Safety, Tolerability and Activity Study of Ibudilast in Subjects With Progressive Multiple Sclerosis

Study Summary

This is a multicenter, randomized, double-blind, placebo-controlled, parallel-group study designed to evaluate the safety, tolerability and activity of ibudilast administered twice daily over a 96 week period in subjects with primary or secondary progressive multiple sclerosis who are currently untreated with long-term MS disease modifying therapy (DMT) or who are receiving either glatiramer acetate (GA) or interferon beta-1, any formulation (IFNβ-1A \[Avonex, Rebif\] or IFNβ-1B \[Betaseron, Extavia\]). Study drug or placebo will be administered to a total of 250 male and female subjects from 21 to 65 years old, inclusive, in two treatment groups. Randomization of subjects will be stratified by disease status (primary progressive multiple sclerosis or secondary progressive multiple sclerosis) and immunomodulating therapy status: current use of immunomodulating therapy or no current use of immunomodulating therapy. The study will consist of a screening phase (up to 30 days) followed by a treatment phase (96 weeks) and a follow-up visit (1 month post Week 96 visit). Following the screening phase, subjects who continue to meet entry criteria will be randomly assigned to 1 of 2 treatment groups: doses up to ibudilast 100 mg/day or matching-placebo in a 1:1 ratio. Study drug will be administered twice daily (BID), e.g., ibudilast 50 mg or placebo taken in the morning and evening).

Primary Outcome

To evaluate the activity of ibudilast (100 mg/day) versus placebo at 96 weeks as measured by quantitative magnetic resonance imaging (MRI) analysis for whole brain atrophy using brain parenchymal fraction (BPF), calculated as the ratio of brain parenchymal tissue volume to the total volume contained within the brain surface contour.

Interventions

• DRUG Placebo oral capsule
• DRUG ibudilast