Real‐world safety and effectiveness of adalimumab in patients with hidradenitis suppurativa: 12‐week interim analysis of post‐marketing surveillance in Japan

Hidradenitis suppurativa (HS) is a painful chronic skin disease characterized by abscesses, nodules, and tunnels in the skin. Adalimumab, a monoclonal antibody against tumor necrosis factor‐α, is approved for the treatment of HS in Europe, the USA, and Japan. This multicenter, open‐label, post‐marketing, observational study (ClinicalTrials.gov: NCT03894956) evaluated the safety and effectiveness of adalimumab in routine clinical practice in Japan (March 2019–May 2021). Patients with HS were treated with s.c. doses of adalimumab according to the dosage described in the package insert. The primary end‐point was safety (data cut‐off, December 2020). Secondary end‐points assessed effectiveness, including HS Clinical Response (HiSCR), skin pain, Dermatology Life Quality Index (DLQI), and C‐reactive protein (CRP). Here, we report 12‐week interim effectiveness results. A total of 84 eligible patients from 65 sites were enrolled; 83 patients were included in this analysis. Mean age was 42.0 years, mean body mass index was 26.9 kg/m(2), 78.3% of patients were male, 61.4% had Hurley stage III disease, 39.8% had a disease duration ≥10 years, and 7.2% had a family history of HS. The most common affected sites were the axilla (60.2%), buttocks (59.0%), and the inguinal and femoral regions (47.0%). Mean abscess and inflammatory nodule count was 13.0 (standard deviation, 12.0). Among patients with a comorbidity (57.8%), the most common were diabetes mellitus, hypertension, and chronic kidney disease. No patient reported a serious infection or any safety event of special interest. One patient died from a serious adverse event of cardiac failure unrelated to adalimumab. At week 12, 57.4% of patients achieved HiSCR, and significant reductions from baseline in skin pain, DLQI (both p < 0.0001), and CRP (p = 0.0029) were observed. These results support the administration of adalimumab as a well‐tolerated and effective treatment for Japanese patients with HS in real‐world clinical practice.