Abstract
BACKGROUND: Multiple sclerosis (MS) is a heterogeneous disease that may manifest differently among racial/ethnic groups, influencing response to disease-modifying therapy (DMT). Data on natalizumab (NTZ) effectiveness in people with MS (PwMS) based on race/ethnicity are limited. OBJECTIVE: The aim of this study was to evaluate the effectiveness of NTZ on relapse onset and rate, and to assess MS-related healthcare encounters and costs in Black, Hispanic, Asian, and White PwMS. METHODS: This was a retrospective analysis of the Komodo Health Claims Database, including adult patients in the US with one or more MS claim at index date (January 1, 2016-August 31, 2022). Patients were followed from first NTZ exposure through end of study, end of insurance eligibility, gap in index DMT > 45 days, or DMT switch. Annualized relapse rate (ARR), time to first relapse, and MS-related healthcare encounters and costs were compared in the 12 months pre/post NTZ initiation and while on treatment across racial strata. RESULTS: The study included 3244 PwMS (Black, n = 632; Hispanic, n = 382; Asian, n = 49; White, n = 2181). Mean post-index NTZ exposure was 15.5-19.2 months. Post-index ARRs were significantly reduced across racial/ethnic groups (p < 0.001). The adjusted Kaplan-Meier estimated proportion of relapse-free patients at 2 years for all racial/ethnic groups was not significantly different from the White group. Significant differences were observed in annualized MS-related healthcare cost rates but not in annualized MS-related encounter rates before and after NTZ initiation across the racial/ethnic groups. CONCLUSION: NTZ was effective across racial/ethnic groups although not significantly different between groups.