BMI influences CD20 kinetics in multiple sclerosis patients treated with ocrelizumab.

• Effectiveness of ocrelizumab is confirmed in clinical practice. • Higher BMI could influence CD20 repopulation after the treatment with Ocrelizumab. • Lymphocytes and immunoglobulins m reduce during anti-CD20 therapy with no effect on safety on the short follow up. Ocrelizumab (OCR) is a humanized monoclonal antibody targeting CD20 antigen exposed on B cells surface. Kinetic of B-cells repopulation after depletion therapy shows high intra and inter-individual variability. The aim of this study was to explore the influence of Body Mass Index (BMI) on kinetic of B-cell repopulation after treatment with OCR and on treatment response. 108 Multiple Sclerosis (MS) patients were enrolled at the time of the first dose of OCR administration and prospectively evaluated. Clinical, instrumental activity and disability progression were analyzed. According to B cells count, patients were divided into two groups: with fast (FR) and with slow (SR) repopulation rate, respectively. Significant reduction of disease activity was observed in all patients and a stabilization of disease was obtained in progressive patients. Patients with FR had higher BMI compared to patients with a SR (p <0.001). Contrariwise no correlation between repopulation rate and treatment effectiveness was disclosed. In a real world setting we confirmed the effectiveness of OCR in relapsing remitting and progressive patients; patients with higher BMI had a FR. This suggests considering BMI for administration schedule although further investigations with longer follow up could improve treatment protocol and patient selection. [ABSTRACT FROM AUTHOR]