Safety and efficacy of trehalose in amyotrophic lateral sclerosis (HEALEY ALS Platform Trial): an adaptive, phase 2/3, double-blind, randomised, placebo-controlled trial

Abstract

Background: Trehalose is a disaccharide that activates autophagy pathways in animal models of neurodegenerative diseases, with the potential to catalyse clearance of toxic, misfolded proteins in motor neurons and slow disease progression in amyotrophic lateral sclerosis (ALS). We aimed to evaluate the safety and efficacy of trehalose in individuals with ALS.

Methods: The HEALEY ALS Platform Trial is a perpetual, adaptive, phase 2/3, randomised, double-blind, multi-regimen trial conducted at 60 geographically diverse sites in the USA. In the current regimen, adults with clinically possible, probable, laboratory-supported probable, or definite ALS, defined by the revised El Escorial criteria, were randomly allocated (3:1), stratified by use of edaravone and riluzole, to receive trehalose 0·75 g per kg intravenously weekly over 24 weeks, or matching placebo. The primary outcome was a composite of the relative rate of disease progression, as measured by the Revised ALS Functional Rating Scale (ALSFRS-R), and survival over 24 weeks, estimated in a Bayesian shared-parameter model. The study included prespecified stopping rules for futility; interim analyses occurred every 12 weeks. The primary outcome was analysed according to the intention-to-treat principle in all participants in the trehalose group, the placebo group within the regimen, and placebo groups from other contributing regimens; the safety analysis population was comprised of all participants who initiated treatment. This study is registered with ClinicalTrials.gov, NCT05136885.

Findings: Between Feb 21, 2022, and Feb 17, 2023, 1021 participants were screened for the platform trial and 171 were assigned to the trehalose regimen. Of these, 161 participants met eligibility criteria, with 120 randomly allocated to trehalose and 41 to regimen-specific placebo. 164 participants randomly allocated to placebo in other regimens were added for analysis (totalling 205 placebo recipients). The disease rate ratio for change in ALSFRS-R and survival was 0·87 (95% credible interval 0·665-1·102, posterior probability of superiority 0·877). Serious adverse events occurred in 19 (16%) participants in the trehalose group and three (7%) participants in the regimen-only placebo group, leading to premature discontinuations in 14 (12%) versus one (2%), respectively. Fatal treatment-emergent adverse events occurred in seven participants in the trehalose group and none in the regimen-only placebo group. No death was considered related to the trial drug. The most common cause of death was respiratory failure, consistent with the natural history of ALS.

Interpretation: Trehalose was well tolerated but there was no evidence to suggest a difference in ALS disease progression compared with placebo in this study. No statistical benefit was seen in secondary clinical or biomarker measures, suggesting that trehalose at this dosage is unlikely to be efficacious for treatment of ALS.

Funding: AMG Charitable Foundation, Tackle ALS, the ALS Association, ALS Finding a Cure, the Muscular Dystrophy Association, ALS ONE, the Arthur M Blank Family Foundation, I AM ALS, Tambourine ALS Collaborative, and other community fundraising initiatives and donors. Study drug and partial regimen-related funding was provided by Seelos.