LAUSR

OBJECTIVES 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.