PO:03:033 | Low Uveitis Rates in Patients with Axial Spondyloarthritis or Psoriatic Arthritis Treated with Bimekizumab: Long-Term Results from Phase 2b/3 Trials

Irene E Van Der Horst-Bruinsma¹, Matthew A Brown², Floris A Van Gaalen³, Nigil Haroon⁴, Lianne S Gensler⁵, Alexander Marten⁶, Myriam Manente⁷, George Stojan⁸, Thomas Vaux⁹, Katy White⁹, Atul Deodhar¹⁰, Nicola Boffini¹¹, Martin Rudwaleit¹² | ¹Department of Rheumatology, Radboud University Medical Centre Nijmegen, The Netherlands; ²Genomics England London, United Kingdom; ³Department of Rheumatology, Leiden University Medical Center Leiden, The Netherlands; ⁴Department of Medicine/Rheumatology, University Health Network, Schroeder Arthritis Institute, University of Toronto Toronto, Canada; ⁵Department of Medicine/Rheumatology, University of California San Francisco, USA; ⁶UCB Monheim am Rhein Germany; ⁷UCB Braine-lAlleud, Belgium; ⁸UCB Atlanta, USA; ⁹UCB Slough, United Kingdom; ¹⁰Division of Arthritis and Rheumatic Diseases, Oregon Health and Science University Portland, USA; ¹¹IRCCS Ospedale San Raffaele Milan, Italy; ¹²Klinikum Bielefeld, University of Bielefeld, Bielefeld, Germany

Purpose of the Work. Acute anterior uveitis (‘uveitis’) is a common extra-musculoskeletal manifestation in patients (pts) with spondyloarthritis (SpA), and incidence varies with SpA type and disease duration.[1,2,3] Interleukin (IL)-17 has been implicated in the pathogenesis of uveitis; however, previous data have not demonstrated efficacy for IL-17A inhibition alone in managing the condition.[4,5] The exposure-adjusted incidence rate (EAIR) per 100 pt-years (PY) of uveitis was lower in patients (pts) with axial SpA (axSpA) randomised to bimekizumab (BKZ; 1.8/100 PY), a dual IL-17A/F inhibitor, versus placebo (15.4/100 PY) after 16 weeks.[6] Here, we report long-term incidence of uveitis following BKZ treatment in axSpA or psoriatic arthritis (PsA) pts.

Materials and Methods. Safety data are reported for two pools, each comprising three phase 2b/3 (ph2b/3) studies and their open-label extensions, in pts with active axSpA (non-radiographic and radiographic axSpA) and active PsA, respectively (Figure 1). Uveitis events were identified using the preferred terms “autoimmune uveitis”, “iridocyclitis”, “iritis”, and “uveitis”, coded according to MedDRA v19.0; note that “acute anterior uveitis” was not a specific preferred term available in MedDRA v19.0. Uveitis rates and EAIRs/100 PY for pts who received >=1 BKZ 160 mg dose are reported (data cut-off: July 2023).

Results. Pts with axSpA (N=848) had a mean age (standard deviation [SD]) of 40.3 (11.9) years, and pts with PsA (N=1,409) had a mean age (SD) of 49.3 (12.4) years, with a mean time since diagnosis (SD) of 6.1 (7.8) and 7.0 (8.0) years, respectively. Of pts with axSpA, 130 (15.3%) had a history of uveitis; 21 (1.5%) pts with PsA had a history of uveitis. The majority of pts with axSpA were human leukocyte antigen (HLA)-B27 positive (717/848 [84.6%]). In pts with axSpA across the pooled ph2b/3 axSpA trial data, BKZ exposure was 2,514 PY. Uveitis occurred in 31/848 (3.7%; EAIR [95% confidence interval; CI]: 1.3/100 PY [0.9, 1.8]) pts overall and in 18/130 (13.8%; 4.8/100 PY [2.8, 7.6]) pts with history of uveitis. In pts without a history of uveitis, 13/718 (1.8%; 0.6/100 PY [0.3, 1.1]) pts had uveitis events (Figure 2). All events were mild/moderate, one led to treatment discontinuation. Incidence of uveitis in pts with PsA was low across the pooled ph2b/3 PsA trial data (total BKZ exposure: 3,656 PY); uveitis occurred in three (0.2%; 0.1/100 PY [0.0, 0.2]) pts overall; one had history of uveitis. No uveitis events led to treatment discontinuation.

Conclusions. Across 2,514 PY in pts with axSpA and 3,656 PY in pts with PsA, the long-term data suggest that the incidence of uveitis in pts treated with BKZ remains low.