Bimekizumab efficacy and safety through 3 years in patients with moderate to severe plaque psoriasis: Long-term results from the BE RADIANT phase 3b trial open-label extension period

Abstract Background Overexpression of interleukin (IL)-17A and IL-17F significantly influences psoriasis pathology. Until recently, biologics targeting IL-17A alone, like secukinumab, were used to treat psoriasis. Bimekizumab is a monoclonal IgG1 antibody that targets both IL-17A and IL-17F. BE RADIANT was the first phase 3 study to investigate switching from selective inhibition of IL-17A to dual inhibition of IL-17A and IL-17F. Bimekizumab has previously shown superior achievement of complete skin clearance (PASI 100) versus secukinumab through 48 weeks. Switching from secukinumab to bimekizumab resulted in improved clinical responses. Over 2 years, no new safety signals were observed. Objective To report 3-year efficacy and safety of bimekizumab in patients with moderate to severe plaque psoriasis receiving continuous bimekizumab, or switching from secukinumab after 1 year. Methods The BE RADIANT phase 3b randomised controlled trial had a 48-week double-blinded period, in which patients received bimekizumab (320 mg every 4 weeks [Q4W]), or secukinumab (300 mg weekly to Week 4, then Q4W). At Week 16, bimekizumab-randomised patients underwent re-randomisation to receive Q4W or Q8W maintenance dosing. From Week 48 onwards (open-label extension), all received bimekizumab. Results 336 bimekizumab- and 318 baseline secukinumab-randomised patients entered the open-label extension. Among these, more bimekizumab-randomised patients achieved PASI 100 (modified non-responder imputation) at Year 1 (74.9%) versus secukinumab-randomised patients (52.8%). PASI 100 response rates were maintained over 3 years in bimekizumab-treated patients (68.8%) and increased in secukinumab-randomised patients switching to bimekizumab (68.8%). Bimekizumab was well-tolerated to 3 years. In patients receiving ≥1 bimekizumab dose, the most common treatment-emergent adverse events (TEAEs) over 3 years were nasopharyngitis, oral candidiasis, and upper respiratory tract infection (exposure adjusted incidence rates: 12.2, 10.0, and 5.5/100 patient-years, respectively). Rates of TEAEs of interest, including serious infections, inflammatory bowel disease, and suicidal ideation and behaviour, did not increase with longer exposure to bimekizumab from 1 to 3 years. Conclusion Over two-thirds of bimekizumab-randomised patients and those switching from secukinumab to bimekizumab achieved and maintained complete skin clearance over 3 years of treatment. Over 3 years, bimekizumab was well-tolerated, and TEAE rates did not increase with longer exposure.