Sodium Phenylbutyrate and Ursodoxicoltaurine: First Approval

An oral, fixed-dose coformulation of sodium phenylbutyrate and ursodoxicoltaurine (ALBRIOZA™; hereafter denoted sodium phenylbutyrate/ursodoxicoltaurine) is being developed by Amylyx Pharmaceuticals for the treatment of neurodegenerative diseases. In June 2022, the coformulation received its first approval with conditions in Canada for the treatment of amyotrophic lateral sclerosis (ALS) in adults. The approval was based on results from the multicentre, phase II CENTAUR trial, in which slowing of ALS progression was demonstrated with sodium phenylbutyrate/ursodoxicoltaurine relative to placebo. This article summarizes the milestones in the development of sodium phenylbutyrate/ursodoxicoltaurine leading to this first approval.