Living with multiple sclerosis (MS) can be unpredictable and exhausting, from fatigue and muscle weakness to sudden changes in mobility or vision. Modern medicine, however, continues to bring new hope. One such advancement is Ocrelizumab (brand name: Ocrevus), a prescription medication designed to slow down the progression of MS and help patients maintain independence and quality of life.

Ocrelizumab is a monoclonal antibody therapy that targets specific immune cells involved in damaging the nervous system. Approved by the U.S. Food and Drug Administration (FDA) in 2017, it is considered one of the first therapies effective for both relapsing forms of MS (RMS) and primary progressive MS (PPMS) making it a significant milestone in MS care.

What does Ocrelizumab do?

Ocrelizumab is prescribed for adults with:

• Relapsing forms of multiple sclerosis (RMS), including relapsing-remitting disease and active secondary progressive disease.
  
  
• Primary progressive multiple sclerosis (PPMS), a form that causes gradual worsening of symptoms without distinct relapses.

For many patients, Ocrelizumab helps:

• Reduce relapse frequency in relapsing MS.
  
  
• Slow disability progression in both relapsing and primary progressive forms.
  
  
• Decrease MRI-detected brain lesions, which are markers of nerve damage.

Clinical studies have shown that patients taking Ocrelizumab experienced fewer relapses and less disability progression compared to those treated with interferon-based medications (Hauser et al., 2017). These improvements often translate to a better quality of life and longer periods of functional stability.

How does Ocrelizumab work?

Ocrelizumab works by targeting CD20-positive B cells, a specific type of immune cell that plays a role in attacking the myelin sheath (the protective covering of nerves) in people with MS. By binding to these cells, Ocrelizumab reduces abnormal immune activity while preserving the rest of the immune system’s ability to fight infections.

In simpler terms, this treatment “calms down” the immune system just enough to prevent it from damaging the brain and spinal cord without shutting it down completely.

Clinically, this mechanism helps:

• Reduce new inflammatory lesions in the nervous system.
• Protect nerve fibers from further degeneration.
• Potentially delay long-term physical disability.

This targeted approach distinguishes Ocrelizumab from older MS treatments that act broadly on the immune system, leading to more side effects or reduced immunity.

Ocrelizumab side effects

Like all medications, Ocrelizumab can cause side effects, though many are manageable under medical supervision.

Common side effects include:

• Infusion-related reactions (itching, rash, throat irritation, flushing or low blood pressure during or after infusion)
• Fatigue
• Upper respiratory tract infections
• Headache

Less common but potentially serious side effects:

• Increased risk of infections, including herpes or respiratory infections
• Reactivation of hepatitis B virus (in patients with prior infection)
• Rare cases of progressive multifocal leukoencephalopathy (PML), a severe brain infection

Who should avoid or use caution:

• People with active infections should postpone treatment until fully recovered.
• Those with a history of hepatitis B require screening and close monitoring.
• Patients with weakened immune systems should discuss risks thoroughly with their healthcare provider.

Seek immediate medical attention if you have trouble breathing, severe rash, chest pain or signs of an allergic reaction during infusion.

While these risks sound concerning, most patients tolerate Ocrelizumab well when infusion safety protocols and monitoring guidelines are followed.

Ocrelizumab dosage

Ocrelizumab is administered as an intravenous (IV) infusion by a healthcare professional. The first dose is split into two infusions two weeks apart, followed by one infusion every six months.

Before each infusion, patients are often given medications like antihistamines or corticosteroids to minimize infusion-related reactions.

Monitoring during treatment typically includes:

• Regular blood tests to check immune cell levels and liver function.
• MRI scans to track disease activity and lesion development.
• Screening for infections such as hepatitis B prior to starting therapy.

Special attention is given to older adults and those with weakened immunity, as they may be more susceptible to infections. Consistent follow-up helps ensure that the benefits of Ocrelizumab outweigh potential risks.

Does Ocrelizumab have a generic version?

As of now, no generic version of Ocrelizumab is available. It is marketed exclusively under the brand name Ocrevus by Genentech (a subsidiary of Roche).

While biosimilar versions may eventually become available, they must first undergo FDA evaluation to confirm they match the original in safety, purity, and potency.

Patients should be aware that FDA-approved biosimilars, once released, will be just as effective and safe as the brand-name drug but typically more affordable.

Conclusion

Ocrelizumab represents a major advancement in the treatment of multiple sclerosis—offering hope to those living with both relapsing and progressive forms of the disease. By selectively targeting harmful immune cells, it helps slow disease progression and protect neurological function.

While side effects and infusion reactions can occur, the overall safety and efficacy profile of Ocrelizumab make it a trusted option under the care of a qualified neurologist.

Every patient’s experience with MS and its treatment is unique. Staying informed, attending regular checkups, and discussing any new symptoms with your doctor can help you get the most out of your therapy.

Ocrelizumab is most effective when prescribed, monitored and supported by an experienced healthcare team, empowering patients to live with greater stability, control and confidence.

References

1. Hauser, S. L., et al. (2017). Ocrelizumab in relapsing multiple sclerosis. New England Journal of Medicine, 376(3), 221–234. https://www.nejm.org/
2. U.S. Food and Drug Administration (FDA). (2017). FDA approves new drug to treat multiple sclerosis. https://www.fda.gov/
3. Mayo Clinic. (2024). Ocrelizumab (Intravenous Route) Description and Precautions. https://www.mayoclinic.org/