A Powerful Treatment for a Severe Form of Multiple Sclerosis

Oocrelizumab (Ocrevus) is the first drug approved for the treatment of primary progressive multiple sclerosis.

Medically reviewed in April 2021

Updated on January 24, 2022

The drug ocrelizumab (Ocrevus) is approved by the U.S. Food and Drug Administration (FDA) to treat adults with severe forms of multiple sclerosis (MS), a disabling disease in which the immune system attacks the protective coating around the nerves.

Ocrelizumab was the first medication given the OK to treat primary progressive multiple sclerosis (PPMS), a rarer form of MS that makes up about 15 percent of diagnoses. People with PPMS experience progressively worsening neurological function from symptom onset, typically without remission or relapse. For people with relapsing forms of multiple sclerosis, ocrelizumab provides another treatment option.

A treatment offers some hope
"We've been banging on a wall with a bunch of drugs, and we finally put a big crack in the wall," Jerry Wolinsky, MD, professor emeritus at the University of Texas Health Science Center at Houston, told CNN in March 2017, when the drug was approved. Dr. Wolinsky was a lead author on the 2017 study published in New England Journal of Medicine that showed that ocrelizumab slowed the progression of PPMS.

Ocrelizumab is administered through an intravenous infusion every six months. The drug blocks B cells, immune system cells that play a big part in the condition. This differs from other MS drugs on the market, which target T cells, thought to be another critical contributor to MS.

For the treatment of PPMS, ocrelizumab was tested in 732 people for at least 120 weeks. People who received ocrelizumab were slower to decline into worsening disability when compared to placebo. For the treatment of relapsing forms of MS, ocrelizumab was tested in two clinical trials, which were also published in 2017 in New England Journal of Medicine. A total number of 1,656 people were treated with either ocrelizumab or another MS drug, called Rebif, for 96 weeks. In both trials, ocrelizumab reduced both relapse rates and progression of disability when compared to Rebif.

Some side effects related to infusion administration include itchy skin, rash, or redness. Upper respiratory infection was another reported side effect. There were additional serious side effects associated with the drug. For example, it could lead to an increased risk of cancer or cause hepatitis B to reactivate in people who have the infection.

Multiple sclerosis, explained
MS is a devastating autoimmune disease affecting about 2.3 million people worldwide. It occurs when the immune system attacks the protective coating, called myelin, that surrounds the nerve fibers in the brain and spinal cord. Damage to myelin causes communication problems between the brain and the body. Over time, as the disease progresses, the nerves can deteriorate or become permanently damaged. Typical MS symptoms include fatigue, difficulty walking, involuntary muscle spasms or spasticity, cognitive impairment, depression, and vision problems.

While the cause of MS is unknown, there are some factors that may increase your risk. MS most commonly affects people between ages 20 and 40. Women are also more likely to develop the disease. If you have a parent or sibling with MS, you might also be at increased risk.

For people with PPMS who tend to experience severe neurological impairment without remission, ocrelizumab may provide much-needed relief.

Article sources open article sources

U.S. Food and Drug Administration. FDA approves new drug to treat multiple sclerosis. March 29, 2017.
Montalban X, Hauser SL, Kappos L, et al. Ocrelizumab versus Placebo in Primary Progressive Multiple Sclerosis. N Engl J Med. 2017;376(3):209-220.
Hauser SL, Bar-Or A, Comi G, et al. Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis. N Engl J Med. 2017;376(3):221-234.
Michael Nedelman. CNN Health. FDA approves first treatment for severe type of multiple sclerosis. March 29, 2017.

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