A Study of Efficacy and Safety of M2951 in Subjects With Relapsing Multiple Sclerosis

Inclusion Criteria:

- Subjects with a diagnosis of relapsing multiple sclerosis (may include subjects with
Secondary Progressive Multiple Sclerosis (SPMS) with superimposed relapses provided
they meet the other criteria) in accordance with revised McDonald criteria for MS and
Lublin and Reingold

- Male or female aged 18 to 65 years

- One or more documented relapses within the 2 years before Screening with either: a)
One relapse which occurred within the last year prior to randomization or b) the
presence of at least 1 Gd+ T1 lesion within 6 months prior to randomization would
make the patient eligible.

- Expanded Disability Status Scale score of 0 to 6 at Baseline

- Women of childbearing potential must use a supplementary barrier method together with
a highly effective method of contraception (according to International Council for
Harmonisation [ICH] guidance M3[R2]) for 4 weeks prior to randomization, throughout
the trial, and for 90 days after the last dose of IMP.

- Signed and dated informed consent (subject must be able to understand the informed
consent) indicating that the subject has been informed of all the pertinent aspects
of the trial prior to enrolment and will comply with the requirements of the
protocol.

Exclusion Criteria:

- Progressive MS

- Disease duration > 15 years in subjects with EDSS of 2 or less

- Use of the following, as determined in the protocol ; rituximab, ocrelizumab,
mitoxantrone, or lymphocyte-depleting therapies, lymphocyte trafficking blockers (eg,
natalizumab, fingolimod), intravenous (IV) immunoglobulins (Ig), plasmapheresis,
immunosuppressive treatments, B-interferons or glatiramer acetate, Systemic
glucocorticoids, teriflunomide

- Exposure to Tecfidera within 6 months prior to randomization

- Any allergy, contraindication, or inability to tolerate Tecfidera

- Treatment with dalfampridine (fampridine, Ampyra) unless on a stable dose for ≥ 30
days prior to randomization

- Inability to comply with MRI scanning

- Immunologic disorder other than MS, with the exception of secondary well-controlled
diabetes or thyroid disorder, or any other condition requiring oral, IV,
intramuscular, or intra-articular corticosteroid therapy

- Vaccination with live or live-attenuated virus vaccine within 1 month prior to
Screening

- Severe drug allergy or history of anaphylaxis, or allergy to the IMP or any of its
incipients

- Active, clinically significant viral, bacterial, or fungal infection, or any major
episode of infection requiring hospitalization or treatment with parenteral
anti-infectives within 4 weeks of Screening, or completion of oral anti-infectives
within 2 weeks before or during Screening, or a history of recurrent infections (ie,
3 or more of the same type of infection in a 12-month rolling period). Vaginal
candidiasis, onychomycosis, and genital or oral herpes simplex virus considered by
the Investigator to be sufficiently controlled would not be exclusionary.

- History of or positive testing for human immunodeficiency virus (HIV), hepatitis C
(HCV) antibody and/or polymerase chain reaction, hepatitis B surface antigen (HBsAg)
(+) and/or hepatitis B core total, and/or immunoglobulin M (IgM) antibody (+) at
Screening.

- The subject: • Has a history of or current diagnosis of active tuberculosis (TB) or •
Is currently undergoing treatment for latent TB infection (LTBI) or • Has an
untreated LTBI or • Has a positive QuantiFERON®-TB test at Screening.

- Indeterminate QuantiFERON®

- Subjects with current household contacts with active TB will also be excluded

- History of splenectomy or any major surgery within 2 months prior to Screening

- History of myocardial infarction or cerebrovascular event as per the protocol

- History of attempted suicide within 6 months prior to Screening or a positive
response to items 4 or 5 of Columbia-Suicide Severity Rating Scale (C-SSRS)

- An episode of major depression within the last 6 months prior to Screening

- On anticoagulation, fish oil supplements, or antiplatelet therapy other than daily
aspirin for cardioprotection and treatment of Tecfidera induced flushing

- History of cancer, except adequately treated basal cell or squamous cell carcinoma of
the skin

- Breastfeeding/lactating or pregnant women

- Participation in any investigational drug trial within 1 month or 5 half-lives of the
investigational drug, whichever is longest, prior to Screening

- Subjects currently receiving (or unable to stop using prior to receiving the first
dose of IMP) medications or herbal supplements known to be potent inhibitors of
cytochrome P450 3A (CYP3A)

- History of or current alcohol or substance abuse

- Clinically significant abnormality on electrocardiogram or screening chest X-ray

- Clinically significant laboratory abnormality