Long-term outcomes of edaravone in amyotrophic lateral sclerosis in South Korea: 72-week observational study

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease characterized by the gradual loss of upper and lower motor neurons that leads to progressive muscle atrophy and weakness. Edaravone, a free-radical scavenger, was approved as an ALS treatment in 2015 in South Korea. METHODS: This study investigated the long-term effects and safety of edaravone by reviewing the medical records of 16 Korean patients with ALS who received extended edaravone between 2015 and 2021 in a single tertiary ALS center. RESULTS: Among sixteen patients, eleven patients underwent extended edaravone therapy for more than 18 cycles (72 weeks). The mean monthly changes in the revised ALS Functional Rating Scale (ALSFRS-R) were − 0.96 ± 0.83 (0–24 weeks), − 0.70 ± 0.76 (24–48 weeks), − 1.18 ± 1.67 (48–72 weeks), and − 0.81 ± 0.60 (0–72 weeks). The mean decline in forced vital capacity (FVC) was 17.4 ± 24.1. The changes were significant in both ALSFRS-R (p < 0.001) and FVC (p = 0.048); however, the mean change in compound muscle action potential of phrenic nerves was not. Patients experienced only minor adverse events, which were well tolerated. CONCLUSIONS: This study verifies previous reported outcomes of edaravone in 16 Korean ALS patients, indicating a modest effect with a favorable safety profile.