UCB has announced new week 16 results from the phase 3 BE BOLD trial showing that bimekizumab delivered superior joint outcomes to risankizumab in adults with active psoriatic arthritis.
The data, presented at the 2026 EULAR Annual Meeting in London, mark the first time an approved biologic has demonstrated statistically significant superiority in joint outcomes in a head‑to‑head psoriatic arthritis study.
The primary endpoint was met, with 49.1% of patients receiving bimekizumab achieving ACR50 at week 16 compared with 38.4% receiving risankizumab.
Improvements were also seen across secondary endpoints, although these did not reach statistical significance within the prespecified testing hierarchy. Numerically higher responses were observed for bimekizumab across all secondary measures.
Professor Iain McInnes, University of Glasgow, said: “Delivering high-level clinical responses is crucial for people with psoriatic arthritis. Achieving ACR50 level responses in clinical trials indicates joint improvements that correlate closely with clinically meaningful reductions in disease activity, inflammation control and consequent improvements in quality of life.
“The new BE BOLD data, showing bimekizumab achieved superiority vs risankizumab in ACR50 at Week 16 in a direct head-to-head trial design, can support clinicians in making early informed decisions for treating this chronic inflammatory disease.”
Emmanuel Caeymaex, Executive Vice President at UCB, said: “We are proud to announce results demonstrating the superiority of bimekizumab over risankizumab in improving joint outcomes, providing significant evidence that can inform the treatment landscape for psoriatic arthritis.
“Head-to-head trials are the most rigorous approach to comparative clinical research. BE BOLD reflects UCB’s commitment to scientific excellence through generating high-quality evidence, that supports advancing care for people living with psoriatic disease.”
Early joint improvements were seen as soon as week 4, with 19.9% of patients on bimekizumab achieving ACR50 compared with 7.2% on risankizumab. Complete skin clearance (PASI100) at week 16 was achieved by 53.4% of those receiving bimekizumab and 46.6% receiving risankizumab.
No new safety signals were identified. Candida infections were more frequent with bimekizumab but were mild or moderate, and no cases led to discontinuation. Rates of treatment‑emergent adverse events were comparable between treatment arms, with low and identical discontinuation rates.
