Evaluation of Dupilumab in Patients With Bullous Pemphigoid

Importance: Dupilumab is a theoretically novel therapy for bullous pemphigoid (BP). However, its effectiveness and safety have yet to be confirmed in a large-scale study. Objective: To assess the efficacy and safety of dupilumab in patients with BP and evaluate factors that potentially affect short-term and long-term outcomes. Design, Setting, and Participants: A retrospective cohort study was conducted from January 1, 2021, to July 31, 2022. The median (IQR) follow-up period was 24.6 (11.5-38.4) weeks. This multicenter study was performed in 6 dermatology departments of the National Autoimmune Bullous Diseases Cooperative Group of China. Adult patients with BP that received 300 mg of dupilumab every 2 weeks following an initial dose of 600 mg were included. Patients were eligible if they had a clinical presentation of BP combined with immunological or pathological evidence. Patients with drug-induced BP, with less than 4 weeks of follow-up, and who received dupilumab or any other biologics within 6 months were excluded. Main Outcomes and Measures: The primary outcome was the proportion of patients who achieved disease control within 4 weeks. Disease control was defined as the absence of new lesions and pruritus, combined with the healing of existing lesions. Complete remission rates, relapse rates, changes in Bullous Pemphigoid Disease Area Index (BPDAI) scores, itching numerical rating scale (NRS) scores, laboratory results within 64 weeks, and adverse events (AEs) were also assessed. Results: Among 146 patients (median [IQR] age, 73 [64-85] years; 86 [58.9%] male patients) included in the study, 127 (87.0%) patients achieved disease control within 4 weeks, with a median (IQR) time of 14 (7-14) days. A total of 52 (35.6%) patients achieved complete remission, and 13 (8.9%) patients relapsed during the observation period. The complete remission rate and cumulative relapse rate at week 64 were 62.5% (5 of 8) and 30.9%, respectively. There was rapid and sustained improvement in clinical indicators and laboratory examination results after dupilumab treatment, including BPDAI scores, itching NRS scores, serum anti-BP180 and anti-BP230 antibodies, total IgE levels, and eosinophil count. Of these 146 patients, 107 (73.3%) did not report any AEs. The most common AEs were infections and eosinophilia. Serum anti-BP180 antibody levels of greater than 50 relative units (RU)/mL (OR, 3.63; 95% CI, 0.97-12.61; P = .045) were associated with 4-week disease control, and male patients were more likely to relapse (HR, 10.97; 95% CI, 1.42-84.92; P = .02). Conclusions and Relevance: In this retrospective cohort study, dupilumab treatment was associated with improved clinical symptoms in patients with BP. The safety profile was favorable, although concurrent infection and eosinophilia might pose potential concerns. This study suggests that patients with anti-BP180 antibody levels of at least 50 RU/mL and female sex may respond better.