Treatment persistence and clinical outcomes in patients starting B cell depleting therapies within the Swiss MS Cohort

Background: Persistence to B cell depleting therapies (BCDT) like ocrelizumab and rituximab may be higher compared with other disease-modifying therapies (DMT) in multiple sclerosis (MS). Clinical trials directly comparing these treatments are lacking. Objective: To compare the risk of treatment discontinuation, relapse, and confirmed disability worsening in patients starting BCDT vs other DMT within real-world settings. Methods: In a longitudinal cohort study, patients with relapsing MS starting BCDT (ocrelizumab/rituximab, n = 269) after enrolment into the Swiss MS Cohort (SMSC) were evaluated for treatment discontinuation, occurrence of relapses, and disability worsening in comparison with platform ( n = 57) and oral ( n = 454) DMT, or natalizumab ( n = 73) using Cox regression with double robust adjustment for baseline covariates. Results: Patients starting BCDT were less likely to discontinue treatment than all other DMT combined (HR = 0.26, 95% CI = 0.18–0.36, p < .01), oral DMT (HR = 0.28, 95% CI = 0.20–0.39, p < .01) and natalizumab (HR = 0.35, 95% CI = 0.21–0.58, p < .01). BCDT were associated with lower risk of relapses as compared to oral DMT HR = 0.59, 95% CI = 0.39–0.88, p < .01), but not to natalizumab (HR = 0.90, 95% CI = 0.45–1.82, p = .778). Disability worsening was not significantly different between treatment groups. Conclusion We provide real-world evidence for patients being more persistent to BCDT than to other treatments, and better clinical outcomes may partly explain this.