There is insufficient evidence of efficacy of individual antioxidants, or antioxidants in general, in the treatment of people with amyotrophic lateral sclerosis. One study reported a mild positive effect but this was not supported in our analysis. If future trials of antioxidant medications are performed, careful attention should be given to sample size, outcome measures, and duration of the trials. The high tolerance and safety, and relatively low cost of vitamins C and E, explain the continuing use of these vitamins by physicians and people with amyotrophic lateral sclerosis. While there is no substantial clinical trial evidence to support their clinical use, there is no clear contraindication.
Phase II trial of CoQ10 for ALS finds insufficient evidence to justify phase III.
Amyotrophic lateral sclerosis (ALS) is a devastating, and currently incurable, neuromuscular disease in which oxidative stress and mitochondrial impairment are contributing to neuronal loss. Coenzyme Q10 (CoQ10), an antioxidant and mitochondrial cofactor, has shown promise in ALS transgenic mice, and in clinical trials for neurodegenerative diseases other than ALS. Our aims were to choose between two high doses of CoQ10 for ALS, and to determine if it merits testing in a Phase III clinical trial.
                We designed and implemented a multicenter trial with an adaptive, two-stage, bias-adjusted, randomized, placebo-controlled, double-blind, Phase II design (n = 185). The primary outcome in both stages was a decline in the ALS Functional Rating Scale-revised (ALSFRSr) score over 9 months. Stage 1 (dose selection, 35 participants per group) compared CoQ10 doses of 1,800 and 2,700 mg/day. Stage 2 (futility test, 75 patients per group) compared the dose selected in Stage 1 against placebo.
                Stage 1 selected the 2,700 mg dose. In Stage 2, the pre-specified primary null hypothesis that this dose is superior to placebo was not rejected. It was rejected, however, in an accompanying prespecified sensitivity test, and further supplementary analyses. Prespecified secondary analyses showed no significant differences between CoQ10 at 2,700 mg/day and placebo. There were no safety concerns.
                CoQ10 at 2,700 mg daily for 9 months shows insufficient promise to warrant Phase III testing. Given this outcome, the adaptive Phase II design incorporating a dose selection and a futility test avoided the need for a much larger conventional Phase III trial.