UCB reported positive Week 16 results from the Phase 3 BE BOLD trial, with BIMZELX (bimekizumab) demonstrating statistically significant superiority over SKYRIZI (risankizumab) in achieving ACR50 responses in adults with active psoriatic arthritis.
Written By: Farha Farheen, PharmD
Reviewed By: Pharmacally Editorial Team
UCB has announced positive Week 16 results from the Phase 3 BE BOLD trial (NCT06624228), showing that BIMZELX achieved superior joint response outcomes compared with SKYRIZI in adults with active psoriatic arthritis (PsA). Findings will be presented at the EULAR Annual Meeting 2026 in London, June 3–6.
The study met its primary endpoint, with 49.1% of patients treated with bimekizumab achieving an ACR50 response at Week 16 compared with 38.4% of patients receiving risankizumab (p=0.0078). ACR50 is a stringent efficacy measure requiring at least a 50% improvement in joint symptoms and disease activity.
Professor Iain McInnes, University of Glasgow, College of Medical Veterinary and Life Sciences, Glasgow, UK said the findings demonstrate clinically meaningful improvements in joint disease control and could help clinicians make earlier treatment decisions for patients with PsA.
Emmanuel Caeymaex, executive vice president and head of patient evidence at UCB, said the head-to-head results add important comparative evidence supporting bimekizumab in psoriatic disease treatment.
According to UCB, bimekizumab is the first approved biologic to demonstrate statistically significant superiority in ACR50 outcomes in a direct head-to-head PsA trial. The company also noted that BE BOLD is the first PsA head-to-head study to include an IL-23 inhibitor comparator.
Secondary endpoints showed numerically higher minimal disease activity (MDA) rates at Week 16 with bimekizumab (43.0%) compared with risankizumab (39.9%), although the difference did not meet statistical significance under the trial’s hierarchical testing strategy. As a result, subsequent secondary endpoint analyses were considered descriptive.
In a subgroup of patients with psoriasis affecting at least 3% body surface area at baseline, simultaneous ACR50 and PASI100 responses, indicating complete skin clearance, were achieved by 33.5% of patients treated with bimekizumab compared with 24.4% of those receiving risankizumab. Exploratory analyses also showed higher rates of low disease activity or remission based on DAPSA scoring with bimekizumab treatment.
Earlier ACR50 responses were observed with bimekizumab, with 19.9% of patients achieving ACR50 at Week 4 compared with 7.2% in the risankizumab arm.
Safety profiles were generally comparable between treatment groups. Treatment-emergent adverse events occurred in 57.0% of patients treated with bimekizumab and 52.0% of those treated with risankizumab. Candida infections were more frequent with bimekizumab, although all reported cases were mild or moderate and none resulted in treatment discontinuation. Serious adverse event rates remained low across both groups.
Psoriatic arthritis is a chronic inflammatory disease affecting joints and skin that develops in approximately 30% of people with psoriasis and can lead to progressive structural joint damage if left uncontrolled.
The BE BOLD trial (NCT06624228) enrolled 553 adults with active PsA, including biologic-naïve patients and individuals previously exposed to one tumor necrosis factor inhibitor (TNFi). Participants were randomized to receive either bimekizumab or risankizumab in a double-blind study design using protocol-defined dosing schedules based partly on baseline psoriasis severity.
Earlier this year, UCB also reported long-term data showing durable psoriasis remission with BIMZELX and sustained three-year disease control in hidradenitis suppurativa from the Phase 3 BE HEARD program.
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About the Writer
Farha Farheen, PharmD (LinkedIn) is a pharmacy professional with a strong interest in pharmacovigilance and clinical research. She has completed her Doctor of Pharmacy (Pharm.D) along with her internship as a Clinical Pharmacist. She has hands-on experience in adverse drug reaction (ADR) reporting, safety data documentation, and pharmacovigilance workflows, and is proficient in using VigiFlow. She is also a patent holder for an antibacterial formulation enriched with bioactive substances, granted by the German Patent and Trademark Office.