title: Increased oral availability and brain accumulation of the ALK inhibitor crizotinib by coadministration of the P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) inhibitor elacridar.
abstract: Crizotinib is an oral tyrosine kinase inhibitor approved for treating patients with non-small cell lung cancer (NSCLC) containing an anaplastic lymphoma kinase (ALK) rearrangement. We used knockout mice to study the roles of P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) in plasma pharmacokinetics and brain accumulation of oral crizotinib, and the feasibility of improving crizotinib kinetics using coadministration of the dual ABCB1/ABCG2 inhibitor elacridar. In vitro, crizotinib was a good transport substrate of human ABCB1, but not of human ABCG2 or murine Abcg2. With low-dose oral crizotinib (5 mg/kg), Abcb1a/1b(-/-) and Abcb1a/1b;Abcg2(-/-) mice had an approximately twofold higher plasma AUC than wild-type mice, and a markedly (~40-fold) higher brain accumulation at 24 hr. Also at 4 hr, crizotinib brain concentrations were ∼25-fold, and brain-to-plasma ratios ~14-fold higher in Abcb1a/1b(-/-) and Abcb1a/1b;Abcg2(-/-) mice than in wild-type mice. High-dose oral crizotinib (50 mg/kg) resulted in comparable plasma pharmacokinetics between wild-type and Abcb1a/1b(-/-) mice, suggesting saturation of intestinal Abcb1. Nonetheless, brain accumulation at 24 hr was still ~70-fold higher in Abcb1a/1b(-/-) than in wild-type mice. Importantly, oral elacridar coadministration increased the plasma and brain concentrations and brain-to-plasma ratios of crizotinib in wild-type mice, equaling the levels in Abcb1a/1b;Abcg2(-/-) mice. Our results indicate that crizotinib oral availability and brain accumulation were primarily restricted by Abcb1 at a non-saturating dose, and that coadministration of elacridar with crizotinib could substantially increase crizotinib oral availability and delivery to the brain. This principle might be used to enhance therapeutic efficacy of crizotinib against brain metastases in NSCLC patients.
authors.affiliation: Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Seng Chuan
authors.initials: SC
authors.lastname: Tang
authors.forename: Luan N
authors.initials: LN
authors.lastname: Nguyen
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Sparidans
authors.forename: Els
authors.initials: E
authors.lastname: Wagenaar
authors.forename: Jos H
authors.initials: JH
authors.lastname: Beijnen
authors.forename: Alfred H
authors.initials: AH
authors.lastname: Schinkel
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D000166:Acridines / Q000494:pharmacology*; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D000077547:Crizotinib; D004359:Drug Therapy, Combination; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000493:pharmacokinetics / Q000494:pharmacology*; D011720:Pyrazoles / Q000493:pharmacokinetics / Q000494:pharmacology*; D011725:Pyridines / Q000493:pharmacokinetics / Q000494:pharmacology*; D044005:Tetrahydroisoquinolines / Q000494:pharmacology*; D014018:Tissue Distribution
chemical_list: C513055:ABCB1 protein, human; C116614:ABCG2 protein, human; 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; C501412:Abcg2 protein, mouse; D000166:Acridines; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011725:Pyridines; D044005:Tetrahydroisoquinolines; D000077547:Crizotinib; C083501:Elacridar
keywords: ALK inhibitor; P-glycoprotein; brain accumulation; crizotinib; elacridar