To evaluate the cost-effectiveness of secukinumab, a fully human anti-interleukin-17A monoclonal antibody, compared to other clinically used biologics (adalimumab, infliximab, and ustekinumab) in Japan for the treatment of moderate-to-severe psoriasis from the healthcare system (total costs) and patient co-payment (using different frequencies of drug purchase) perspectives.
A decision-tree (first year)/Markov model (subsequent years), with an annual cycle, was developed. The model adopted a 5-year time horizon. Efficacy inputs were obtained from a mixed-treatment comparison analysis, and other model inputs were collected from published literature and local Japanese sources. Model outcomes included quality-adjusted life years (QALYs) and an incremental cost-effectiveness ratio (ICER) in terms of cost per QALY gained. The annual discounting rate of 2% was applied to both costs and outcomes.
Results for the healthcare system perspective showed that secukinumab had the highest number of quality-adjusted life years (QALYs) (4.07) vs other biologics, dominated ustekinumab and infliximab, and the ICER of secukinumab compared to adalimumab was ¥8,418,222/QALY gained. In the patient co-payment perspective with the monthly purchase of drugs, ustekinumab had the lowest co-payment cost, followed by infliximab, adalimumab, and secukinumab. In the patient co-payment perspective with a once every 3 months purchase of secukinumab and adalimumab, the co-payment costs of secukinumab, adalimumab, and ustekinumab became comparable, and infliximab had the highest co-payment cost.
Only short-term efficacy data was modeled, as there was a lack of data on long-term outcomes. Treatment sequencing was restricted to first-line biologic treatment. Drop-out rates for comparators were assumed to be equivalent to secukinumab in the absence of available data.
Secukinumab is a cost-efficient treatment for moderate-to-severe psoriasis, providing greater health outcomes to patients at lower total costs compared to infliximab and ustekinumab, as well as comparable patient co-payment relative to other biologic treatments.