Long-Term Uveitis Rates with Bimekizumab Treatment Across Pooled Phase 2B and Phase 3 Studies in Patients with Axial Spondyloarthritis or Psoriatic Arthritis: 3-Year Update

Objectives To report updated uveitis incidence in bimekizumab (BKZ)-treated patients with axial spondyloarthritis (axSpA) or psoriatic arthritis (PsA) in Phase 2b/3 studies over a treatment duration of 3 years in Phase 3 studies. Methods Data are reported for 2 pools, each comprising 1 Phase 2b and 2 Phase 3 studies and their open-label extensions, in patients with axSpA and PsA, respectively (data cut-off in axSpA: September 2024; PsA: August 2024). Uveitis events were identified using the preferred terms “autoimmune uveitis”, “iridocyclitis”, “iritis”, and “uveitis”, classified using the MedDRA v19.0; “acute anterior uveitis” was not a specific preferred term available in MedDRA v19.0. Uveitis rates and exposure-adjusted incidence rates (EAIR) per 100 patient-years (PY) for patients who received ≥1 BKZ 160 mg every 4 weeks (Q4W) dose are reported separately for axSpA and PsA, respectively. Results Patients with axSpA (N=848) and PsA (N=1,409) had a mean (standard deviation [SD]) age of 40.3 (11.9) and 49.3 (12.4) years, respectively. Mean (SD) time since diagnosis was 6.1 (7.8) years in patients with axSpA and 7.0 (8.0) in patients with PsA. Of patients with axSpA, 130 (15.3%) had a history of uveitis (PsA: 21 [1.5%]). Most patients with axSpA were HLA-B27 positive (717/848 [84.6%]). In patients with axSpA across the pooled Phase 2b/3 data, BKZ exposure was 2,748.9 PY. In total, uveitis occurred in 33/848 (3.9%; EAIR [95% CI]: 1.2/100 PY [0.8, 1.7]) patients overall and in 20/130 (15.4%; 5.0/100 PY [3.0, 7.7]) patients with history of uveitis. In patients without a history of uveitis, 13/718 (1.8%; 0.6/100 PY [0.3, 1.0]) patients had uveitis events (Figure 1). Most events were mild/moderate, 1 was severe; 2 (0.2%) patients discontinued treatment due to uveitis. Incidence of uveitis in patients with PsA was low across the pooled Phase 2b/3 data (total BKZ exposure: 4,264.7 PY); uveitis occurred in 4/1,409 (0.3%; 0.1/100 PY [0.0, 0.2]) patients overall; 2 had a history of uveitis. No uveitis events led to treatment discontinuation. Figure 1. Incidence of uveitis in patients with axSpA stratified by history of uveitis Conclusion Over 3 years of BKZ treatment, the incidence of uveitis in patients with spondyloarthritis receiving BKZ long-term was low.