Ocrelizumab treatment and disability progression in non-Hispanic Black and Hispanic or Latino individuals with relapsing multiple sclerosis: A post hoc analysis of the OPERA I and II trials

Background: Racial and ethnic disparities are evident in multiple sclerosis. Objectives: To assess whether disease progression and treatment response differ between non-Hispanic Black or Hispanic/Latino and non-Hispanic White people with relapsing multiple sclerosis. Methods: This post hoc analysis included people with relapsing multiple sclerosis from ocrelizumab trials (NCT01247324/NCT01412333) self-reporting as non-Hispanic Black ( n = 65), Hispanic/Latino ( n = 213), or non-Hispanic White ( n = 1350). Genetic ancestry was analyzed for consenting participants ( n = 1138). In addition, 24-week composite confirmed disability progression risk and CD19 + B cells were compared between subgroups. Results: In the interferon beta-1a treatment arm, non-Hispanic Black and Hispanic/Latino people with relapsing multiple sclerosis had increased 24-week cCDP risk compared with non-Hispanic White people with relapsing multiple sclerosis (hazard ratio (95% confidence interval) non-Hispanic Black: 3.0 (1.4–6.5); p = 0.005; Hispanic/Latino: 2.3 (1.6–3.4); p < 0.001). Composite confirmed disability progression risk was greater in people with relapsing multiple sclerosis with higher African (hazard ratio: 4.4 (1.7–11.2); p = 0.002) or Americas ancestry (hazard ratio: 5.8 [2.7–12.4]; p < 0.001) than European ancestry. Non-Hispanic Black and Hispanic/Latino people with relapsing multiple sclerosis had increased baseline CD19 + B cells. Compared with interferon beta-1a, ocrelizumab reduced B cells in all groups ( p < 0.001) and decreased composite confirmed disability progression risk in all people with relapsing multiple sclerosis, including non-Hispanic Black (hazard ratio: 0.41 (0.13–1.29); p = 0.13) and Hispanic/Latino (hazard ratio: 0.38 (0.20–0.72); p = 0.003). Conclusion: Compared with non-Hispanic White people, non-Hispanic Black and Hispanic/Latino people with relapsing multiple sclerosis showed higher disease progression risk. Ocrelizumab reduced composite confirmed disability progression risk in people with relapsing multiple sclerosis regardless of race, ethnicity, or genetic ancestry.