A Study to Evaluate Pharmacokinetics (PK) and Safety of Subcutaneous (SC) Ublituximab Administered at Various Injection Sites and Relative Bioavailability Via Autoinjector (AI) Versus Syringe Subcutaneously in Participants With Multiple Sclerosis (MS)

Prior treatment

• Participants who received any approved therapy to treat MS within 5 half-lives of the medication prior to screening.
• Treatment with any investigational agent within 5 half-lives of the investigational drug prior to screening.

Other illness

• Active chronic disease of the immune system other than MS or immunodeficiency syndrome.

Other

• Primary-progressive multiple sclerosis (PPMS) or inactive secondary progressive multiple sclerosis (SPMS).
• Participants with significantly impaired bone marrow function or significant leukopenia or thrombocytopenia.
• Females who are pregnant or nursing.
  • Note: Other protocol-specified Inclusion/Exclusion criteria may apply.

• Diagnosis of relapsing multiple sclerosis (RMS) (2017 Revised McDonald criteria).
• Expanded Disability Status Scale (EDSS) score less than or equal to (≤) 5.5 at screening.
• Neurologically stable for more than (\>) 30 days prior to screening and Day 1.
• Female participants of childbearing potential must consent to use an effective method of contraception from consent and for 6 months after the last dose of ublituximab.