ALS Drug Pulled From Market After Disappointing Trial Results

The amyotrophic lateral sclerosis (ALS) drug Relyvrio has been pulled from US and Canadian markets by its maker, Amylyx Pharmaceuticals, after topline trial data showed it worked no better than a placebo.

“Disappointing” trial results

ALS, also known as motor neuron disease (MND) or Lou Gehrig’s disease, is a deadly neurodegenerative disease that causes progressive loss of muscle control. It affects approximately 2 out of 100,000 people each year worldwide and typically causes death within just 5 years of diagnosis.

Despite its severity, there are only a handful of treatments currently available for the disease, most of which aim to slow down its progression.

In 2022, the US Food and Drug Administration (FDA) approved Relyvrio based on the results of a small clinical trial. Consisting of just 137 participants, the trial concluded that Relyvrio slowed disease progression and extended life expectancy. Median overall survival was 18.5 months in the placebo group compared to 25 months in the treated group.

The FDA’s approval came after an expert panel had previously rejected it due to a lack of “substantially persuasive” data. Patient groups had lobbied for its approval due to the lack of other suitable treatment options.

However, topline data from a new trial of 664 participants found that Relyvrio-treated patients fared no better than those who received a placebo; no statistically significant difference in disease progression was observed between the two groups.

“This is not the news we hoped for, and we understand that these trial results are extremely disappointing for people with MND as they show no substantial clinical benefit of AMX0035,” said the UK-based MND Association in a statement.

ALS remains an area of unmet need

Patients currently on the drug – a combination of sodium phenylbutyrate and taurursoidiol – will still be able to stay on the drug if they wish as part of a free drug program, but it will no longer be available for new patients.

“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. ALS is a fatal and heterogeneous disease with few treatment options, and creative solutions are needed,” the ALS Association said in a statement. “We believe the example of Relyvrio shows how the system can work. FDA approved Relyvrio based on solid safety data and positive efficacy data from a Phase 2 trial on function and survival.”

“There are more than 40 more potential treatments in the pipeline, and we are focused on trying to advance the safe and effective ones as quickly as possible.”