Gender Influence on Bimekizumab Response in Patients with Psoriasis: Results of a Real-World Multicenter Retrospective Study-IL PSO (Italian Landscape PSOriasis)

Introduction: Several studies have demonstrated that psoriasis severity is generally greater in male patients, but it is unclear whether this gender difference may affect short-term therapeutic response. Notably, no studies have specifically investigated bimekizumab, a humanized, full-length IgG1 monoclonal antibody that acts as a dual inhibitor of interleukin (IL)-17A and IL-17F. Methods: This was a cross-sectional, observational, retrospective, multicenter analysis. A cohort of 318 patients with moderate to severe psoriasis, 229 male patients (median [IQR] age 35 [23-67] years) and 89 female patients (median [IQR] age 33 [20-68] years), were retrospectively evaluated for short-term response (16 weeks) to bimekizumab according to standard dosage (320 mg at weeks 0, 4, 8, 12, and 16, and every 8 weeks thereafter). Patients were assessed to evaluate whether gender differences in demographic and clinical characteristics can affect treatment response to standard dose of bimekizumab, during the first 16 weeks of treatment. Therapeutic outcomes were evaluated by analyzing Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) scores recorded in each patient at three consecutive time points: baseline (T0), after 4 weeks (T4), and after 16 weeks of treatment (T16). Results: Male patients showed more severe disease at baseline, compared to female patients (p = 0.01). A significant reduction in disease severity was observed in both male and female patients after 16 weeks of treatment, but male patients showed a faster decrease in PASI score between baseline and week 4 of treatment compared to female patients (p < 0.001). Nevertheless, by week 16, difference in PASI response and DLQI reduction between genders became less pronounced. Conclusion: Although male patients exhibit greater disease severity at baseline compared to female patients, this does not result in a differential response to bimekizumab over the short term. Both male and female patients had equal probability of achieving complete or near-complete disease remission within the first 4 weeks of treatment, and both maintain this response status through week 16. The therapeutic benefit of bimekizumab may be due to the rapid dual inhibition of IL-17A and IL-17F, which may lead to consistent and robust clinical response across genders, regardless of baseline disease severity. Our results suggest a "gender severity-invariant effect" of bimekizumab, highlighting the treatment as rapidly effective in both genders, despite initial differences in disease severity.