In October, the FDA approved interferon beta-1b (Betaseron) for patients who have a first clinical episode and MRI features that are consistent with multiple sclerosis (MS), making it the only drug indicated for early MS. Previously, the drug had been approved only for relapsing MS.
The agency's decision was based on a study, published in the October 10 issue of Neurology (67:1242–1249), that included patients with a first clinical demyelinating event and at least two clinically silent brain MRI lesions. Of these patients, 292 received interferon beta 1-b every other day and 172 were given placebo. After two years, 45 percent of the placebo group and 28 percent of the treated group had a second MS attack, a significant difference (p < 0.0001). The study was sponsored by the drug's marketer, Schering AG of Germany.
“The evidence is strong that the earlier interferon beta-1b is used, the more effective it is,” said George H. Kraft, MD, Alvord Professor of MS Research at the University of Washington in Seattle. Dr. Kraft, who was not affiliated with the study, added that he was not surprised with the findings because another version of the drug, a low-dose interferon beta-1b (Avonex), demonstrated a similar level of effectiveness in early MS (Ann Neurol 2002;51:481-190).