A randomized study of two interferon- beta treatments in relapsing–remitting multiple sclerosis

Abstract

Objective: To investigate whether the efficacy of interferon-beta (IFNβ) treatment of relapsing–remitting MS (RR-MS) was influenced by type, dose, and frequency of administration.Methods: From June 1996 through October 1997, the authors offered participation to all Danish RR-MS patients who met the following criteria: definite MS, at least two relapses within 2 years, age 18 to 55, and an Expanded Disability Status Scale (EDSS) score of ≤5.5. The study was multicenter, controlled, open-label, randomized, head-to-head comparing IFNβ-1a 22 μg once a week (n = 143) with IFNβ-1b 250 μg every other day (n = 158), both subcutaneously, for 24 months. Patients who declined randomization were offered treatment with IFNβ-1b 250 μg every other day (n = 120). The primary end-points were the annualized relapse rate, the time to first relapse, and neutralizing antibody formation. The secondary endpoint was time to sustained progressionResults: The annual relapse rates were virtually equal in the two arms of the randomized study (IFNβ-1a: 0.70; IFNβ-1b: 0.71); so were the time to first relapse and the time to sustained progression. In the nonrandomized patients (IFNβ-1b), the annual relapse rate was not significantly different, but the time to progression was shorter.Conclusion: In this study, 250 μg interferon-beta-1b administered every other day did not prove clinically superior to once-a-week administration of 22 μg interferon-beta-1a.