FDA Approves New Treatment Option for Patients With ALS


The US FDA approved Relyvrio (sodium phenylbutyrate/taurursodiol) to treat patients with amyotrophic lateral sclerosis (ALS), commonly referred to as Lou Gehrig’s disease.

“This approval provides another important treatment option for ALS, a life-threatening disease that currently has no cure,” said Billy Dunn, MD, Director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research. “The FDA remains committed to facilitating the development of additional ALS treatments.”

ALS is a rare disease that attacks and kills the nerve cells that control voluntary muscles. Voluntary muscles produce movements such as chewing, walking, breathing, and talking. ALS causes the nerves to lose the ability to activate specific muscles, which causes the muscles to become weak and leads to paralysis. ALS is a progressive disease that continues to get worse over time. Most cases will result in death from respiratory failure, usually within three to five years from when the symptoms first appear. Approximately 5,000 individuals in the United States are diagnosed with ALS annually, and approximately 20,000 Americans are currently living with the disease.

Relyvrio can be taken orally by combining one packet in 8 ounces of room temperature water. It can also be administered through a feeding tube. The recommended dosage for the first three weeks is one packet (3 grams sodium phenylbutyrate and 1-gram taurursodiol) daily. After 3 weeks, the dosage increases to one packet twice a day. The medication can be taken before a snack or meal.

The efficacy of Relyvrio for the treatment of ALS was demonstrated in a 24-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. In the trial, 137 adult patients with ALS were randomized to receive either Relyvrio or placebo. The patients treated with Relyvrio experienced a slower rate of decline on a clinical assessment of daily functioning compared to those receiving a placebo. Additionally, longer overall survival was observed in a post hoc, long-term analysis of patients who originally received Relyvrio versus those who originally received placebo.

The most common adverse reactions experienced with Relyvrio were diarrhea, abdominal pain, nausea, and upper respiratory tract infection. Relyvrio contains taurursodiol, a bile acid, which may cause worsening diarrhea in patients with disorders that interfere with bile acid circulation. These patients should consider consulting with a specialist before taking Relyvrio. The prescribing information includes additional information on risks associated with Relyvrio.

The FDA granted this application Priority Review designation. It also received orphan drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases. The FDA granted the approval of Relyvrio to Amylyx Pharmaceuticals Inc.