Ibudilast Phase 2 Trial Results for Progressive MS

Research Summary: Phase 2 Trial of Ibudilast in Progressive Multiple Sclerosis

What is it?

Ibudilast is an anti-inflammatory treatment, which also has effects that protect nerves.  It is thought to offer this protection in a few different ways, one of which is by decreasing the amount of reactive oxygen species that are formed.  Reactive oxygen species are known to cause damage to nerves through a process called oxidative stress.

What was the trial?

Ibudilast has completed a Phase 2 trial for the treatment of progressive multiple sclerosis.  The trial involved a number of different sites across the United States and took place across 96 weeks.  There were 255 people in the study, who were randomly assigned to receive either ibudilast or placebo.  Both groups included approximately 50% people with primary progressive MS (PPMS) and 50% with secondary progressive MS (SPMS).  The results have been published in the New England Journal of Medicine and the abstract can be found here.

What did it show?

The main outcome was that people receiving ibudilast had less brain atrophy (that is, the rate of brain loss was slower) than those who were on placebo.  There were no major safety concerns observed in the people that took the treatment.  However, as with all treatments, there were some side-effects observed – the most commonly reported were gastrointestinal issues, headaches and depression.

What are the next steps?

This trial wasn’t designed to work out what the clinical impact of the treatment was.  This means that, while it has shown that ibudilast can slow the rate of brain tissue loss in people with progressive MS, it isn’t clear what (if any) effect that has on their symptoms.  Further testing in larger studies will be required to answer this question.  As there are few treatment options available for people with progressive MS, any new therapy that shows promise should be actively pursued.  It is worth noting that these initial responses show a greater effect on brain volume loss for ibudilast than was seen in similar trial results for ocrelizumab (Ocrevus), which went on to be the first approved treatment for PPMS.