For the very first time, news has been announced of a drug which may be able to slow the advancement of primary progressive MS.
Ocrelizumab is an intravenous infusion taken every six months, and results are showing that it reduces the immune response by targeting a type of immune cell (the B cell) which attacks and consequently damages myelin. The phase 3 clinical trials of Ocrelizumab for both relapsing-remitting MS and primary progressive MS, completed in June 2015, were published in the New England Journal of Medicine on December 22, 2016. The trials in relation to RRMS involved over 1600 people, and reported that the drug reduced the annual relapse rate by 46% in the first trial; by 47% in the second; and reduced the progression of clinical disability by 40%.
Furthermore, Ocrelizumab was shown to reduce the number of lesions in the brain by 94%, compared with a placebo. The trial regarding PPMS involved 732 people with the condition who received two infusions, 14 days apart, in each treatment cycle. Results showed that the percentage of people with disability progression dropped from 39% without treatment, to 33% on Ocrelizumab. Those who took the drug performed better on a test recording the time taken to walk 25 feet, and MRI results showed a reduction in the rate of brain atrophy. No unexpected adverse side effects were reported during the trials, although longer term studies are necessary to ascertain the drug’s full safety profile.
A licensing application has been submitted by Ocrelizumab’s developers, Hoffmann-La Roche, and accepted by the European Medicines Agency who are currently reviewing the data, and from whom a decision is expected to be announced late in 2017. Speaking to a health and science reporter for the BBC news website, Prof Gavin Giovannoni, from Barts and The London School of Medicine and Dentistry said:
"The results shown by these studies have the potential to change how we approach treating both relapsing and primary progressive MS. It’s very significant because this is the first time a phase three trial has been positive in primary progressive MS."
While the results were positive for people with PPMS, the drug made only a small difference to the proportion of people whose disability progressed. The MS community still awaits a therapy that can substantially change the course of primary progressive disease.