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.