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.