• 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