PB-TURSO To Be Submitted to FDA for Approval to Treat Amyotrophic Lateral Sclerosis 

In the phase 2 CENTAUR trial (NCT03127514), participants with amyotrophic lateral sclerosis (ALS) treated with a sodium phenylbutyrate (PB)/ taurursodiol (TURSO) combination (AMX0035; Amylyx Pharmaceuticals, Cambridge, MA) had slowing of disease progression and increased survival. Phase 3 trials are ongoing and Amylyx has announced they will submit a new drug application (NDA) to the Food and Drug Administration (FDA) in the coming months. The decision to file an NDA comes after regulatory meetings with the FDA.

In the randomized placebo-controlled trial, 137 participants were treated with PB-TURSO or placebo. Participants treated with PB/TURSO vs placebo had statistically significant slowing of disease progression as measured by the ALS Functional Rating Scale-Revised (ALSFRS-R). In the open-label extension study (NCT03488524), participants have been followed for over 3 years. Interim survival analysis at 3 years showed that those who had PB/TURSO during the blinded phase had a 44% lower risk of death. Median survival in those given PB/TURSO vs placebo in those first 6 months was 6.5 months longer than that seen in people who took placebo. Gastrointestinal side effects occurred more frequently with PB/TURSO. 

“We are thrilled to move toward the U.S. submission of an NDA for AMX0035 and look forward to continuing to work with the FDA,” said Joshua Cohen, co-CEO, chairman and cofounder of Amylyx. “For those living with ALS, time is the most important resource, and we remain focused on advancing AMX0035 through the clinical development process as efficiently as possible,” added Justin Klee, coCEO, director and cofounder of Amylyx. “We’re endlessly grateful for all of the support and efforts of ALS Finding a Cure, the ALS Association, I AM ALS, the Healey & AMG Center at Mass General and the Northeast ALS Consortium, and all CENTAUR trial participants for their critical involvement as we approach this milestone.”

“AMX0035 has shown potential to provide those living with ALS and their families hope for the future,” said Sabrina Paganoni, MD, PhD, principal investigator of the CENTAUR trial, investigator at the Healey & AMG Center for ALS at Massachusetts General Hospital and Assistant Professor of PM&R at Harvard Medical School and Spaulding Rehabilitation Hospital. “We are very excited to learn of this positive development and optimistic that AMX0035 may make a real difference in the lives of people with ALS around the world.”

The phase 3 PHOENIX trial (NCT05021536) of PB/TURSO for ALS is also planned and will enroll approximately 600 participants. Amylyx is also exploring the possibility for an Expanded Access Program (EAP) in the US. Further information about the EAP is expected in fourth quarter 2021.