Real-World Effectiveness and Safety of Bimekizumab for Moderate-to-Severe Hidradenitis Suppurativa: A Multicenter Retrospective Study from the Italian Landscape HS (IL-HS)

INTRODUCTION: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by painful nodules, abscesses, draining tunnels and substantial impairment in quality of life. Bimekizumab, a monoclonal antibody that selectively inhibits interleukin-17A and interleukin-17F, was recently approved in Italy for the treatment of moderate-to-severe HS. However, real-world evidence remains limited. METHODS: This was a retrospective multicenter study of patients with HS treated with bimekizumab across Italian dermatology referral centers. Effectiveness was assessed at weeks 4, 16 and 24 using the following measurement tools and scales: Hidradenitis Suppurativa Clinical Response (HiSCR), HiSCR75, HiSCR90, HiSCR100 (at least 75%, 90% and 100% reductions in AN count, respectively, plus HiSCR criteria), the International Hidradenitis Suppurativa Severity Score System 55% reduction (IHS4-55), International Hidradenitis Suppurativa Severity Score System (IHS4), draining tunnel count, abscess and inflammatory nodule (AN) count, AN50 (at least 50% reduction in AN), pain numerical rating scale (NRS-pain), NRS50 (as at least a 50% reduction in NRS-pain compared with baseline) and Dermatology Life Quality Index (DLQI). Safety outcomes included adverse events, rescue therapies and concomitant treatments. RESULTS: , 75% had Hurley stage III disease and 80% had prior biologic exposure. HiSCR was achieved by 36 of 100 (36.0%) patients at week 4, 60 of 100 (60.0%) patients at week 16 and 41 of 53 (77.4%) patients at week 24. HiSCR75 was achieved by 24 of 100 (24.0%) patients, 48 of 100 (48.0%) patients and 35 of 53 (66.0%) patients at weeks 4, 16 and 24, respectively. Median IHS4 decreased from 18 at baseline to 7 at week 24; median draining tunnel count decreased significantly from baseline at all visits, median AN count decreased from 3.5 to 1, median NRS-pain decreased from 8 to 3, and median DLQI decreased from 19.5 to 7. IHS4-55 was achieved by 54.7% of evaluable patients at week 24. Flare rates remained below 10% throughout follow-up. Any adverse event was reported in 22 patients (22.0%). CONCLUSION: In this multicenter Italian real-world cohort, bimekizumab was associated with early clinical improvement and meaningful reductions in disease activity, pain and quality-of-life burden; week-24 estimates should be interpreted in light of administrative censoring.