Amylyx Pharmaceuticals has announced plans to take sodium phenylbutyrate–taurursodiol (Relyvrio and Albrioza), its drugs for amyotrophic lateral sclerosis (ALS), off the market in the United States and Canada.
The action stems from disappointing topline results from the phase 3 PHOENIX trial released March 8.
As reported previously by Medscape Medical News, sodium phenylbutyrate–taurursodiol offered no significant improvements after 48 weeks compared with placebo, failing to meet the randomized controlled trial”s primary or secondary endpoints.
The data prompted the watchdog group Public Citizen to call for the immediate removal of sodium phenylbutyrate–taurursodiol from the market.
Based on the topline data, Amylyx said the drug will no longer be available for new patients as of April 4. Patients currently on the drug in the United States and Canada who, in consultation with their physician, want to remain on treatment can be transitioned to a free drug program, the company said in a statement.
“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,” Joshua Cohen and Justin Klee, co-CEOs of Amylyx, said in the statement.
“The decision to remove Relyvrio/Albrioza from the market and provide therapy free of charge for those who wish to continue was informed by the PHOENIX trial results, engagement with regulatory authorities, and discussions with the ALS community,” Cohen and Klee said.
Checkered History
The US Food and Drug Administration (FDA) approved the drug in September 2022. The decision followed an unusual review process that began in March 2022 with an initial recommendation from the FDA’s Peripheral and Central Nervous System Drugs Advisory Committee not to approve the drug due to insufficient evidence of efficacy.
The expert panel’s recommendation against approval was criticized by patients and other advocates for failing to consider the unmet medical need in ALS and the seriousness and lethality of the disease.
After updated data provided by the manufacturer and an aggressive campaign by patients with ALS and associated advocates, the FDA delayed its final ruling on the drug’s approval and reconvened the panel for a rare second review.
This time, the panel was not asked whether the data provided conclusive evidence of efficacy, rather whether the data were sufficient for approval. It also received broader latitude to consider the unmet medical need and lethality of ALS.
After this meeting, the committee did an about-face and voted seven to two in favor of the drug’s approval.
Amylyx continues to study the drug (also known as AMX0035) in Wolfram syndrome and progressive supranuclear palsy (PSP), as well as another agent, AMX0114, an antisense oligonucleotide targeting calpain 2, in ALS.