The effect of cladribine on T(1) 'black hole' changes in progressive MS

We compared the changes of the volumes of T(1)-hypointense lesions seen on the magnetic resonance imaging scans of the brain from 159 progressive multiple sclerosis (MS) patients who were enrolled in a double-blind, placebo-controlled trial assessing the efficacy of two doses of cladribine. Although in patients treated with cladribine there was a tendency to have a lower increase of T(1)-hypointense lesion volumes than those treated with placebo, no statistically significant effect of cladribine on T(1)-hypointense lesion accumulation was found over the one-year double-blind phase. Furthermore, no significant treatment effect was also detected in a subset of 22 patients who received placebo during the double-blind phase of the study and cladribine during the subsequent one-year open-label phase. We conclude that cladribine does not have a major impact on the mechanisms leading to severe tissue destruction in progressive MS.