Objective-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.Methods-We designed and implemented a multi-center trial with an adaptive, two-stage, biasadjusted, randomized, placebo-controlled, double-blind, Phase II design (n=185). The primary outcome in both stages was 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.Results-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 Kaufmann et al. Page 2Ann Neurol. Author manuscript; available in PMC 2010 August 1.
NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript accompanying pre-specified sensitivity test, and further supplementary analyses. Pre-specified secondary analyses showed no significant differences between CoQ10 at 2,700 mg/day and placebo. There were no safety concerns.Interpretation-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.ALS is an orphan disease with an average annual incidence rate of 1 to 2 per 100,000 person-years, 1-3 and, because the disease typically leads to death within 2 to 4 years of onset, 4 a relatively low prevalence of 4-6 per 100,000 people. 5 About 10% of ALS cases are familial, and about 15 to 20% of autosomal dominant familial ALS patients have mutations the superoxide dismutase 1 (SOD1) gene. 6 The pathogenesis remains incompletely understood, but several lines of evidence suggest that oxidative stress plays an important role. SOD 1 is an enzyme that plays a role in detoxifying free radicals 7 . In a transgenic mouse model of familial ALS, there is increased oxidative stress. 8 In patients with sporadic ALS, oxidative stress indicators were found in plasma, urine, and CSF. 9-13 Mitochondrial impairment in ALS is supported by several findings in vitro, animal studies, and patients. In an ALS cell culture model, motor neuron cell lines harboring SOD1 mutations have morphologically abnormal mitochondria and impaired respiratory chain function. 14 Respiratory chain dysfunction has also been described in an ALS mouse model. 15 In spinal cord tissue of ALS patients, mutant mtDNA molecules were incre...