In vitro metabolism, pharmacokinetics and drug interaction potentials of emvododstat, a DHODH inhibitor

Emvododstat was identified as a potent inhibitor of dihydroorotate dehydrogenase and is now in clinical development for the treatment of acute myeloid leukaemia and COVID-19. The objective of this paper is to evaluate the metabolism, pharmacokinetics, and drug interaction potentials of emvododstat. Emvododstat showed high binding to plasma protein with minimal distribution into blood cells in mouse, rat, dog, monkey, and human whole blood. O-Demethylation followed by glucuronidation appeared to be the major metabolic pathway in rat, dog, monkey, and human hepatocytes. CYP2C8, 2C19, 2D6, and 3A4 were involved in O-desmethyl emvododstat metabolite formation. Both emvododstat and O-desmethyl emvododstat inhibited CYP2D6 activity and induced CYP expression to different extents in vitro. Emvododstat and O-desmethyl emvododstat inhibited BCRP transporter activity but did not inhibit bile salt transporters and other efflux or uptake transporters. Neither emvododstat nor O-desmethyl emvododstat was a substrate for common efflux or uptake transporters investigated. Emvododstat is bioavailable in mice, rats, dogs, and monkeys following a single oral dose. The absorption was generally slow with the mean plasma T-max ranging from 2 to 5 h; plasma exposure of O-desmethyl emvododstat was lower in rodents, but relatively higher in dogs and monkeys.