Low uveitis rates in patients with axial spondyloarthritis treated with bimekizumab: pooled results from phase 2b/3 trials

Objectives Acute anterior uveitis (‘uveitis’) is a common axial spondyloarthritis (axSpA) extramusculoskeletal manifestation. Interleukin (IL)-17 is implicated in its pathogenesis, however, there is conflicting evidence for IL-17A inhibition in uveitis management. We report pooled analyses of uveitis incidence in patients receiving bimekizumab (BKZ), a monoclonal IgG1 antibody that selectively inhibits IL-17F in addition to IL-17A, from phase 2b/3 trials. Methods Data were pooled for patients receiving BKZ 160 mg or placebo in the double-blind treatment period of the phase 3 BE MOBILE 1 ( NCT03928704 ; non-radiographic axSpA) and BE MOBILE 2 ( NCT03928743 ; radiographic axSpA) trials. Data were separately pooled for patients treated with at least one BKZ dose in the BE MOBILE trials and their ongoing open-label extension (OLE; NCT04436640 ), and the phase 2b BE AGILE trial ( NCT02963506 ; radiographic axSpA) and its ongoing OLE ( NCT03355573 ). Uveitis rates and exposure-adjusted incidence rates (EAIR)/100 patient-years (PYs) are reported. Results In the BE MOBILE 1 and 2 double-blind treatment period, 0.6% (2/349) of patients receiving BKZ experienced uveitis vs 4.6% (11/237) receiving placebo (nominal p=0.001; EAIR (95% CI): 1.8/100 PYs (0.2 to 6.7) vs 15.4/100 PYs (95% CI 7.7 to 27.5)). In patients with history of uveitis, EAIR was lower in patients receiving BKZ (6.2/100 PYs (95% CI 0.2 to 34.8); 1.9%) vs placebo (70.4/100 PYs (95% CI 32.2 to 133.7); 20.0%; nominal p=0.004). In the phase 2b/3 pool (N=848; BKZ exposure: 2034.4 PYs), EAIR remained low (1.2/100 PYs (95% CI 0.8 to 1.8)). Conclusions Bimekizumab, a dual-IL-17A/F inhibitor, may confer protective effects for uveitis in patients with axSpA.