Amylyx's ALS Treatment's Fate Uncertain Following Phase III Trial Failure

Amylyx Pharmaceuticals, a biotech firm based in Cambridge, Massachusetts, has faced a setback in its efforts to treat amyotrophic lateral sclerosis (ALS). The company's drug Relyvrio, which was approved by the FDA as the third ALS treatment in the past eighteen months, has failed to meet its primary and secondary goals in a Phase III trial known as PHOENIX. The drug was initially given the green light following promising results from a Phase II trial that suggested it could slow the disease's progression and extend patients' lives.

However, the latest findings indicate that Relyvrio did not show a significant difference from the placebo in terms of the ALS Functional Rating Scale Revised (ALSFRS-R) score change at 48 weeks. The drug also did not demonstrate a notable effect in a group of participants who met the criteria of the previous CENTAUR trial, which was a Phase II study. Secondary measures such as the ALS Assessment Questionnaire-40 (ALSAQ-40) and slow vital capacity (SVC) changes were also not significantly different from the placebo.

The PHOENIX trial involved 664 ALS patients who were randomly assigned to receive either Relyvrio or a placebo, alongside standard care. Participants were also allowed to continue taking other ALS medications, such as riluzole and edaravone. Safety data from the trial were consistent with the Phase II findings, with no new safety concerns arising.

The co-CEOs of Amylyx, Justin Klee and Josh Cohen, expressed their surprise and disappointment at the PHOENIX results, especially after the positive outcomes from the CENTAUR trial. They did not provide a timeline for the release of survival data from the PHOENIX trial and have acknowledged the impact of the news on the ALS community.

Previously, Klee and Cohen had shown optimism about the drug's potential, with Cohen stating, "We go in quite optimistic that we'll see something very, very exciting for people living with ALS and the ALS community." Despite the setback, the company remains committed to its promise to withdraw Relyvrio from the market if the Phase III data were not positive.

Amylyx intends to engage with regulatory authorities, the ALS community, and clinical experts to discuss the next steps, which may include the voluntary withdrawal of the product. The company also believes that the insights gained from the PHOENIX study will contribute to the advancement of future ALS research.