Friday, April 20 (HealthDay News) -- As part of a Phase 3 trial, Mark Freedman, M.D., from the University of Ottawa in Canada, and colleagues randomly assigned 517 individuals who had a first clinical demyelinating event and brain lesions detected by magnetic resonance imaging (MRI) to a subcutaneous serum-free formulation of IFN β-1a one or three times a week, or placebo. Placebo patients were switched to IFN β-1a three times a week after two years or after a diagnosis of clinically definite MS.
At three years, the researchers found that the probability of developing clinically definite MS was 41.3 percent for placebo patients switched to IFN β-1a, but was significantly lower for those who received IFN β-1a once a week (27.6 percent) or three times a week (27.1 percent). Similar results were found for the probability of a McDonald MS diagnosis, at 86.5, 79.1, and 66.8 percent, respectively.
"While doses three times a week and once a week equally delayed a clinically definite MS diagnosis without MRI measures, there were significantly more benefits in taking the drug three times a week compared with once a week when it came to brain lesion changes and other McDonald criteria for diagnosing MS," Freedman said in a statement.
The study was supported by Merck Serono S.A.