Weekly IM interferon beta-1a in multiple sclerosis patients over 50 years of age

Abstract

Background: Efficacy and safety data have not previously been compiled for intramuscular interferon beta-1a (IM IFNβ-1a) in patients with multiple sclerosis (MS) ≥50years of age. We investigated the efficacy and safety of IM IFNβ-1a in patients segregated by 50 and 40years of age in separate meta-analyses. Methods: The MS Clinical Research Group Study, the Controlled High-Risk Subjects AVONEX ® (IM IFNβ-1a) MS Prevention Study, the IFNβ-1a European Dose-Comparison Study, and a multicenter, open-label antigenicity and safety study of human serum albumin-free IM IFNβ-1a were analyzed. Results: Overall, 906 patients (68 aged ≥50years and 838 aged <50years, or 323 aged ≥40years and 583 aged <40years) received IM IFNβ-1a for ≥24months. At baseline, patients ≥50years had significantly higher Expanded Disability Status Scale scores than patients <50years (3.4 vs. 2.8; P<0.001), but fewer relapses in the three preceding years (2.6 vs. 3.4; P<0.001); patients ≥40years and <40years exhibited similar differences. After 2years of treatment, there were no significant differences in annualized relapse rate, sustained disability progression, time to sustained disability progression, or number of MRI-identified gadolinium-enhanced lesions between age groups in either analysis. The cumulative probability of relapse was significantly lower in patients ≥40years versus patients <40years (0.601 vs. 0.702; P<0.001). Adverse event incidence did not differ significantly between age groups in either analysis. Conclusions: IM IFNβ-1a is effective and well tolerated in patients with MS ≥40 and ≥50years as well as younger patients. © 2011 The Author(s). European Journal of Neurology © 2011 EFNS.