BE BOLD Efficacy and Safety Data: Comparing Bimekizumab and Risankizumab on Joint-Centric Endpoints

In this installment of the Managed Healthcare Executive Between the Lines series, Philip Mease, MD, of Swedish Medical Center, Providence St. Joseph Health, and the University of Washington, walks through the actual 16-week efficacy and safety results from the BE BOLD head-to-head trial of bimekizumab versus risankizumab in active psoriatic arthritis.

Dr. Mease starts with the primary endpoint, ACR50 response at week 16, achieved by 49.1% of bimekizumab-treated patients compared with 38.4% on risankizumab, a statistically significant difference (p=.0078). Moving down the multiplicity-controlled hierarchy, minimal disease activity favored bimekizumab numerically (43% vs. 39.9%) but did not reach statistical significance, which Dr. Mease attributes to the high combined skin, enthesitis, and joint threshold that measure requires, along with the fact that MDA differentiates less cleanly when comparing two highly effective active agents rather than a drug against placebo. The combined ACR50 plus PASI100 response also fell short of significance (nominal p=.08). However, an early ACR50 assessment at week 4 showed clear separation between the two drugs, reflecting bimekizumab's faster onset of action, while PASI100 skin clearance alone was similar between arms, highlighting that both mechanisms deliver strong skin outcomes. DAPSA low disease activity or remission, a joint-centric composite measure, favored bimekizumab meaningfully, at 65.3% versus 54.7% (nominal p=.0066). On safety, Dr. Mease notes that both agents performed in line with their individual clinical trial histories, with no major signal for serious infection, malignancy, or major adverse cardiovascular events. A small percentage of bimekizumab-treated patients experienced mild, easily treated oral candidiasis that did not tend to recur, and there was a single case of inflammatory bowel disease in the bimekizumab arm; rates of severe treatment-emergent adverse events were low and comparable between the two groups.

These findings will be explored in greater depth in the next segment, where Dr. Mease and Dr. Khattri unpack what this efficacy and safety data means for treatment selection in clinical practice.