Introduction: Abrocitinib, a selective Janus kinase (JAK)-1 inhibitor, is approved for the treatment of moderate-to-severe atopic dermatitis (AD). Although several real-world studies evaluated the safety and efficacy of abrocitinib, most have been limited by small sample sizes, and there are limited data on South Korean patients with AD. In addition, real-world comparative data across oral JAK inhibitors for AD remain limited.
Methods: We conducted a retrospective, single-center cohort study at the National Medical Center in Seoul, Korea. Patients aged ≥ 12 years with moderate-to-severe AD (baseline EASI ≥ 7) who initiated abrocitinib between September 2022 and April 2024 were included in the primary cohort; additional cohorts treated with upadacitinib or baricitinib during predefined periods were analyzed for between-drug comparisons. Efficacy was assessed at baseline, week 2, and week 16 using the Eczema Area and Severity Index (EASI) and patient-reported outcomes (PROs). Safety was evaluated by adverse events (AEs), physical examinations, and laboratory tests.
Results: Of the 66 patients enrolled, 57 patients completed 16 weeks of abrocitinib treatment in the analysis. The mean EASI score significantly decreased after 16 weeks. At week 16, 94.4%, 72.2%, and 25.9% of patients with AD achieved EASI-50, -75, and -90, respectively. Additionally, of the 21 patients who had previously experienced biologics or other JAK inhibitors, 95.5%, 72.7%, and 22.7% achieved EASI-50, -75, and -90, respectively. Further analysis of the EASI breakdown showed improvements of more than 80% across all body regions, with the lower extremities showing the greatest reduction (87.5%) and lichenification exhibiting the highest symptom improvement (89.7%). In descriptive, unadjusted comparisons, abrocitinib showed numerically higher EASI-50 and EASI-75 response rates at week 16 than upadacitinib and baricitinib. Acne was the most frequent adverse event with abrocitinib (43.9%), followed by urticaria (24.6%) and herpes simplex infection (12.3%); no dose reductions or treatment discontinuations due to adverse events occurred.
Conclusion: Abrocitinib demonstrates real-world efficacy and safety in moderate-to-severe AD, including patients with inadequate responses to other dupilumab or JAK inhibitors, including those with prior exposure to biologics or other JAK inhibitors.
Keywords: Abrocitinib; Atopic dermatitis; JAK inhibitor; Real-world data.
Abrocitinib is an oral medicine approved for adults and adolescents with moderate-to-severe atopic dermatitis (AD). It is taken once daily (100 mg or 200 mg) and works by blocking a signaling pathway in the immune system called Janus kinase (JAK). Real-world evidence in South Korea and comparisons with other oral JAK inhibitors (upadacitinib and baricitinib) are limited. In this retrospective study, we reviewed the medical records of 66 Korean patients with moderate-to-severe AD who started abrocitinib at a single center, along with additional patients treated with upadacitinib or baricitinib during predefined periods at the same center. We assessed changes in disease severity scores and patient-reported symptoms over 16 weeks and recorded side effects and laboratory findings. Most patients receiving abrocitinib showed rapid improvement within 2 weeks, and these benefits were maintained through week 16, including in patients who previously had an inadequate response to dupilumab or another JAK inhibitor. The most common side effect was acne, followed by urticaria and herpes simplex infection, and no patients discontinued abrocitinib because of adverse events. These findings suggest that abrocitinib is an effective and generally well-tolerated treatment option for Korean patients with moderate-to-severe AD in routine clinical practice.
© 2026. The Author(s).