Efficacy and Safety of Switching to Ivarmacitinib in Patients With Moderate-to-Severe Atopic Dermatitis With Inadequate Response to Interleukin-4 Receptor Alpha(IL-4Rα) Inhibitors: A Prospective, Multicenter, Real-World Study

Inclusion Criteria: * Aged between 18 and 75 years. * Patients diagnosed with moderate-to-severe atopic dermatitis and treated with IL-4Rα inhibitors according to standard regimens for a minimum of 12 weeks. * Meeting any of the following disease activity criteria: EASI ≥16, WI-NRS ≥4. Exclusion Criteria: * Treatment with other JAK inhibitors, including topical formulations, within one week before enrollment. * Subjects with clinically significant diseases of the heart, liver, kidney, or other major organ systems. * Subject has any of the following abnormalities in clinical laboratory tests at screening, as assessed by the study-specific laboratory and confirmed by a single repeat, if deemed necessary: a. Absolute lymphocyte count of \<0.50 x 10\^9 /L (\<500/mm3);b. Absolute Neutrophil Count (ANC) of \<1 X 10\^9/L (\<1000/mm3);c. Hemoglobin level \< 80 g/L. * Subject with a prior history of thromboembolic events, including deep vein thromboses (DVT), pulmonary embolism, cerebrovascular accidents and those with known inherited conditions that predispose to hypercoagulability. * Presence of an active severe acute or chronic bacterial, fungal, or viral infection requiring systemic therapy. * Subjects with active tuberculosis or known active hepatitis B and/or hepatitis C infection. * Subject has any malignancies or has a history of malignancies with the exception of adequately treated or excised non-metastatic basal cell or squamous cell cancer of the skin, or cervical car…