A drug called ocrelizumab has had some success in separate clinical trials. It was able to decrease new attacks in patients with relapsing remitting multiple sclerosis (MS), and in patients with primary progressive MS, the drug halted the progression of new symptoms. The research was conducted by an international team of researchers in three studies, which included Amit Bar-Or and Douglas Arnold of the Montreal Neurological Institute and Hospital of McGill University. The following is an interview with Dr Amit Bar-Or by The International Progressive MS Alliance interviews, from last year.
Multiple sclerosis is a disease of the central nervous system that usually gradually gets worse over time. The cause is still mysterious, and the symptoms can vary widely in affected individuals. In MS, the immune system attacks a part of the nervous system called myelin, a sort of insulation for nerve cells.
One study, reported in the New England Journal of Medicine, involved 732 patients afflicted by primary progressive MS who received one of three randomized treatment assignments: a placebo, the ocrelizumab drug, or a humanized monoclonal antibody that depletes a type of cell called CD20+ B. The research team confirmed that ocrelizumab had a significant impact on new attacks in patients with relapsing MS, as well as slow the progression of symptoms caused by primary progressive MS. At twelve weeks, patients on the ocrelizumab had a 32.9 percent disability progression compared to 39.3 percent on placebo. At 24 weeks, the placebo showed a disability progression of 35.7 percent compared to 29.6 for those taking ocrelizumab. And by week 120, patients who took a timed 25-foot walk had worsened by 55.1 per cent in patients taking a placebo compared to a 38.9 percent worsening for patients receiving ocrelizumab.
There was also a reduction in other symptoms; there was a reduction in brain volume and fewer brain lesions in patients given the ocrelizumab treatment.
In other studies involving patients with relapsing remitting MS, it was found that the rate of disease relapse was reduced in patients given ocrelizuma by 46 percent in one study and by 47 percent in the other. Ocrelizuma also reduced new brain lesions in these patients and lessened the risk of disability progression.
"The results in patients with relapsing remitting MS not only demonstrate very high efficacy against relapses, but also underscore the important emerging role of B cells of the immune system in the development of relapses," explained Bar-Or. "While the results in patients with primary progressive MS are more modest, they nonetheless represent the very first successful trial in such patients, a breakthrough as primary progressive MS now transitions from a previously untreatable condition to one that can be impacted by therapy. It is an important step forward in the field,” he concluded.