Objective: Evaluating the efficacy and safety of ritixumab compared to ocrelizumab in the treatmens of RMS. Study design: Randomized double blind multi-centre non-inferiority study of rituximab compared to ocrelizumab in 200 patients with RMS. The trial duration will be 30 months Study population: The study population consists of 200 adult RMS patiens with an indication to start anti-CD20 monoclonal antibody treatment. Intervention: Patients will be randomized 1:1 into the standard group (ocrelizumab treatment) or the experimental group (rituximab treatment). Main study parameters: To conclude non-inferiority of rituximab there will be one primary endpoint: the proportion of patients free of inflammatory disease activity (defined as: new or enlarged T2 lesions) between week 24 (M6) and week 96 (M24) of treatment in each arm. Secondary trial endpoints are presence and number of clinical relapses,T2 and contrast enhancing lesion volumes, brain volume and brain volume changes, disease progression (defined as clinically relevant change on any of the measures: EDSS, T25FW, 9HPT, SDMT), biochemical parameters such as lipidomics and neurofilament light (NfL), immunological parameters, safety as measured by the number of (serious) adverse events ((S)AE), quality of life (EQ-5D-L) and treatment satisfaction (TSQM) and patient reported measures of MS impact (MSIS-29) and well-being (questionnaire on physical complaints) Nature and extent of the burden and risk: Patients included in this study will be treated and monitored by MRI, clinical tests and laboratory tests according to existing protocols and will not be exposed to extra or unknown risks. They will have extra annual questionnaires and larger blood samples at some time points. There is extensive experience with both rituximab and ocrelizumab as efficacious and safe treatments of RMS.