RItuximab Versus Ocrelizumab in Relapsing-remitting Multiple Sclerosis.

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.