Stereoselective hydroxylation by CYP2C19 and oxidation by ADH4 in thein vitrometabolism of tivantinib

Abstract

1. In prior studies, it has been shown that tivantinib is extensively metabolized in humans to many oxidative metabolites and glucuronides. In order to identify the responsible enzymes, we investigated the in vitro metabolism of tivantinib and its four major circulating metabolites. 2. The primary isoforms involved in the elimination of tivantinib were CYP2C19 and CYP3A4/5. CYP2C19 showed catalytic activity for the formation of M5 (hydroxylated metabolite), but not for M4 (a stereoisomer of M5), whereas CYP3A4/5 catalyzed the formation of both metabolites. For the elimination of M4, M5 and M8 (keto-metabolite), CYP3A4/5 was the major cytochrome P450 isoform and UGT1A9 was mainly involved in the glucuronidation of M4 and M5. 3. ADH4 was identified as one of the major alcohol dehydrogenase isoforms contributing to the formation of M6 (sequential keto-metabolite of M4 and M5) and M8. The substrate preference of ADH for M4, and not M5, was observed in the formation of M6. 4. In conclusion, CYP2C19, CYP3A4/5, UGT1A9 and ADH4 were the primary drug metabolizing enzymes involved in the in vitro metabolism of tivantinib and its metabolites. The stereoselective hydroxylation by CYP2C19 and substrate stereoselectivity of ADH4-catalyzed oxidation in the in vitro metabolism of tivantinib was discovered.

Non-P450 Drug-Metabolizing Enzymes: Contribution to Drug Disposition, Toxicity, and Development

“…Of note, ADH4 protein was also detected by Western blotting not only in cytosolic fractions but also in the microsomal fractions, although the latter band was faint. Nishiya et al (22) also reported that the ADH-catalyzing oxidation of hydroxyltivantinib was detected in human liver microsomes, as well as in the cytosol. Further analyses of the subcellular localization of ADH enzymes are therefore necessary.…”

“…A metabolite of celecoxib hydroxylated at the methyl group on the benzene ring by CYP2C9 is further oxidized by ADH1C and ADH4 (21). A metabolite of tivantinib hydroxylated at carbon atoms adjacent to benzene or the pyrrole ring by CYP3A is also oxidized by ADH1A and ADH4 (22). A hydroxylated metabolite of vortioxetine at the methyl group on the benzene ring by CYP2D6 is oxidized by ADH, although the isoform has not been identified (23).…”

Pharmacogenetics of the systemic treatment in advanced hepatocellular carcinoma

“…Indeed, despite controversies regarding its mechanism of action, two phase II clinical trials (NCT01575522, NCT00988741) have demonstrated that tumors with high levels of MET present a high degree of response to tivantinib treatment[145,146]. In term of pharmacokinetics, tivantinib is metabolized by CYP2C19, CYP3A4/5, UGT1A9, and alcohol dehydrogenase isoform 4[147]. CYP2C19 shows catalytic activity for the formation of the hydroxylated metabolite (M5), whereas CYP3A4/5 catalyzes formation of M5 and its stereoisomer (M4).…”

“…CYP2C19 shows catalytic activity for the formation of the hydroxylated metabolite (M5), whereas CYP3A4/5 catalyzes formation of M5 and its stereoisomer (M4). Moreover, CYP3A4/5 represents the major cytochrome isoform involved in the elimination of M4, M5, and the keto-metabolite (M8), and together with UGT1A9, involved in the glucuronidation of M4 and M5[147]. Finally, the alcohol dehydrogenase isoform 4, through a sequential keto-metabolite of M4 and M5 and through M8, leads to the formation of M6[147].…”

“…Moreover, CYP3A4/5 represents the major cytochrome isoform involved in the elimination of M4, M5, and the keto-metabolite (M8), and together with UGT1A9, involved in the glucuronidation of M4 and M5[147]. Finally, the alcohol dehydrogenase isoform 4, through a sequential keto-metabolite of M4 and M5 and through M8, leads to the formation of M6[147]. Between 2010 and 2014, two phase I trials (NCT01069757, NCT01656265) in Japanese patients with advanced solid tumors examined the safety, pharmacokinetics, and preliminary efficacy of tivantinib as a single agent to determine recommended phase II dose according to CYP2C19 polymorphisms[148,149].…”