Determining the Effectiveness of earLy Intensive Versus Escalation Approaches for RRMS

Inclusion Criteria:

1. Men and women aged 18 to 60 years.

2. Established diagnosis of MS, as defined by the 2017 revision of McDonald DiagnosticCriteria (99).

3. RRMS disease course as defined by the 2013 revisions of the MS clinical coursedefinition (4).

4. Participants must have evidence of active disease based on: one or more MS relapseswithin the last 18 months prior to screening visit or radiological evidence of MSactivity (≥2 new T2 lesions within the last 12 months from screening [compared to aprevious recent MRI within 18 months of screening] or ≥1 GdE demonstrated on brainor spinal cord MRI performed within the last 12 months of screening).

5. Participants must be ambulatory with disease onset ≤ 5 years and treatment-naïve (i.e., no MS DMT at any time in the past).

6. Participants must be eligible to receive at least one form of DMT within eachtreatment arm.

7. EDSS at Baseline visit ≤ 6.5

Exclusion Criteria:

1. Participants with contraindications to all forms of DMT in either of the treatmentarms.

2. Participants must never have received any of the following medications: natalizumab,alemtuzumab, ocrelizumab, rituximab, ofatumumab, cladribine, siponimod, interferonbeta-1a, interferon beta-1b, pegylated interferon beta-1a, glatiramer acetate,fingolimod, teriflunomide, dimethyl fumarate, daclizumab, mitoxantrone, diroximelfumarate, ozanimod, monomethyl fumarate, ponesimod.

3. Participants must have not received any of the following medications, for reasonsother than MS, in the last 12 months: cyclophosphamide, azathioprine, mycophenolatemofetil, cyclosporine, methotrexate, leflunomide, laquinimod, atacicept, othermonoclonal antibodies.

4. Participants with clinically relevant medical or surgical conditions that, in theopinion of the investigator, would put the subject at risk by participating in thestudy

5. Participants unable to provide informed consent.

6. Contraindication or inability to undergo MRI with Gd due to metal or metal implants,allergy to Gd contrast, claustrophobia, pain, spasticity, or excessive movementrelated to tremor.

7. Unwillingness or inability to comply with the requirements of this protocolincluding the presence of any condition (physical, mental, or social) that, in theopinion of the PI, is likely to affect the participant's ability to comply with thestudy protocol.