms, signs and quality of life in adult patients with moderate to severe AD at week 16 and other visit points (quality of life is only evaluated in the second phase of this trial); 2. To evaluate the pharmacokinetic (PK) characteristics of XKH001 in adult patients with moderate to severe AD; 3. To evaluate the pharmacodynamic (PD) characteristics of XKH001 in adult patients with moderate to severe AD; 4. To evaluate the immunogenicity of XKH001 in adult patients with moderate to severe AD; 5. To analyze the relationship between drug exposure and clinical efficacy (E-R) of XKH001 in adult patients with moderate to severe AD (analyzed only in the second phase of this trial). Exploratory objectives: 1. To explore the relationship between biomarkers in skin tissue of adult patients with moderate to severe AD and the efficacy of XKH001.