TRIO

Treatment tested

• Perfusion of treatment Rituximab
• Rituximab

  B-lymphocyte antigen CD20 binding agent

Compared with

• Perfusion of treatment Ocrelizumab
• Ocrelizumab

  B-lymphocyte antigen CD20 binding agent

Other measures (21)

Inclusion Criteria: * Patients presenting a relapsing remitting MS according to Mac Donald 2017 criteria, with clinical or radiological criteria of activity (ie at least one relapse AND/OR one new T2 lesion in the last 12 months before inclusion); * Age between 18 and 55 years * EDSS ≤ 5 * Brain MRI within 6 months before inclusion * For women of childbearing potential*: effective contraception (effective contraception include oral contraception, intrauterine devices and other forms of contraception with failure rate \<1%, for the duration of the study and until 12 months after last dose administered) * A woman is considered of childbearing potential (WOCBP), i.e. fertile, following menarche and until becoming post-menopausal unless permanently sterile. Permanent sterilisation methods include hysterectomy, bilateral salpingectomy and bilateral oophorectomy. A postmenopausal state is defined as no menses for 12 months without an alternative medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm a post-menopausal state in women not using hormonal contraception or hormonal replacement therapy. However, in the absence of 12 months of amenorrhea, a single FSH measurement is insufficient. * Having signed an informed consent form * Patients covered with social insurance Non-Inclusion Criteria: * Secondary or primary progressive MS; * Previous treatment by mitoxantrone, cladribine, alemtuzumab and anti CD20 therapies in the last two years; * Previous treatment by fingolimod or natalizumab in the last 4 weeks; * Treatment with high dose corticosteroids during the 30 days preceding the inclusion; * Occurrence of a relapse less than 30 days before inclusion; * Pregnancy or breastfeeding; * Other neurologic or systemic disease; * Concomitant participation or Participation in another therapeutic trial in the last 6 months; * Incapacity to understand or sign the consent form; * Contraindication to MRI; * Contraindication to anti-CD20 therapies: * Receipt of a live or live-attenuated vaccine within 6 weeks prior to randomization * Active malignancy. * Any ongoing infection * Severe heart failure (New York Heart Association Class IV) or severe uncontrolled cardiac disease * Positive test for HIV, hepatitis B or C, or tuberculosis * Severe immune deficiency: * Lymphopenia grade 3 (0.2 to 0.5 × 10\^9/L) or higher grades * Neutropenia grade 3 (0.5 to 1.0 × 10\^9/L) or higher grades * Known hypersensitivity or other known side effects for any of the study medications, including co-medications such as high glucocorticosteroids * AST or ALT >=3ULN * Platelet (thrombocyte) count \< 100 x 10\^9/L * Adults legally protected (under judicial protection, guardianship, or supervision), persons deprived of their liberty.

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.