title: Role of hepatic transporters in the disposition and hepatotoxicity of a HER2 tyrosine kinase inhibitor CP-724,714.
abstract: CP-724,714, a potent and selective orally active HER2 tyrosine kinase inhibitor, was discontinued from clinical development due to unexpected hepatotoxicity in cancer patients. Based on the clinical manifestation of the toxicity, CP-724,714 likely exerted its hepatotoxicity via both hepatocellular injury and hepatobiliary cholestatic mechanisms. The direct cytotoxic effect, hepatobiliary disposition of CP-724,714, and its inhibition of active canalicular transport of bile constituents were evaluated in established human hepatocyte models and in vitro transporter systems. CP-724,714 exhibited direct cytotoxicity using human hepatocyte imaging assay technology with mitochondria identified as a candidate organelle for its off-target toxicity. Additionally, CP-724,714 was rapidly taken up into human hepatocytes, partially via an active transport process, with an uptake clearance approximately fourfold higher than efflux clearance. The major human hepatic uptake transporter, OATP1B1, and efflux transporters, multidrug resistance protein 1 (MDR1) and breast cancer resistance protein, were involved in hepatobiliary clearance of CP-724,714. Furthermore, CP-724,714 displayed a concentration-dependent inhibition of cholyl-lysyl fluorescein and taurocholate (TC) efflux into canaliculi in cryopreserved and fresh cultured human hepatocytes, respectively. Likewise, CP-724,714 inhibited TC transport in membrane vesicles expressing human bile salt export pump with an IC(50) of 16 microM. Finally, CP-724,714 inhibited the major efflux transporter in bile canaliculi, MDR1, with an IC(50) of approximately 28 microM. These results suggest that inhibition of hepatic efflux transporters contributed to hepatic accumulation of drug and bile constituents leading to hepatocellular injury and hepatobiliary cholestasis. This study provides likely explanations for clinically observed adverse liver effects of CP-724,714.
authors.affiliation: Pharmacokinetics, Dynamics, and Metabolism Department, Pfizer Global Research and Development, Groton, CT 06340.
authors.forename: Bo
authors.initials: B
authors.lastname: Feng
authors.forename: Jinghai J
authors.initials: JJ
authors.lastname: Xu
authors.forename: Yi-An
authors.initials: YA
authors.lastname: Bi
authors.forename: Rouchelle
authors.initials: R
authors.lastname: Mireles
authors.forename: Ralph
authors.initials: R
authors.lastname: Davidson
authors.forename: David B
authors.initials: DB
authors.lastname: Duignan
authors.forename: Scott
authors.initials: S
authors.lastname: Campbell
authors.forename: Vsevolod E
authors.initials: VE
authors.lastname: Kostrubsky
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Dunn
authors.forename: Arthur R
authors.initials: AR
authors.lastname: Smith
authors.forename: Huifen F
authors.initials: HF
authors.lastname: Wang
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000378:metabolism; D001646:Bile / Q000378:metabolism; D001647:Bile Acids and Salts / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000493:pharmacokinetics* / Q000633:toxicity*; D005452:Fluoresceins / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D008099:Liver / Q000378:metabolism*; D027381:Liver-Specific Organic Anion Transporter 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000187:drug effects; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D011799:Quinazolines / Q000493:pharmacokinetics* / Q000633:toxicity*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors*
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D001647:Bile Acids and Salts; D002118:Calcium; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D005452:Fluoresceins; D027381:Liver-Specific Organic Anion Transporter 1; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; C521104:2-methoxy-N-(3-(4-((3-methyl-4-((6-methyl-3-pyridinyl)oxy)phenyl)amino)-6-quinazolinyl)-2-propenyl)acetamide; C513055:ABCB1 protein, human; C116614:ABCG2 protein, human; C085925:calcein AM; C508053:ERBB2 protein, human