A Randomized, Double-blind, Placebo-controlled Trial of DL-3-n-butylphthalide in Amyotrophic Lateral Sclerosis Patients

Background: To determine the efficacy and safety of DL-3-n-butylphthalide (NBP) for the treatment of amyotrophic lateral sclerosis (ALS).Methods: A randomized, double-blind, placebo-controlled trial was performed at 19 ALS clinical centers of the Chinese ALS Association. Patients with definite or probable ALS were randomly treated with NBP or placebo for 12 months. The Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) score was the primary endpoint and was evaluated every 3 months. Secondary endpoints included survival and tracheotomy incidence, total Medical Research Council (MRC) score, percentage of predicted forced vital capacity (FVC), and clinical global impression scale score assessed using the visual analog scale. Results: Between November 23, 2015 and November 22, 2017, 312 ALS patients were enrolled and randomly allocated to either the NBP group (156 patients) or placebo group (156 patients). Ninety-three patients in the NBP group and 92 patients in the placebo group were included in the primary end point analysis. There was no significant difference in the ALSFRS-R score, total MRC score, or clinical global impression between the two groups after treatment. The NBP group exhibited a mild trend of less decrease in the percentage of predicted FVC between baseline and the 12-month visit than the placebo group (least-squares mean change from baseline ± standard error: -7.34±4.28, 95％CI(-15.24,0.56), p=0.0335). Adverse events were reported in 56.5% of patients in the placebo group and 68.8% of patients in the NBP group (χ2=2.99, P=0.0838). No serious adverse event related to treatment occurred.Conclusion: we found no evidence that NBP improved the ALSFRS-R score in patients with ALS. The results suggest a mild trend in the percentage of predicted FVC decreased slowly in the NBP treatment group than in the placebo group.Trial registration: A Multi-center, Randomized, Double Blinding, Placebo-Controlled Clinical Trial of Dl-3-Butylphthalide in the Treatment of Amyotrophic Lateral Sclerosis, ChiCTR-IPR-15007365, Registered 1 November 2015, http://www.chictr.org.cn/showproj.aspx?proj=12354