Real-world effectiveness and safety of bimekizumab in Japanese patients with psoriasis: A single-center retrospective study.

Bimekizumab, which suppresses both interleukin (IL)-17A and IL-17F, has recently been approved as a biologic for psoriasis. We aimed to evaluate the real-world effectiveness and safety of bimekizumab for psoriasis and to identify predictive factors for its treatment responsiveness. We analyzed 36 Japanese patients with psoriasis (19 with psoriasis vulgaris and 17 with psoriatic arthritis) from May 2022 to September 2023. All patients received bimekizumab (320 mg every 4 weeks) until week 16. Seventeen patients (43.2%) had experienced bio-switch. The median (interquartile range) baseline total psoriasis area and severity index (PASI) was 6 (3.2-20.0). Total PASI rapidly and significantly decreased at week 4 by a median 79.8% from baseline, and gradually decreased thereafter. The PASI on the trunk, and upper and lower limbs rapidly and significantly decreased at week 4 compared to baseline and plateaued thereafter. The neutrophil-to-lymphocyte ratio and neutrophil number significantly decreased at week 16 compared to baseline. At weeks 4, 8, 12, and 16, the achievement rate of absolute PASI ≤2 was 72.2%, 80.6%, 92.9%, and 96.4%, respectively; that of absolute PASI ≤1 was 41.7%, 61.3%, 85.7%, and 82.1%; that of PASI 75 was 55.5%, 52.9%, 69.7%, and 75.8%; that of PASI 90 was 36.1%, 50.0%, 57.6%, and 62.9%; and that of PASI 100 was 19.4%, 38.2%, 51.5%, or 57.6%, respectively. Linear multivariate regression analysis revealed that younger age was associated with a higher percentage reduction of total PASI at weeks 4 and 8. There were no serious or fatal adverse events during treatment. In conclusion, bimekizumab rapidly and remarkably reduced the total PASI together with high achievement rates of absolute PASI ≤1 and ≤2, and with favorable safety in real-world clinical practice. Younger age may be a predictive factor for a good treatment response to bimekizumab.