ALS drug development: Reflections from the past and a way forward

Tremendous advances in our understanding of pathogenesis of amyotrophic lateral sclerosis (ALS) have provided a rich pipeline of drugs for clinical trialists. At least 32 unique compounds have been tested. Nevertheless, riluzole is currently the only treatment that prolongs survival. We present a critical overview of past clinical trials, how therapies are selected for testing in people, challenges with ALS clinical trial design and conduct, and ways to best move forward.