Bimekizumab which provides dual inhibition of interleukin 17A and 17F significantly improved symptoms in those with axial spondyloarthritis
Use of bimekizumab in patients with both radiographic and non-radiographic axial spondyloarthritis produced significant and rapid improvements in disease outcomes in two parallel randomised trials by a European research group.
Axial spondyloarthritis (axSpA) represents a chronic inflammatory disease involving the axial skeleton that gives rise to chronic back pain and spinal stiffness but which may also include peripheral and extra-musculoskeletal manifestations. The term includes two forms of the condition, those with either radiographic and non-radiographic disease, with patients in this latter group representing those who are symptomatic but no evidence of definitive damage seen on pelvic radiographs.
It has become recognised that the interleukin-17A (IL-17A) pathway is implicated in the pathogenesis of axial spondyloarthritis although IL-17F has also been shown to induce similar inflammatory changes to IL-17 in joints. In fact, use of bimekizumab, which is a dual IL-17A and IL-17F blocker, is effective in psoriatic arthritis, which can also present with axial involvement in up to 50% of patients.
With data from a phase 2IIb trial in active ankylosing spondylitis, proving that bimekizumab was effective, in the current study, researchers undertook two parallel randomised, double-blind, placebo-controlled phase 3 trials of the drug in patients with both forms, i.e., non-radiographic (nr-disease) and radiographic (r-disease) axial spondyloarthritis. Participants with active nr-disease were randomised 1:1 and 2:1 (r-disease) to bimekizumab 160 mg every 4 weeks and from week 16 through to 52, all patients received bimekizumab 160 mg every 4 weeks. The primary endpoint was based on the Assessment of SpondyloArthritis international Society ≥40% improvement (ASAS40), i.e., a 40% improvement is disease severity.
Bimekizumab and disease improvement
At baseline virtually all patients (> 97.6%) had high or very high disease activity. In total, 254 patients with nr-disease and a mean age of 39.4 years (54.3% male) and 332 with r-disease and a mean age 40.1 years (72.2% male) with were included in the analysis.
At week 16, there was a significantly higher proportion of participants achieving an ASAS40 in both trials (nr-disease 47.7% vs 21.4% and r-disease 44.8% vs 22.5%, p<0.001 in both cases). Moreover, improvements became apparent within one to two weeks after starting bimekizumab in both trials.
The most frequent treatment emergent adverse events (i.e. occurring in > 3% of patients) with bimekizumab included nasopharyngitis, upper respiratory tract infection, pharyngitis, diarrhoea, headache and oral candidiasis.
The authors concluded that the use of the dual IL-17A and IL-17F inhibitor bimekizumab gave rise to significant and rapid improvements in patients with both radiographic and non-radiographic axial spondyloarthritis and was well tolerated.
van de Heijde D et al. Efficacy and safety of bimekizumab in axial spondyloarthritis: results of two parallel phase 3 randomised controlled trials. Ann Rheum Dis 2023