Real-World Healthcare Cost Savings and Reduced Relapse Rate with Off-Label Rituximab versus Disease-Modifying Treatments Approved for Relapsing-Remitting Multiple Sclerosis: A Nationwide Cost-Effectiveness Study.

Abstract

Although off-label use of rituximab is a common alternative to disease-modifying therapies (DMTs) approved for multiple sclerosis (MS) in several countries, the impact of this on treatment cost-effectiveness is not well known. We evaluated the relative cost-effectiveness of rituximab and MS-approved DMTs in a register-based cohort study of Swedish residents with relapsing-remitting MS, aged 18-65 years, starting treatment with rituximab, natalizumab, fingolimod, or dimethyl fumarate between January 2010 and July 2016, and followed through July 2021 (n = 5,924). By linking the population-based Swedish MS register to several Swedish health care and demographic registers, we estimated health care costs in relation to number of relapses, over 5 years from treatment start. Differences between treatments were estimated in inverse probability of treatment-weighted regression models, adjusting for a broad range of potential confounders covering demographics, medical history, and MS-related clinical characteristics. Off-label rituximab was associated with both lower total health care costs (mean cost savings ranged $35,000-$66,000 vs. each approved DMT), and fewer relapses (mean number of prevented relapses ranged 0.12-0.22), per started therapy over 5 years. Results were robust to variations in discounting and pricing of health care visits, with the main driver of cost-savings being the price of the index drug itself. The cost-effectiveness of rituximab dominated the MS-approved alternatives. Off-label, low-dose rituximab should be considered for persons with MS and could reduce barriers to treatment, especially in resource-limited settings. ANN NEUROL 2024;95:1099-1111.