The effects of intervention with intravenous edaravone in Study 19 on hospitalization, tracheostomy, ventilation, and death in patients with amyotrophic lateral sclerosis.

Introduction/aims: Intravenous (IV) edaravone is a US Food and Drug Administration-approved treatment for amyotrophic lateral sclerosis (ALS), shown in clinical trials to slow physical functional decline. In this study we compared the effect of IV edaravone (edaravone-first group) versus placebo followed by IV edaravone (placebo-first group) on survival and additional milestone events.

Methods: This work is a post hoc analysis of Study 19/MCI186-19, which was a randomized, placebo-controlled, phase 3 study investigating IV edaravone versus placebo. Study 19 and its 24-week extension have been described previously (NCT01492686). Edaravone-first versus placebo-first group time to events for specific milestone(s) were analyzed post hoc. Time-to-event composite endpoints were time to death; time to death, tracheostomy, or permanent assisted ventilation (PAV); and time to death, tracheostomy, PAV, or hospitalization.

Results: The risk for death, tracheostomy, PAV, or hospitalization was 53% lower among patients in the edaravone-first vs placebo-first groups (hazard ratio = 0.47 [95% confidence interval 0.25 to 0.88], P = .02). The overall effect of IV edaravone on ALS progression could be seen in the significant separation of time-to-event curves for time to death, tracheostomy, PAV, or hospitalization. ALS survival composite endpoint analyses (ALS/SURV) suggested a treatment benefit (least-squares mean difference) for the edaravone-first versus the placebo-first group at week 24 (0.15 ± 0.05 [95% confidence interval 0.06 to 0.25], P < .01) and week 48 (0.11 ± 0.05 [95% confidence interval 0.02 to 0.21], P = .02).

Discussion: These analyses illustrate the value of timely and continued IV edaravone treatment, as earlier initiation was associated with a lower risk of death, tracheostomy, PAV, or hospitalization in patients with ALS.