A team led by researchers from the Cleveland Clinic's Neurological Institute reports that a promising drug slowed brain shrinkage in progressive multiple sclerosis (MS) by nearly half. Limited therapies are currently available for this disabling form of the disease, according to the scientists.
The definitive results of the Phase II trial (“Phase 2 Trial of Ibudilast in Progressive Multiple Sclerosis”), published in the New England Journal of Medicine, showed that the drug ibudilast decreased progression of brain atrophy in progressive MS patients by 48% versus placebo. The two-year SPRINT-MS study was conducted at 28 sites with 255 patients.
“These findings are significant for patients with progressive MS,” says Robert Fox, M.D., the study's principal investigator and vice-chair for research at the Cleveland Clinic's Neurological Institute. “Our hope is that the benefit of ibudilast in slowing brain shrinkage will also translate to decreased progression of associated physical disabilities in a future Phase III trial.”
Progressive MS is associated with gradual worsening of symptoms and increasing disability. It commonly follows relapsing-remitting MS, for which there are more than a dozen approved treatments. However, none of these therapies has consistently demonstrated efficacy in slowing disability progression in patients with progressive MS, particularly those without evidence for active inflammation.
Ibudilast, an oral drug with activity on several biologic pathways with potential relevance to progressive MS, was approved in Japan in 1989 for use in asthma and stroke. It is also being studied in the U.S. for potential treatment of amyotrophic lateral sclerosis (ALS) and drug addiction.
Additionally, the SPRINT-MS study demonstrated the utility of advanced imaging in clinical trials to measure the impact of therapies on brain health. The potential application of imaging-based outcome measures may extend beyond progressive MS to other neurodegenerative disorders as well.
“There is a significant need for new treatment options to effectively delay disability progression for patients with progressive MS,” says Dr. Fox. “We are hopeful these findings will help us develop more therapies for progressive MS, and do so more rapidly and efficiently.”
“Although a larger study is needed to confirm these findings, this promising study brings people with progressive MS, who currently do not have many treatment options, one step closer to a potential therapy,” says Robin Conwit, M.D., program director at the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health.
“These results are a promising step toward a potential new therapy for people living with progressive forms of MS, for whom there are few treatment options,” says Bruce Bebo, Ph.D., executive vice president, research, National MS Society. “It is gratifying to see our investments in progressive MS starting to pay off.”