Efficacy and Predictors of Low-Dose Abrocitinib in Chinese Adults with Moderate-to-Severe Atopic Dermatitis: A Prospective Study.

Background: Real-world data on abrocitinib 100 mg for moderate-to-severe atopic dermatitis (AD) in Asians remain limited. This study evaluates effectiveness, regional responses, safety, and predictors of low-dose abrocitinib in Chinese adults. Methods: A single-center prospective study (n = 40) in adults with moderate-to-severe atopic dermatitis received abrocitinib 100 mg once daily. Assessments occurred at baseline, Weeks 2, 4, 12, and 24. Primary endpoints: Week 12 Eczema Area and Severity Index 75% improvement (EASI-75) and safety. Secondary: region-specific Eczema Area and Severity Index improvement, patient-reported outcomes, and predictive factor analysis. Univariate logistic regression was used to identify predictors of response; multivariable analyses were exploratory due to limited sample size. Results: At Week 12, 60.0% achieved EASI-75, 42.5% EASI-90, and 42.5% Investigator Global Assessment response. Significant improvements occurred in EASI (-90.8%), pruritus, and quality-of-life. By Week 24 (subgroup), EASI-75 and EASI-90 rates rose to 90.9% and 68.2%, respectively. Regional EASI reduction exceeded 90% in head/neck, trunk, and upper limbs. Baseline immunoglobulin E (IgE) ≥100 IU/mL predicted a lower Week 2 response (OR = 0.20; P = 0.030), while age ≥45 years showed a non-significant trend toward better Week 4 response. Safety analysis included all 40 patients through Week 12 and 22 patients through Week 24, with 13 treatment-emergent adverse events reported, predominantly mild to moderate respiratory and gastrointestinal events. No major adverse cardiovascular events were observed during follow-up. Conclusion: Low-dose abrocitinib 100 mg once daily is effective and well tolerated, providing rapid and regionally consistent disease control in Chinese adults with moderate-to-severe AD. Baseline IgE may predict early response, supporting personalized management. These findings support low-dose abrocitinib as a viable therapy and highlight its potential role in personalized atopic dermatitis management.