OBJECTIVES: Biologic therapy has been successfully adopted for the treatment of patients with ankylosing spondylitis (AS). Several biologics are currently licensed in AS in Portugal including etanercept, infliximab, adalimumab, golimumab, certolizumab pegol and secukinumab. We aimed to assess the cost-effectiveness of secukinumab in AS biologic-naive patients from the Portuguese National Healthcare Service (NHS) perspective.

METHODS: A decision analytic model (semi-Markov) was developed to evaluate the cost-effectiveness of secukinumab 150mg over a lifetime horizon (60 years) against other biologics, with the exception of infliximab, which is not a first-line anti-TNF in the context of the Portuguese current clinical practice. Model clinical inputs (short- and long-term changes in Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] and in Bath Ankylosing Spondylitis Functional Index [BASFI], withdrawal rates, adverse events, resource use, costs, utilities and disutilities) were obtained from clinical trials, literature and expert’s opinion, and national official sources. Benefits were expressed as quality-adjusted life years (QALYs). Costs were expressed in 2019 Euros. Incremental cost per QALY gained was estimated considering an annual discount rate of 5% for costs and benefits. Sensitivity analyses were performed.

RESULTS: Over a lifetime horizon, the model predicted that patients treated with secukinumab 150mg achieve the highest benefit (10.03 QALYs) at the lowest cost (€191,182) versus etanercept (9.28 QALYs; €214,547), adalimumab (9.59 QALYs; €206,259), certolizumab (9.72 QALYs; €214,373) and golimumab (9.94 QALYs; €211,435). Therefore, secukinumab dominated all comparators. In all treatments, about half of the cost is related with the acquisition of the biologic drug. Probabilistic sensitivity analysis showed that secukinumab demonstrated higher probability of achieving maximum net monetary benefit versus comparators at a threshold of €30,000/QALY.

CONCLUSIONS: This analysis indicates that secukinumab is the most cost-effective treatment option for biologic-naive AS patients in Portugal. Treatment of AS with secukinumab may thus result in relevant benefits for patients and higher efficiency for the NHS.