R R

What Is Ocrelizumab?

Ocrelizumab is a prescription monoclonal antibody that targets CD20-positive B cells involved in multiple sclerosis (MS). It is the active ingredient in Ocrevus, an intravenous medication used for certain relapsing forms of MS and primary progressive MS. The intravenous formulation is also approved for relapsing-remitting MS in certain pediatric patients. Ocrelizumab is additionally available with hyaluronidase in a separate subcutaneous product called Ocrevus Zunovo. It modifies immune activity to reduce disease activity but does not cure MS.

Link to This Resource Page

Provide a valuable resource to your clients or customers by linking to this resource page. Just place the following link on your website.

To display this...

What Is Ocrelizumab?

Ocrelizumab is a prescription monoclonal antibody that targets CD20-positive B cells involved in multiple sclerosis (MS). It is the active ingredient in Ocrevus, an intravenous medication used for certain relapsing forms of MS and primary progressive MS. The intravenous formulation is also approved for relapsing-remitting MS in certain pediatric patients. Ocrelizumab is additionally available with hyaluronidase in a separate subcutaneous product called Ocrevus Zunovo. It modifies immune activity to reduce disease activity but does not cure MS.

read more about ocrelizumab ...

Copy this HTML:

Copy HTML Copied!

How Does Ocrelizumab Work?

Ocrelizumab binds to CD20, a protein found on the surface of certain B lymphocytes. These immune cells participate in inflammatory processes that contribute to damage within the central nervous system in multiple sclerosis. Binding to CD20 causes the targeted B cells to be depleted through immune-mediated mechanisms. This can reduce inflammatory disease activity and slow certain measures of disability progression. The medication does not directly repair existing nerve damage or restore lost myelin.

What Conditions Does Ocrelizumab Treat?

Intravenous ocrelizumab is approved for relapsing forms of multiple sclerosis in adults, including clinically isolated syndrome, relapsing-remitting MS, and active secondary progressive MS. It is also approved for primary progressive MS in adults. Under updated U.S. labeling, intravenous Ocrevus treats relapsing-remitting MS in children aged 10 years and older who weigh at least 25 kilograms. The separate subcutaneous Ocrevus Zunovo product is approved for specified adult forms of MS. Treatment selection depends on disease type, age, weight, infection history, and clinical assessment.

How Is Ocrelizumab Administered?

Intravenous ocrelizumab is administered by healthcare professionals. Adult treatment commonly begins with two 300 mg infusions given two weeks apart, followed by 600 mg every six months. Pediatric dosing for the approved population follows weight-based instructions. Ocrevus Zunovo has a different subcutaneous dosing schedule and must not be administered using intravenous instructions. Before treatment, clinicians screen for hepatitis B and assess immunoglobulin levels and liver function. Premedication and observation help manage administration reactions.

What Are the Side Effects and Warnings of Ocrelizumab?

Common adverse effects include respiratory infections and infusion-related or injection-related reactions, depending on the formulation. Serious risks include hepatitis B reactivation, severe infections, reduced immunoglobulin levels, and progressive multifocal leukoencephalopathy, a rare brain infection. Liver injury and immune-mediated colitis have also been reported. Vaccination status should be reviewed before treatment, and live vaccines are generally avoided during B-cell depletion. Patients should promptly report persistent infections, unusual neurological symptoms, severe diarrhea, or signs of liver problems.

Common Questions About Ocrelizumab

Is ocrelizumab the same as Ocrevus?

Yes. Ocrelizumab is the active ingredient in Ocrevus. Ocrevus Zunovo contains ocrelizumab combined with hyaluronidase and has different administration instructions.

Can ocrelizumab treat progressive multiple sclerosis?

Yes. Intravenous ocrelizumab is approved for primary progressive multiple sclerosis in adults, as well as certain relapsing forms of MS.

How often is ocrelizumab administered?

Adult intravenous treatment generally starts with two infusions separated by two weeks, followed by maintenance infusions every six months. Other formulations and pediatric regimens follow different instructions.

Does ocrelizumab weaken the immune system?

Ocrelizumab reduces certain B cells and can increase susceptibility to infections. Clinicians assess infection risks and monitor patients during treatment.

References

DailyMed - OCREVUS (ocrelizumab) injection. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9da42362-3bb5-4b83-b4bb-b59fd4e55f0d. Date Accessed October 22, 2026.

Ocrelizumab. LiverTox. https://www.ncbi.nlm.nih.gov/books/NBK548145/. Date Accessed October 22, 2026.

Ocrelizumab. PubChem. https://pubchem.ncbi.nlm.nih.gov/compound/Ocrelizumab. Date Accessed October 22, 2026.

Ocrelizumab Injection. MedlinePlus. https://medlineplus.gov/druginfo/meds/a617026.html. Date Accessed October 22, 2026.

Ocrevus. European Medicines Agency. https://www.ema.europa.eu/en/medicines/human/EPAR/ocrevus. Date Accessed October 22, 2026.