April 4 (Reuters) - Amylyx Pharmaceuticals ( AMLX ) 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% reduction in

its workforce. It had 384 full-time employees at the end of

2023.

WHY IT'S IMPORTANT:

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.

CONTEXT:

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.

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.

BY THE NUMBERS:

The drug, which has a list price of $158,000 per year in the

U.S., generated sales of about $381 million in 2023.

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% 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.

WHAT'S NEXT:

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.

(Reporting by Sriparna Roy in Bengaluru; Editing by Shilpi

Majumdar and Sriraj Kalluvila)