Objectives: To assess the cost-effectiveness of bimekizumab compared to secukinumab for patients with axial spondyloarthritis (axSpA) in Greece, including both non-radiographic axSpA (nr-axSpA) and radiographic axSpA (r-axSpA) populations.

Methods: The analysis utilized a previously peer-reviewed and published decision tree model for the first year and a Markov state-transition model for subsequent years, adapted for a lifetime horizon of 75 years. The Ankylosing Spondylitis Disease Activity Score (ASDAS) was used to measure treatment response, consistent with Greek therapeutic guidelines. The analysis included adult patients with active nr-axSpA and r-axSpA who showed objective signs of inflammation and had an inadequate response to nonsteroidal anti-inflammatory drugs (NSAIDs) (biologic-naïve patients). For nr-axSpA, secukinumab 150mg was used, while a dose of 300mg was used in r-axSpA patients, based on clinical expert estimates indicating that up to 60% of patients would receive the higher dose. Direct costs, including those for drug acquisition, administration, monitoring, disease management, and adverse events, were considered (€,2023). Outcomes were expressed as incremental cost-effectiveness ratios (ICER), over a willingness-to-pay threshold of €51,000 in Greece, considering differences in quality-adjusted life-years (QALY) gained and costs. Extensive sensitivity analyses were conducted to assess variations in input data.

Results: For patients with nr-axSpA, bimekizumab was found to be more effective (+0.31 QALYs) and more costly (+€10,985), resulting in an ICER of €34,893 per QALY gained compared to secukinumab 150mg. For r-axSpA patients, the ICER was €53,087 per QALY gained when comparing bimekizumab to secukinumab 300mg (+00.14 QALYs, +€7,244). Sensitivity analyses confirmed the cost-effectiveness of BKZ in two populations.

Conclusions: Bimekizumab seems to be a valuable addition to the therapeutic arsenal, for managing patients with axSpA in Greece. The analysis indicates that bimekizumab represents a cost-effective treatment option due its additional therapeutic benefits, despite the higher incremental costs.