Open-label 24-week extension study of edaravone (MCI-186) in amyotrophic lateral sclerosis

We aimed to explore the longer-term efficacy and safety of edaravone in an active-treatment extension period following the double-blind period of the second phase III study. Patients who met all the following criteria (scores >2 points on all 12 items of the revised amyotrophic lateral sclerosis functional rating scale [ALSFRS-12], forced vital capacity >80%, definite or probable ALS, and disease duration <2 years) were randomised to 60 mg intravenous edaravone or placebo for six cycles in the double-blind period, and then offered the opportunity to proceed to this 24-week open-label extension period. One hundred and twenty-three of 137 patients continued to the extension period: 65 edaravone-edaravone (E-E group) and 58 placebo-edaravone (P-E group). Change (mean standard deviation; SD) in the ALSFRS-R score from baseline in the double-blind period was 4.1 +/- 3.4 and 6.9 +/- 5.1 in the E-E group and P-E group, respectively, while it was 8.0 +/- 5.6 in the E-E group and 10.9 perpendicular to 16.9 in the P-E group over the whole 48-week period. The ALSFRS-R score changed almost linearly throughout Cycles 1-12 in the E-E group. The most commonly reported adverse events were constipation, dysphagia, and contusion. There was no sudden deterioration in the ALSFRS-R score of the E-E group. No safety concerns related to edaravone were detected.