ALS drug will be pulled from Canada, U.S. markets after failed trial

Amylyx Pharmaceuticals will withdraw its amyotrophic lateral sclerosis (ALS) drug – its only product in the market – from the U.S. and Canada after the treatment failed in a key late-stage trial.

The drugmaker on Thursday also announced a 70 per cent reduction in its workforce. It had 384 full-time employees at the end of 2023.

The ALS drug, branded Relyvrio, was approved in 2022 after lobbying by patient groups who pointed to limited options to treat the potentially fatal disease.

ALS causes progressive paralysis and death, and affects roughly 60,000 people in the U.S. and Europe.

Approval followed a rare turnaround by the U.S. Food and Drug Administration’s advisers. They backed the drug months after rejecting it for a lack of “substantially persuasive” data.

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The approval was based on mid-stage trial data in 137 patients that showed the treatment slowed disease progression and extended life expectancy.

However, a larger late-stage study failed to confirm the reported benefit of slowing disease progression, with no significant difference in patients treated with Relyvrio and placebo.

The drug, which has a list price of  USD$158,000 per year in the U.S., generated sales of about $381 million in 2023.

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Amylyx expects to incur charges of about $19 million as part of its restructuring, expected to be completed by the end of the third quarter.

Shares closed about 83 per cent lower and more than $1 billion was wiped out from its market value on March 8 after the company disclosed it was considering withdrawing the treatment.

The company will advance trials of its lead experimental drug AMX0035 in inherited condition Wolfram syndrome and neurological disorder progressive supranuclear palsy. It will also focus on AMX0114 in ALS.