Edaravone efficacy in amyotrophic lateral sclerosis with reduced forced vital capacity: Post-hoc analysis of Study 19 (MCI186-19) [clinical trial NCT01492686].

BACKGROUND

Edaravone slowed the rate of functional decline in subjects with amyotrophic lateral sclerosis (ALS) in phase 3 study MCI186-19 (Study 19). One of the Study 19 inclusion criteria was forced vital capacity (FVC) ≥80% of predicted (≥80%p). Therefore, the study provided no information on edaravone efficacy in subjects with FVC <80%p. In Study 19, 24-week, double-blind treatment was followed by open-label treatment where all subjects received edaravone. At 24 weeks, some subjects had FVC <80%p (FVC24 <80%p). This allowed for post-hoc assessment of the effects of edaravone in subgroups of subjects with FVC24 ≥80%p vs <80%p.

OBJECTIVE

To address the question of the efficacy of edaravone in ALS patients with FVC <80%p.

METHODS

Post-hoc analysis of Study 19 comparing edaravone efficacy at week 48 in subjects with FVC24 ≥80%p vs <80%p.

RESULTS

With edaravone treatment, subjects in both the FVC24 ≥80%p and the FVC24 <80%p subgroups experienced a reduction in ALS Functional Rating Scale-Revised (ALSFRS-R) score loss vs placebo subjects through week 48. For the FVC24 ≥80%p subgroup, the changes in ALSFRS-R scores from baseline to week 48 were -7.63 for edaravone-edaravone vs -9.69 for placebo-edaravone, a difference of 2.05 (P = .034; 95% CI: 0.16, 3.94). For the FVC24 <80%p subgroup, the changes in ALSFRS-R scores from baseline to week 48 were -10.26 for edaravone-edaravone vs -15.20 for placebo-edaravone, a difference of 4.94 (P = .0038; 95% CI: 1.64, 8.25). Linear regression analysis indicated that, in the FVC24 <80%p subgroup, there was a notable change in the slope of the ALSFRS-R score-vs-time graph after the start of edaravone treatment.

CONCLUSION

ALS subjects in the Study 19 placebo arm had a slowing in disease progression, even when edaravone was added with an FVC of <80%p prior to starting edaravone. A randomized, placebo-controlled study is needed to validate these post-hoc findings.

Déclaration de conflit d'intérêts

The authors of this paper have read the journal’s policy and have the following competing interests: SA and SL are paid employees of MTPA. Authors BRB, THP, and MWP are consultants for MTPA, but did not receive any compensation for their work on this study or for writing this manuscript. JZ is a paid employee of Princeton Pharmatech. There are no patents, products in development or marketed products associated with this research to declare. This does not alter our adherence to PLOS ONE policies on sharing data and materials.