Liminal BioSciences Inc. announced that it has discontinued development of fezagepras. The decision to discontinue the development of fezagepras is based on results from the Phase 1a single ascending dose clinical trial, which indicated that fezagepras was significantly inferior compared to Sodium Phenylbutyrate as a nitrogen scavenger. The Phase 1a SAD clinical trial of fezagepras initiated in May 2022 was designed as a head-to-head comparison with Sodium Phenylbutyrate to provides with further data to determine whether fezagepras was worth developing for one of the potential indications where nitrogen scavenging is beneficial.

The recommendation to stop the development program for fezagepras was not based on safety concerns.