Amylyx pulls ALS drug Relyvrio from market in US, Canada

Amylyx Pharmaceuticals Inc. announced Relyvrio, its amyotrophic lateral sclerosis therapeutic, will be removed from the market in the United States and Canada, effective immediately.

According to a company release, Relyvrio (sodium phenylbutyrate and taurursodiol) will not be available to new patients. Those currently prescribed the drug and who wish to remain on the treatment, in consultation with their physician, will be transitioned to a free drug program, Amylyx said.

The decision for removal was made based on topline results from the PHOENIX trial, a phase 3 randomized, double-blind, placebo-controlled study conducted at 65 sites across the U.S. and Europe evaluating safety and efficacy of Relyvrio in 664 adults with the neuromuscular condition.

The study’s primary efficacy outcome was change from baseline in the ALS Functional Rating Scale-Revised total score at 48 weeks. Results from the study showed that Relyvrio did not outperform placebo on the functional rating scale despite showing favorable safety and tolerability profiles.

Amylyx said it intends to continue to collect available data on survival at the encouragement of ALS specialists, while allowing the trial’s open-label extension to continue.

The oral, fixed-dose combination therapy, also known as AMX0035, was approved by the FDA in September 2022.

“While this is a difficult moment for the ALS community, we reached this path forward in partnership with the stakeholders who will be impacted and in line with our steadfast commitment to people living with ALS and other neurodegenerative diseases,” Amylyx co-CEOs Joshua Cohen and Justin Klee said in the release.

Amylyx said it will advance programs involving AMX0035 in Wolfram syndrome and progressive supranuclear palsy, as well as to investigate AMX0114, an antisense oligonucleotide targeting calpain-2, for ALS.

The ALS Association provided a statement to Healio in response to this announcement.

“We commend Amylyx for pulling Relyvrio off the market while still ensuring that people living with ALS can access the drug if they believe it is helping them,” the group stated. “Safe and potentially effective treatments can be made accessible rapidly until further research can confirm their efficacy. There are more than 40 [additional] potential treatments in the pipeline, and we are focused on trying to advance the safe and effective ones as quickly as possible.”

Editor's note: This story was updated on April 8, 2024, to include a statement from the ALS Association.

Reference:

Amylyx Pharmaceuticals announces topline results from global phase 3 PHOENIX trial of AMX0035 in ALS. https://investors.amylyx.com/news-releases/news-release-details/amylyx-pharmaceuticals-announces-topline-results-global-phase-3. Published March 8, 2024. Accessed Apr. 4, 2024.