Comparative effectiveness of rituximab versus ocrelizumab in relapsing multiple sclerosis on clinical relapses and radiological outcomes in British Columbia, Canada.

BACKGROUND

Recent research has suggested that rituximab is not non-inferior to ocrelizumab in the treatment of relapsing multiple sclerosis (RMS). We compared the effectiveness of rituximab versus ocrelizumab in RMS.

METHODS

Individuals with RMS treated with rituximab or ocrelizumab with ⩾12 months of clinical follow-up and/or post-rebaseline magnetic resonance imaging (MRI) data were propensity-scored matched 1:1 and included.

OBJECTIVES

Primary outcomes were annualized relapse rate (ARR), ARR ratio and cumulative hazard of relapses. The secondary outcome was the proportion of each group demonstrating post-rebaseline radiological activity.

RESULTS

In total, 538 individuals were included in the primary (clinical) outcome analysis and 350 individuals were included in the secondary (radiologic) outcome analysis. Over a median 2-year follow-up, very low ARR was observed in both groups (rituximab: 0.05 (95% CI: 0.03-0.08) versus ocrelizumab: 0.03 (95% CI: 0.02-0.05)). The adjusted ARR ratio for rituximab compared with ocrelizumab was elevated at 1.76 (95% CI: 0.70-4.59), and the adjusted cumulative hazard of relapses was also elevated for rituximab-treated individuals (HR = 2.17 (95% CI: 0.91-5.1)).

CONCLUSION

Although our results suggest that rituximab may be inferior to ocrelizumab for relapse suppression, the rarity of relapses underpowered comparisons, and no definitive conclusions could be drawn.