Cost Effectiveness and Budget Impact of Siponimod Compared to Interferon Beta-1a in the Treatment of Adult Patients with Secondary Progressive Multiple Sclerosis with Active Disease in Switzerland

Objective The study aim was to evaluate the cost effectiveness and budget impact of siponimod compared to interferon beta-1a for adult patients with secondary progressive multiple sclerosis (SPMS) with active disease, from a Swiss health insurance perspective. Methods We conducted an analysis using a Markov cohort model with a cycle length of 1 year, life-long time horizon, and discount rate of 3% for cost and health outcomes. We used a matching-adjusted indirect comparison to estimate clinical outcomes using data from the EXPAND randomised controlled trial of siponimod vs placebo and the Nordic SPMS randomised controlled trial of interferon beta-1a vs placebo as the basis for estimates of disability progression and relapse outcomes. We used 6-month confirmed disability progression results to estimate disability progression in the base-case analysis. We calculated quality-adjusted life-years (QALYs) based on an external study that administered the EQ-5D-3L questionnaire to European patients with multiple sclerosis. We included costs (Swiss Franc (CHF), year 2020) of drug acquisition/administration, adverse events and disease management. We also performed a budget impact analysis to estimate the cost over the first 3 years of introducing siponimod. Results For the base case, siponimod resulted in mean incremental costs of CHF 84,901 (siponimod: CHF 567,838, interferon beta-1a: CHF 482,937) and mean incremental QALYs of 1.591 (siponimod: 7.495, interferon beta-1a: 5.905), leading to an incremental cost-effectiveness ratio of CHF 53,364 per QALY gained. In the probabilistic sensitivity analysis, the probability of the cost effectiveness of siponimod assuming a willingness-to-pay threshold of CHF 100,000 per QALY gained was 90%. Siponimod was projected to result in drug administration costs for siponimod of CHF 23,817,856 in the first 3 years after introduction, accompanied by large cost offsets in drug acquisition of other multiple sclerosis drugs. Considering drug administration, monitoring and adverse event management costs, it was estimated to result in additional healthcare costs in Switzerland of CHF 2,177,021. Conclusions In the base-case analysis, we found that siponimod may be cost effective for treating Swiss adult patients with SPMS with active disease. The results of the cost-effectiveness analyses are valid under the assumption that the efficacy of siponimod and the comparators on disability progression for the overall SPMS population would be the same in the active SPMS population. Clinical Trial Identifier NCT01665144. This economic evaluation was based on the EXPAND trial.