(HealthDay News) – Individuals suspected of having multiple sclerosis (MS) are less likely to be diagnosed with clinically definite disease if they soon start treatment with interferon (IFN) β-1a, according to a study presented at the annual meeting of the American Academy of Neurology, held from April 21–28 in New Orleans.
As part of a Phase 3 trial, Mark Freedman, MD, 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% for placebo patients switched to IFN β-1a, but was significantly lower for those who received IFN β-1a once a week (27.6%) or three times a week (27.1%). Similar results were found for the probability of a McDonald MS diagnosis, at 86.5%, 79.1%, and 66.8%, 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.