Real-Life Effectiveness and Safety of Bimekizumab in Plaque Psoriasis Involving Difficult-to-Treat Areas: A 52-Week, Retrospective Real-World, Single-Center Study

<b>Background:</b> Psoriasis is a chronic inflammatory disease that frequently affects difficult-to-treat areas such as the scalp, nails, genitalia, and palms/soles, with significant physical and psychological burden. Bimekizumab, a monoclonal antibody targeting both interleukin (IL)-17A and IL-17F, has shown rapid and durable efficacy in clinical trials, but real-world data in these subgroups remain limited. <b>Methods</b>: We performed a 52-week, single-center retrospective study including patients with psoriasis involving at least one difficult-to-treat area. Effectiveness was assessed using site-specific Physician's Global Assessment (sc-PGA, f-PGA, sPGA-G, pp-PGA). The primary endpoint was the proportion of patients achieving a PGA 0/1 (clear or almost clear). Safety data were collected at each visit. <b>Results:</b> Eighty-five patients were included (61.8% male; mean age 48.1 years; mean Body Mass Index (BMI, 26.9 kg/m²). Difficult-to-treat areas involved were the scalp (70.6%), nails (41.2%), genitalia (27.1%), and palms/soles (24.7%). At week 52, sc-PGA 0/1 was achieved in 90.6% of patients, sPGA-G 0/1 in 81.3%, f-PGA 0/1 in 66.7%, and pp-PGA 0/1 in 87.5%. Mean PGA values progressively decreased across all sites. The most common adverse event was oral candidiasis (11.8%). <b>Conclusions:</b> Bimekizumab showed rapid, sustained, and clinically meaningful improvement across all difficult-to-treat areas with a favorable safety profile.