A comparison of the efficacy of interferon-β and glatiramer acetate in relapse-rate reduction: a prospective randomisation study

BACKGROUND: Interferon-β 1a (IM), interferon-β 1a (SC), interferon-β 1b, and glatiramer acetate are all used as first-line disease-modifying treatments (DMT) in relapsing-remitting multiple sclerosis. Each drug has proven efficacy in reducing relapse-rates. A small number of limited head-to-head comparisons have previously indicated little if any superiority of one agent over another. Therefore there remains a lack of objective long term evidence to support the choice of any one DMT over another in terms of efficacy. This is the first randomised study that the authors are aware of to compare the efficacy of relapse-rate reduction in all four DMTs. METHOD: Between 2002 and 2009, patients meeting the UK criteria to commence disease-modifying treatment were given the option to be entered into this trial and randomised to receive either interferon-β 1a (IM), interferon-β 1a (SC), interferon-β 1b, or glatiramer acetate. Their annual relapse rate (ARR) was retrospectively calculated for the two years prior to commencement of therapy and then an ARR was recorded every year at an annual review. Patients attended up to a maximum of 8 annual reviews where details of the number, duration, symptoms, and treatment of their relapses were recorded. Duration of treatment with the first DMT was also recorded to assess tolerability of the four drugs. RESULTS: 103 patients attended at least one annual review and were included in an intention-to-treat analysis (interferon 1a (IM), n = 28; interferon-β 1a (SC), n=27; interferon-β 1b, n=28; glatiramer acetate, n=20), with data collected from a total of 457 annual review years. All four DMTs showed a significant reduction in ARR. These reductions were in keeping with results from previous randomised trials. No significant difference in efficacy was found between the four DMTs (F=0.245, p=0.621). There was also no significant difference in tolerability between the four drugs as measured by time to first DMT cessation/change of drug (F= 0.740, p = 0.531). CONCLUSION: This randomised study provides further evidence of the efficacy of interferon-β 1a (IM), interferon-β 1a (SC), interferon-β 1b, and glatiramer acetate at reducing relapse-rates in patients with multiple sclerosis. In this head-to-head comparison of all four disease-modifying treatments, there was no significant difference in efficacy of relapse-rate reduction, or treatment tolerability.