BE BOLD phase IIIb: Bimekizumab vs risankizumab for active PsA

Updated results from the phase IIIb, head-to-head, multicenter, randomized, double-blind BE BOLD trial (NCT06624228), evaluating bimekizumab vs risankizumab in adults with active psoriatic arthritis (PsA), were presented by Joseph F. Merola at the European Alliance of Associations for Rheumatology (EULAR) 2026 Congress, June 3–6, 2026, London, UK. Patients were randomized 1:1 to bimekizumab (n = 277) or risankizumab (n = 276); eligible patients were biologic disease-modifying antirheumatic drug (bDMARD)-naïve or had inadequate response/intolerance to a maximum of one prior tumor necrosis factor inhibitor (TNFi), with tender joint count ≥3/68 and swollen joint count ≥3/66. The primary endpoint was American College of Rheumatology 50% response (ACR50) at Week 16. 

Key data: ACR50 at Week 16 was achieved by 49.1% with bimekizumab vs 38.0% with risankizumab (difference, 11.1%; p = 0.0058); Week 24 rates were 54.9% vs 43.8%, respectively. ACR50 was also higher with bimekizumab vs risankizumab at Week 4 (19.9% vs 7.2%; nominal p < 0.0001). Minimal disease activity (MDA) at Week 16 was numerically higher with bimekizumab (43.3% vs 39.9%; p = 0.3921), with Week 24 rates of 49.1% vs 42.4%. In patients with baseline body surface area (BSA) ≥3%, ACR50 + Psoriasis Area and Severity Index 100% response (PASI100) was numerically higher with bimekizumab vs risankizumab at Week 16 (33.5% vs 24.4%; nominal p = 0.0800). Disease Activity Index for Psoriatic Arthritis low disease activity + remission (DAPSA LDA + REM) was also numerically higher with bimekizumab through Week 24. Safety was comparable, with no new safety signals identified; Candida infections were more frequent with bimekizumab and were all mild/moderate.  

Key learning: BE BOLD provides the first head-to-head biologic evidence demonstrating the superiority of bimekizumab over risankizumab for a joint-focused endpoint in PsA. These findings may help guide clinical decision-making for the management of PsA.