Bimekizumab Versus Secukinumab Continuous Maintenance of PASI 90 and PASI 100 Responses through One Year in Patients with Moderate to Severe Plaque Psoriasis: Post-HOC Results from the BE RADIANT Phase 3b Trial

Introduction: Bimekizumab (BKZ) is a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F in addition to IL‑17A.[1] Secukinumab (SEC) is a widely used monoclonal IgG1 antibody that targets IL-17A. BE RADIANT was the first phase 3 study to compare inhibition of IL-17A and IL-17F with inhibition of IL-17A alone. Patient (pt) surveys have confirmed that maintaining a long-lasting response is a key treatment goal for patients who have already achieved skin clearance.[2,3] Here, we assess the efficacy of BKZ vs SEC in continuously maintaining an improvement of ≥90% in the Psoriasis Area and Severity Index (PASI 90), and PASI 100 responses, at every visit from Week (Wk)16 to Wk48 of treatment in pts with moderate to severe plaque psoriasis. Procedure/study: BE RADIANT was a phase 3b, randomized trial, consisting of a 48-week double-blinded, active comparator-controlled period followed by an open-label extension.[4] Pts were randomized 1:1 to BKZ 320 mg every 4 wks (Q4W) or SEC (weekly to Wk4 then Q4W). At Wk16, BKZ-randomized pts either continued to receive BKZ 320 mg Q4W or switched to BKZ 320 mg every 8 wks (Q8W). This analysis includes pts who achieved PASI 90 or 100 at Wk16 and continued to receive study medication at Wk16 or later, reported with BKZ dose groups pooled. We report the proportion of responders who continued to achieve their response at every study visit up to and including Wk48. Missing data were imputed as non-response. Results: At baseline, 373 pts were randomized to BKZ, and 370 were randomized to SEC. At Wk16, 319/373 (85.5%) BKZ-randomized and 273/370 (73.8%) SEC-randomized pts achieved PASI 90; 230/373 (61.7%) and 180/370 (48.6%) achieved PASI 100. PASI 90 was continuously maintained at each study visit from Wk16–Wk48 by 242/319 (75.9%) BKZ-treated and 177/273 (64.8%) SEC-treated Wk16 responders. PASI 100 was continuously maintained through Wk48 by 139/230 (60.4%) BKZ-treated and 93/180 (51.7%) SEC-treated Wk16 responders. Conclusion: A higher proportion of pts treated with BKZ continuously maintained their Wk16 PASI 90 and PASI 100 responses at every visit during the first treatment year compared to SEC. Funding: UCB Pharma. Medical writing support: Costello Medical.