Amylyx’s withdrawn-from-market Relyvrio has failed to make an impact on primary or secondary endpoints in a rare neurodegenerative disease, prompting the company to discontinue the program.
Oral therapy Relyvrio, which Amylyx is again referring to as AMX0035, was tested in progressive supranuclear palsy (PSP), a fatal and rapidly progressing condition that impacts mobility, eye movements, swallowing and speech. Currently, there aren’t any approved treatments for the disease.
Amylyx’s phase 2/3b study was measuring AMX0035’s impact on disease progression and severity using a 28-item, condition-specific scale. The phase 2 portion of the trial found no difference in patients receiving AMX0035 compared to placebo at 24 weeks, according to an Aug. 27 company release.
Given the results, the company has discontinued the phase 2b trial, plus a related open-label extension study. Amylyx has also terminated plans for the phase 3 portion of the study.
The company noted that AMX0035 was generally well-tolerated, with safety data consistent with prior studies.
“We set a high bar for AMX0035 in PSP and made a commitment to base our decision-making on the totality of the data and the potential for clinically meaningful outcomes for those living with PSP,” Amylyx Chief Medical Officer Camille Bedrosian, M.D., said in the release. “While we are disappointed in these results, we believe these data will inform the PSP trial literature as well as deepen scientific understanding of this devastating disease.”
AMX0035 is a combination of sodium phenylbutyrate and taurursodiol that was previously sold as Relyvrio and Albrioza for amyotrophic lateral sclerosis (ALS). The therapy had notched FDA approval in September 2022 based on phase 2 evidence that it significantly slowed the loss of physical function in patients with ALS.
But a few months later, Amylyx said Relyvrio had failed a phase 3 trial, missing all primary and secondary endpoints measuring functional improvement in ALS. Shortly thereafter, Amylyx chose to pull the drug from the market.
Amylyx still believes that the drug could offer benefits in Wolfram syndrome, a rare genetic disease that impacts about 3,000 Americans. The company is currently testing the therapy among 12 patients in an open-label phase 2 study.
The company’s highest priority, however, is avexitide, a potentially first-in-class GLP-1 in development for post-bariatric hypoglycemia. The asset was purchased from Eiger Biopharma in 2024 and is currently being evaluated in a phase 3 trial, dubbed Lucidity.
Patient recruitment for the study is expected to wrap by the end of this year, with topline data slated for 2026.
The company currently expects its cash runway to last through the end of 2026.