Real‐world safety and effectiveness of adalimumab in patients with pyoderma gangrenosum: Interim analysis of a post‐marketing observational study in Japan

Pyoderma gangrenosum (PG) is a rapidly progressive disease characterized by deep ulcers, predominantly in the lower extremities. Adalimumab, a monoclonal antibody against tumor necrosis factor alpha, is the first drug approved for PG treatment in Japan, ahead of other countries. We conducted a multicenter, open-label, post-marketing observational study to evaluate the safety and effectiveness of adalimumab in Japanese patients with PG. Of 67 patients enrolled, 37 in the safety analysis set and 32 in the effectiveness analysis set were included in this interim analysis. (Nineteen patients whose case report forms were not collected and 11 whose data were not fixed by the data cut-off date were excluded from the study). In the safety analysis set, the mean age was 62.9 years and 86.5% of patients had comorbidities, including ulcerative colitis (21.6%), diabetes mellitus (18.9%), and hypertension (10.8%); subtypes of PG included ulcerative (n = 33), vegetative (n = 2), and pustular (n = 2). Mean exposure duration to adalimumab was 185.5 days. Systemic steroids were used before (70.3%) and during (56.8%) adalimumab treatment. The incidence proportion of overall adverse drug reactions was 18.9%. The incidence proportions of all infections and serious infections reported as adverse drug reactions were 13.5% and 10.8%, respectively. The proportion of patients with a Physician Global Assessment score (total lesions) of 0/1 at weeks 12, 26, and 52 was 42.9%, 36.8%, and 50.0%, respectively. This interim analysis revealed the characteristics of Japanese patients with PG treated with adalimumab in the actual clinical setting and the real-world safety and effectiveness of adalimumab. At the time of the interim analysis, adalimumab treatment was generally well tolerated, and no new safety concerns were detected. Further follow-up of this study will provide a more detailed understanding of the long-term safety and effectiveness of adalimumab in patients with PG refractory to conventional treatments.