RItuximab Versus Ocrelizumab in Relapsing-remitting Multiple Sclerosis.

The goal of this randomized clinical trial is to compare relapse remitting multiple sclerosis (RRMS) patients treated by ocrelizumab or by rituximab followed for 2 years. The main question it aims to answer is : • to demonstrate the non-inferiority of rituximab versus ocrelizumab in active relapsing MS patients on the % of patients without disease activity at 2 years. During the 2 years, the study includes 6 follow-up visits and the completion of various health and quality of life questionnaires. The protocol visits follow the usual schedule of treatment infusions for the disease (at initiation of treatment, 15 days after, and then every 6 months). Two comparison groups: Researchers will compare rituximab treated patients versus ocrelizumab treated patients to see the % of patients without disease activity at 2 years.

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS). This disease is the leading cause of non-traumatic disability in young adults and France is characterized by a high prevalence (currently 1/1000 inhabitants) of MS. Clinical trials with B cell depleting therapies have shown efficacy in relapsing-remitting MS (RRMS) and are increasingly perceived as an important addition to the existing panel of Disease-modifying treatments (DMTs). Rituximab, a mouse chimeric anti CD20, is approved for non-Hodgkin's lymphoma, chronic lymphocytic leukemia, certain forms of vasculitis and Rheumatoid Arthritis with first marketing approval in 1998. Rituximab has undergone clinical testing in RRMS in 2008 in a phase II placebo-controlled trial, demonstrating the clinico-radiological efficacy in 104 patients. Despite these promising results and the absence of adverse events, its clinical development was interrupted by the manufacturer (Roche). However, for several years, rituximab has been increasingly prescribed (off-label) in Europe and USA in patients refractory to first-line therapies, with a very good safety and efficacy. Thus, rituximab is prescribed for 40% of RRMS patients treated in Sweden. Roche has then developed a humanized anti-CD20 monoclonal antibody (Ocrelizumab). Two phase III clinical trials (OPERA I and II) have demonstrated its efficacy in active RRMS. Ocrelizumab has just been authorized in France in this indication: RRMS patients with active disease (clinical or radiological). So, it can be prescribed as a first line or second line therapy in active RRMS patients. According to literature, there are no biological arguments to think that ocrelizumab could be more effective in active RRMS compared to rituximab. Moreover, regarding safety, rituximab has been used for other indications for almost two decades and no serious concern has arisen. The high cost of this new antibody (x6 to 10) compared to rituximab) makes it wonder about its place inside the anti-CD20 therapeutic strategy compared to rituximab for treating relapsing MS patients. Hypothesis: Researchers hypothesize that rituximab and ocrelizumab have the same efficacy in active RRMS patients. Indeed, if the non-inferiority of rituximab on the % of patients without disease activity is confirmed by the trial, the potential medico-economic benefit from a societal perspective will be a strong argument to ask for authorization of rituximab in active RRMS.