The results of the study showed no major effect of the drug on indicators of disease activity such as number or volume of new lesions or relapses. However, subjects on ibudilast, particularly the higher dose, had lower brain atrophy rates. A comparison of MRIs showed that ibudilast treatment was associated with fewer lesions converting to MRI "persistent black holes," an indication of lasting damage. In addition, after 24 months, those subjects who had been on ibudilast from the beginning were less likely to have progressed on the EDSS scale than those who were initially on placebo.
This is interesting, it's the exact opposite of the usual (reduction in lesions without effect on progression).