People with multiple sclerosis (MS) who were treated with combination therapy did not see significant clinical benefit over those treated with single drug therapy, but combination therapy did reduce the development of new lesions, according to an international research team led by The Mount Sinai Medical Center. The findings, part of the largest-ever MS trial sponsored by the National Institutes of Health, are published in the March 11 issue of Annals of Neurology.
In the Phase III CombiRx trial, researchers led by Fred Lublin, MD, of The Mount Sinai Medical Center, sought to determine if Glatiramer Acetate (GA) and Interferon Beta-1a (IFN), the two most commonly-prescribed drugs for relapsing-remitting MS (RRMS), were more effective in combination than as monotherapies. The results showed that while combination therapy was no better than monotherapy, patients who took combination therapy had a reduction in new lesions on MRI scan.
"This is the first NIH-sponsored, multi-center, comparative trial evaluating the benefits of both combination therapy and monotherapy in MS," said lead author Fred Lublin, MD, Director of the Corinne Goldsmith Dickinson Center for Multiple Sclerosis at The Mount Sinai Medical Center. "The study is the first to show that a combination trial is feasible in MS, to compare a combination to established monotherapy, and to provide comparative efficacy data for two commonly-prescribed drugs."
The research team enrolled 1,008 participants from 68 sites to receive IFN plus GA (499), IFN alone (250), or GA alone (259), with 30-g IFN administered intramuscularly weekly and/or 20 mg of GA injected daily. The groups were followed for three years to assess if the combination therapy reduced MS relapse rates.
While combining IFN and GA was safe and effective, patients taking this regimen did not see clinical benefit greater than those taking a single agent. There was no substantial improvement in neurological function in participants in the combination therapy group. They also found that GA alone was superior to IFN alone in reducing relapse rates. MRI findings also suggested that the IFN plus GA together were better in reducing new lesions and total lesion accumulation than either drug alone.