The goal of this clinical trial is to learn if drug CYB704, a proposed biosimilar to Ocrevus, works to treat multiple sclerosis in the same way as the reference product Ocrevus(R).

The main questions it aims to answer are:

• Is CYB704 distributed in the body in the same way as the reference product (demonstration of pharmacokinetic (PK) similarity)?
• Does have CYB704 the same treatment effect and side effects as the reference product?

Researchers will compare CYB704 to a Ocrevus (Ocrevus-US and Ocrevus-EU). Participants will:

• Take drug CYB704 or Ocrevus (Ocrevus-US and Ocrevus-EU)
• Visit the clinic for at least 15 treatment visits, checkups and tests
• Will undergo regular magnetic resonance imaging (MRI) examinations

Inclusion Criteria:

• Diagnosis of RMS (relapsing remitting multiple sclerosis (MS) or active secondary progressive MS)
• Evidence of recent disease activity as defined in study protocol
• Expanded Disability Status scale score of 0 to 5.5 (inclusive) at screening
• Neurological stability (no new signs or symptoms referable to Central Nervous System (CNS) within 30 days before both screening and first study treatment

Exclusion Criteria:

• Diagnosis of primary progressive MS
• Disease duration of more than 10 years in participants with an Expanded Disability Status Scale (EDSS) ≤2.0 at screening
• Inability to complete an MRI or contraindication to gadolinium administration
• History of allergic or anaphylactic reactions to ocrelizumab or one of the premedications (methylprednisolone or equivalent corticosteroid, antihistamine, antipyretic)
• Pregnant participants
• Current or history of medical conditions as outlined in the study protocol
• Prohibited medications (current and history) as outlined in the study protocol
• Abnormal laboratory blood values as outlined in the study protocol