Firazorexton (; development code TAK-994) is an experimental orexin 2 (OX<sub>2</sub>) receptor agonist first described in a 2019 patent filed by Takeda Pharmaceutical Company.
Firazorexton was studied by Takeda for the treatment of narcolepsy. It is a small-molecule and orally active compound and acts as a highly selective agonist of the orexin receptor 2 (OX<sub>2</sub>) with >700-fold selectivity over the orexin receptor 1 (OX<sub>1</sub>). Firazorexton is related to danavorexton (TAK-925).
The compound reached phase 2 clinical trials for narcolepsy. However, clinical development was discontinued in October 2021 for safety reasons. More specifically, it produced severe drug-induced liver injury in phase 2 trials. This hepatotoxicity is unlikely to be related to firazorexton's orexin receptor agonism.