Magnetic Resonance Imaging Effects of Interferon Beta-1b in the BENEFIT Study

Results: Data were analyzed from 248 patients taking interferon beta-1b and 156 taking placebo. Across 2 years the cumulative number of newly active lesions was lower in patients receiving interferon beta-1b vs placebo (median, 2.0 vs 5.0 [reduction of 60%]; P.001). This corresponded to lower cumulative numbers of new T2 lesions (median, 1.0 vs 3.0 [reduction of 66%]; P.001) and new gadolinium-enhancing lesions (median, 0.0 vs 1.0; P .001) in patients receiving interferon beta-1b vs placebo. From screening to month 24, T2 lesion volume decreased and was more pronounced in patients receiving interferon beta-1b (P=.02). Conclusions: Interferon beta-1b treatment had a robust effect on MRI measures, supporting its value as an early intervention in this patient group. This effect was maintained despite including patients who switched from placebo to interferon beta-1b in the active treatment group. Trial Registration: clinicaltrials.gov Identifier: NCT00185211