• Diagnosis of RMS (2017 Revised McDonald criteria).

• Participants must meet one of the following prior treatment definitions:

‣ Participants naïve to treatment.

⁃ Participants previously treated with a disease modifying therapy (DMT) who have discontinued treatment prior to consent and meet the washout requirements.

• Expanded Disability Status Scale (EDSS) score ≤ 5.5 at screening.

• Neurologically stable for \> 30 days prior to first dose of ublituximab.

• Female participants of childbearing potential must consent to use a medically acceptable method of contraception from consent, throughout the study period, and for 6 months after the last dose of ublituximab.