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How does Ocrevus work for MS?

Medically reviewed by Carmen Pope, BPharm. Last updated on Aug 1, 2023.

Official answer


Ocrevus (ocrelizumab) works in multiple sclerosis (MS) by targeting a specific protein, called CD20 that exists on the surface of immature and mature B-lymphocytes. B lymphocytes are a type of white blood cell which are thought to contribute to the development of MS in several different ways, including secreting antibodies during an MS attack that cause inflammation which damages the myelin coating around nerve cells in the brain and spinal cord. When Ocrevus binds to this protein, it causes B-cells to self-destruct or disintegrate.

Ocrevus is a targeted treatment that is approved for the treatment of relapsing forms of multiple sclerosis (MS) and primary progressive MS in adults. It is a biological treatment called a monoclonal antibody.

How effective is Ocrevus in MS?

Research has shown that Ocrevus is effective at reducing the number of relapses per year in people with MS, increasing the percentage of people who remain relapse-free, and reducing the rate of disability progression. In one trial in people with early primary progressive MS, people taking Ocrevus were 24% less likely to have an increase in their disability than those taking placebo, which equates to delaying the need for a wheelchair by approximately seven years.

Ocrevus is given as an intravenous infusion every six months, after an initial dose of two infusions two weeks apart.

  • Ocrevus (ocrelizumab) 05/2020 Genentech, Inc.
  • Ocrevus. National Multiple Sclerosis Society. 2020,primary%20progressive%20MS%20in%20adults.
  • Lehmann-Horn K, Kronsbein HC, Weber MS. Targeting B cells in the treatment of multiple sclerosis: recent advances and remaining challenges. Ther Adv Neurol Disord. 2013;6(3):161-173. DOI:10.1177/1756285612474333

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