A placebo arm is not always necessary in clinical trials of amyotrophic lateral sclerosis.

Riluzole is currently the only approved medication for amyotrophic lateral sclerosis (ALS). While other potential neuroprotective agents have been tested in clinical trials, none has been effective, and few symptomatic treatments have been studied. Randomized placebo-controlled trials are necessary to establish the effectiveness of a drug, but an increasing number of potential therapies combined with limited resources means that only a few drugs at a time can be tested for efficacy in ALS. Therefore, priority must be given to agents that show an advantage in early phase trials before proceeding to Phase III efficacy trials. New strategies are being used to screen different agents, along with their correct dose, in a variety of neurological illnesses, including ALS. Early phase trial designs conducted without a placebo arm improve efficiency, reduce cost, and appeal to patients. Dose-ranging, futility, and selection trials are examples of Phase I and II trial designs that can be conducted without placebo groups.