RARE Daily

A Phase 3 Failure for Amylyx May Lead to Pulling ALS Drug from Market

March 8, 2024

Rare Daily Staff

Amylyx Pharmaceuticals said it will consider removing its ALS drug Relyvrio from the market after topline results from its phase 3 study showed it failed to meet prespecified primary and secondary endpoints.

Shares of Amylyx fell more than 80 percent in early trading following the news.

Amylyx has voluntarily decided to pause promotion of the medication while it engages with regulatory authorities and the broader ALS community to discuss the results from its PHOENIX study and decide the future of Relyvrio. It said among the decisions it is weighing will be a possible voluntary withdrawal of Relyvrio from the market. For now, the company said Relyvrio and its related patient support program will continue to be available for people living with ALS.

“We will be led in our decisions by two key principles: doing what is right for people living with ALS, informed by regulatory authorities and the ALS community, and by what the science tells us, said Justin Klee and Joshua Cohen, co-CEOs of Amylyx in a prepared statement. The company expects to decide on what actions it will take within the next eight weeks.

Relyvrio is an oral combination therapy for amyotrophic lateral sclerosis (ALS), a rare, progressive and fatal neurodegenerative disorder caused by motor neuron death in the brain and spinal cord. Motor neuron loss in ALS leads to deteriorating muscle function, the inability to move and speak, respiratory paralysis, and eventually, death. More than 90 percent of people with ALS have sporadic disease, showing no clear family history. People living with ALS have a median survival of approximately two years from diagnosis.

The approval of Relyvrio was based on a multicenter phase 2 clinical trial in 137 participants with ALS encompassing a 6-month randomized placebo-controlled phase and an open-label extension long-term follow-up phase. The trial met its primary efficacy endpoint.

Though it won approval in 2022, there was controversy surrounding it as reviewers and others questioned whether there was adequate data to support approval. There has been growing tension within the FDA and between regulators and the rare disease patient community over the appropriate threshold for evidence needed to approve a drug when there is an unmet need. Some patient advocates have complained that the agency has grown too conservative in striking a balance between evidence and need. The new study should add fuel to critics of FDA approvals based on data from small studies.

Photo: Joshua Cohen, co-CEO of Amylyx

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