SPRINT-MS was a phase II study designed to assess the effectiveness and safety of ibudilast (MN-166) in people with progressive MS. 255 people with secondary and primary progressive MS took either ibudilast or placebo as tablets daily for nearly two years. MRI was used to measure brain volume at the beginning and end of the study. Compared to placebo, ibudilast slowed down the loss of brain volume (brain atrophy) by 48%. Although the study wasn't looking at any effect on MS symptoms or the rate of progression, loss of brain volume is linked to cognitive and physical disability in MS and is used as a marker for MS progression.
Ibudilast was generally well-tolerated. The most common side effects associated with ibudilast included gastrointestinal problems such as nausea, diarrhoea and abdominal pain, as well as depression and headache.
What next for ibudilast?
While these promising results indicate that ibudilast may slow down progression in MS, the drug will need to be tested in larger phase III clinical studies using more direct measures of disability such as mobility, hand/arm function and cognition.
More about ibudilast
Ibudilast is used in Japan and Korea to treat asthma and some complications of stroke. It acts on a number of cell processes associated with nerve damage and myelin repair. Previous studies have suggested it may have a neuroprotective effect.