INTERFERON BETA-1B IS EFFECTIVE IN RELAPSING-REMITTING MULTIPLE-SCLEROSIS .2. MRI ANALYSIS RESULTS OF A MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL

We performed yearly MRI analyses on 327 of the total 372 patients in a multicenter, randomized, double-blind, placebo-controlled trial of in terferon beta-1b (IFNB). Clinical results are presented in the precedi ng companion paper. Baseline MRI characteristics were the same in all treatment groups. Fifty-two patients at one center formed a cohort for frequent MRIs (one every 6 weeks) for analysis of disease activity. T he MRI results support the clinical results in showing a significant r eduction in disease activity as measured by numbers of active scans (m edian 80% reduction, p = 0.0082) and appearance of new lesions. In add ition, there was an equally significant reduction in MRI-detected burd en of disease in the treatment as compared with placebo groups (mean g roup difference of 23%, p = 0.001). These results demonstrate that IFN B has made a significant impact on the natural history of MS in these patients.