Safety and effectiveness of dupilumab in the real‐world treatment of atopic dermatitis in Japan: 1‐year interim analysis from a post‐marketing surveillance

Abstract Objectives Atopic dermatitis (AD) is a common chronic inflammatory skin disorder in Japan. Dupilumab, a fully human monoclonal antibody, targets a shared subunit of the interleukin (IL)‐4 and IL‐13 receptors. Post‐marketing surveillance of the safety and effectiveness of dupilumab in adult AD patients was conducted in Japan, where the drug is also allowed for use in older adolescents (i.e., ≥15 years), and interim results are reported here. Methods This observational, multicenter study enrolled Japanese patients with AD who initiated dupilumab between July 2018–June 2020 (UMIN‐CTR Trials Registry: UMIN000032807). Baseline demographics, clinical history, medication data and dupilumab safety and effectiveness data were collected. Results By the data cut‐off date of March 26, 2021, information from 600 patients has been collected. All the available safety and 1‐year effectiveness data are presented. The mean (standard deviation) age was 42.0 (15.9) years, the majority (69.1%) were male, and asthma was present in 12.2%. Adverse drug reactions (ADRs) were observed in 98 patients (16.4%), including conjunctivitis (n = 40; 6.7%), conjunctivitis allergic (n = 30; 5.0%), blepharitis (n = 5; 0.8%), headache and eye pruritus (n = 4; 0.7% each) and eosinophilia (n = 3; 0.5%). Six patients experienced asthma, all of whom had a history of, or concurrent, asthma. Disease severity improved remarkably at 4 months in most patients, which was maintained up to 1 year. Conclusion Dupilumab appears to be a safe and effective treatment for patients aged ≥15 years with moderate‐to‐severe AD in routine clinical practice in Japan. Dupilumab was well tolerated, with no new safety signals and no new‐onset asthma.