Long-Term Outcomes of Secukinumab in Moderate-to-Severe Hidradenitis Suppurativa: A Multicentre Cohort Study

Background: Hidradenitis suppurativa (HS) is a chronic and debilitating skin disorder. Secukinumab, a biologic agent targeting interleukin-17, is a new therapeutic option for HS. However, data regarding its long-term outcomes are scarce. Objective: To evaluate the long-term effectiveness, safety, and predictors of response to secukinumab in a real-world cohort of patients with moderate-to-severe HS. Methods: Multicentre retrospective cohort study across 12 Italian tertiary referral hospitals. The primary effectiveness outcomes were the proportion of patients achieving Hidradenitis Suppurativa Clinical Response (HiSCR) and a 55% reduction in the International Hidradenitis Suppurativa Severity Score System (IHS4-55) at any time point. Results: A total of 77 patients (53% female; median age 38 years, interquartile range: 27-50) met the inclusion criteria. At week 52, 36.2% of patients achieved HiSCR and 55.6% achieved IHS4-55. The mean reduction from baseline to week 52 was 50.8% for skin pain Numeric Rating Scale and 55.2% for Dermatology Life Quality Index. Agreement between IHS4-55 and HiSCR was 76.6% (Cohen's kappa 0.5255; 95% CI: 0.4307-0.6202, P < .0001). Patients in Hurley stage 3 had a significantly lower hazard ratio (HR) of achieving IHS4-55 than those in Hurley stage 2 (HR 0.52; 95% CI: 0.31-0.89, P = .017), which persisted in the multivariable model (HR 0.56; 95% CI: 0.31-0.99, P = .044). No new safety concerns were identified. Conclusions: This study suggests that secukinumab provides clinically meaningful long-term outcomes in HS management, even in bio-experienced patients.