A study published in the journal The Lancet announced the results of the Phase 2 study for ocrelizumab. The researchers found that ocrelizumab led to an 89 percent decrease in the formation of brain lesions and reduction of flare ups or attacks that characterize the disease.
"Ocrelizumab is one step closer to being available for MS patients."
MS is an autoimmune disease that attacks myelin, neurons' protective coating in the brain and spinal cord. Damage to these myelin sheaths causes the brain lesions, or abnormal areas of tissue, that characterize the disease. Ultimately, the attacks lead to the dehibilatating symptoms such as vision impairment, loss of balance, and muscle spasms.
Most treatments for MS target T cells in the immune system, which attack the nerve fibers in the brain. Ocrelizumab has a different target. It takes aim at a molecule called CD20, which sits on the surface of immune cells called B cells.
Scientists believe that the B cells are what cause the T cells to attack. The idea behind ocrelizumab is that if you stop the B cells from firing their instructions to the T cells, the T cells will not be attack the immune system's myelin.
The clinical trial involved 220 MS patients in hospitals in the United States, Canada, and Europe. The patients all had relapse-remitting MS, the most common form of the disease. They were divided up into four groups: Two received the trial drug at different doses, one received a standard treatment, and one took a placebo.
The doctors compared the effectiveness of each treatment using MRIs, counting lesions, and the severity and frequency of attacks. The patients who took ocrelizumab generally fared better than patients in the other groups. They had fewer signs of the disease, and reduction in the number of brain lesions and attacks over the course of 24 weeks.
The next step is a Phase 3 clinical trial, using a larger number patients who will receive the drug for a longer period of time. This trial is now underway.
The study was sponsored by Roche, the company which owns ocrelizumab.