Key Inclusion Criteria:  Participants eligible for inclusion in this study must meet all of the following criteria:  Signed informed consent must be obtained prior to participation in the study  Age 18-35 years  Patients in the healthy control arm eligible for inclusion must fulfill the following criteria:  Able to obtain MRI (HC with abnormal MRI at Screening will be excluded) and use wearable device  Able to provide blood sample (no CSF will be collected in HC)  Patients in the ofatumumab-treated arm eligible for inclusion must fulfill the following criteria:  Diagnosis of RRMS per McDonald Criteria (2010/2017) Within 6 months of diagnosis of clinically definite MS (CDMS) EDSS 0-3.0 (Inclusive) Treatment-naïve to MS DMT Able to obtain MRI and attend study visits at sites Able to use wearable device Able to provide blood sample (and CSF for sub-group n=15)  Key Exclusion Criteria:  Participants in the healthy control arm meeting any of the following criteria are not eligible for inclusion in this study:  Confounding medical condition as determined by the investigator  RRMS patients fulfilling any of the following exclusion criteria are not eligible for inclusion in this study:  Diseases other than multiple sclerosis responsible for the clinical or MRI presentation Patients with neuromyelitis optica, Radiologic/ Clinically Isolated Syndrome, Secondary Progressive or Primary Progressive MS diagnosis Use of experimental or investigational drugs for MS Previous use of Disease Modifying Therapy (DMT) or chemotherapeutic medications for MS Relapse between screening and Baseline visits Known sensitivity to gadolinium; patients with chronic, severe kidney disease Known history of hypersensitivity to any of the study treatments or its excipients or to drugs of similar chemical classes CNS anomalies that are better accounted for by another disease process or MRI anomalies causing clinically apparent impairments Known active malignancies Pregnant or nursing (lactating) women Females of childbearing potential (all women physiologically capable of becoming pregnant) should use effective contraception while receiving ofatumumab and for 6 months after the last treatment of ofatumumab Patients with an active chronic disease (or stable but treated with immune therapy) of the immune system other than MS or with immunodeficiency syndrome Patients with active infections including systemic bacterial, viral (including SARS-CoV-2/COVID-19) or fungal infections, or known to have AIDS or to test positive for HIV antibody at Screening Patients with neurological findings consistent with Progressive Multifocal Leukoencephalopathy (PML), or confirmed PML Patients with IgG or IgM levels below LLN at Screening Patients that have received any live or live-attenuated vaccines within 4 weeks prior to first dose of study drug administration Patients at risk of developing or having reactivation of hepatitis