OBJECTIVES: To utilize real-world data from the MSBase Registry to estimate the cost-effectiveness of switching to natalizumab (NAT) compared with switching to fingolimod (FTY) in patients with highly-active relapsing-remitting multiple sclerosis (HA-RRMS) with inadequate response to first-line therapies (BRACE-TD) in Spain.

METHODS: The analysis was based on a previously developed Markov model adapted to the Spanish healthcare payer perspective. The model used health states based on the Expanded Disability Status Scale (EDSS) to capture RRMS disability changes, conversion to secondary progressive MS, and associated relapses. The primary clinical data (EDSS transition matrices, relapse rates, and comparative effectiveness for NAT and FTY) were obtained from MSBase. Local Spanish data were used for treatment, disease management, relapse, and adverse event costs; utilities; and general mortality. Other data were obtained from published literature and publicly available sources. The analysis estimated lifetime clinical and economic outcomes and the incremental cost per quality-adjusted life-year (QALY) gained from a healthcare payer perspective. The impact of alternative model settings and parameter uncertainty was evaluated through scenario and sensitivity analyses.

RESULTS: In the base-case analysis, NAT dominated FTY, leading to higher QALYs (0.434 higher per patient) and lower costs (€11,132 lower per patient); NAT remained dominant at up to a 12.2% discount on the FTY list price. In scenario analysis, NAT remained dominant except when a 10-year horizon was considered. In probabilistic sensitivity analysis, NAT was dominant in 85.8% of simulations and had a 94.2% probability of being cost-effective at a willingness-to-pay threshold of €30,000/QALY gained.

CONCLUSIONS: This analysis utilising real-world comparative effectiveness data from MSBase estimated that switching to NAT was more effective and less costly than switching to FTY in HA-RRMS patients with inadequate response to BRACE-TD in Spain. Sensitivity analyses suggested that NAT was likely to remain dominant across a range of alternative scenarios.