Cost Effectiveness of Secukinumab for the Treatment of Active Ankylosing Spondylitis in the UK

Objective To determine the cost effectiveness of secukinumab, a fully human interleukin-17A inhibitor, for adults in the UK with active ankylosing spondylitis (AS) who have not responded adequately to previous treatment with conventional care (CC; biologic-naïve population) or previous biologic therapy (biologic-experienced population). Perspective and Setting UK National Health Service (NHS). Methods The model was structured as a 3-month decision tree leading into a Markov model. Comparators were licensed tumour necrosis factor inhibitors (including available biosimilars) and CC in the biologic-naïve and biologic-experienced populations, respectively. Clinical parameters captured treatment response, short-term disease activity and patient functioning, as well as long-term structural disease progression. Utilities were derived from secukinumab trial data. List prices were used for all drugs. The cost year was 2017 and costs and outcomes were discounted at 3.5%. Results In the biologic-naïve population, secukinumab dominated adalimumab and certolizumab pegol. Incremental cost-effectiveness ratios (ICERs) versus other comparators were either below £10,000 per quality-adjusted life-year (QALY) gained or south-west ICERs that implied cost effectiveness of secukinumab. In biologic-experienced patients, the ICER for secukinumab versus CC was £4927 per QALY gained. Treatment response rates, short-term treatment effects, long-term radiographic progression and biologic acquisition costs were key model drivers. Scenario analysis found results to be robust to changes in model structural assumptions. Probabilistic analysis identified greater uncertainty in results in the biologic-naïve population. Conclusions Even at list price, secukinumab appears to represent a cost-effective use of NHS resources for biologic-naïve and biologic-experienced patients with active AS. Further research on long-term radiographic progression outcomes would be valuable for future cost-effectiveness analyses in AS.