Combination therapy shows promise for relapsing MS
medwireNews: Combining the two most common therapies for relapsing-remitting multiple sclerosis (RRMS) provides improved reduction of new lesion activity and accumulation of total lesion over either single-agents, show findings from a randomized, placebo-controlled trial.
Although the combination of interferon β-1a (IFN) and glatiramer acetate (GA) did not produce a significant clinical benefit among patients, it was superior to both IFN and GA in reducing disease activity, report Fred Lublin (Corinne Goldsmith Dickinson Center for Multiple Sclerosis, New York, USA) and team.
The CombiRx trial was a multicenter study including 1008 patients with RRMS who were randomly allocated to receive a combination of IFN 30 µg weekly plus GA 20 mg daily or one of the single agents plus matching placebo. Patients were followed up for 36 months.
As reported in the Annals of Neurology, both the combination therapy and GA were significantly better at improving the annual relapse rate (ARR; as defined by the incidence of protocol-defined exacerbation) than IFN, after adjustment for confounders. The ARR did not significantly differ between those on combination therapy and those on GA.
There was no significant difference between the groups in the proportion of patients with 6-month progression of the Expanded Disability Status Scale or in scores for the Multiple Sclerosis Functional Composite Scale.
All three treatments were effective at reducing the number of enhanced lesions, as measured by magnetic resonance imaging (MRI), within 6 months of treatment initiation. However, at 36 months the combination of IFN and GA was superior to either IFN or GA monotherapy in reducing lesion enhancement, after adjustment for age and the number of enhancements at baseline.
The cumulative number of enhancements showed similar results, with 89.8% of those on IFN plus GA free of enhancements, compared with 84.8% of those on IFN, and 84.5% of those on GA.
A post-hoc analysis of disease activity-free status (DAFS, with no clinical activity or combined unique activity), showed that there was a significant effect of the combination therapy over both IFN and GA.
"The core MRI results show very interesting patterns of potential benefit for the combination compared to the single-agent groups in reducing lesion load and activity," say Lublin et al.
"We will look to see whether this effect produces a corresponding clinical effect in the extension portion of this study with subjects followed well beyond three years," they add.
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By Sally Robertson, medwireNews Reporter