Predictors of B-cell repopulation in people with multiple sclerosis treated with ocrelizumab: insights from two large cohorts.

BACKGROUND: Evidence indicates that B-cell dynamics during ocrelizumab treatment vary among individuals with multiple sclerosis. However, our understanding of B-cell dynamics is incomplete. We aim to characterise temporal profiles of CD19+ B-cell repopulation and identify demographic and clinical predictors of B-cell dynamics. METHODS: cells/L, 150-210 days post infusion). We have explored the patterns of early B-cell repopulation and relapse incidence within these groups. RESULTS: cells/L (IQR=0.02-0.13)). Early B-cell repopulation was more likely in patients with prior early repopulation (OR=3.00, 95% CI 1.61 to 5.61). Relapse incidence did not differ between the four patterns of B-cell repopulation dynamics. CONCLUSIONS: Age, weight, cumulative ocrelizumab exposure, pre-ocrelizumab CD19+ B-cell count and prior disease modifying therapy influence CD19+ B-cell repopulation during ocrelizumab treatment. With further elucidation of the association between B-cell dynamics and treatment effectiveness, these findings will help guide dosing of anti-CD20 therapies in the future.