title: An unexpected synergist role of P-glycoprotein and breast cancer resistance protein on the central nervous system penetration of the tyrosine kinase inhibitor lapatinib (N-{3-chloro-4-[(3-fluorobenzyl)oxy]phenyl}-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furyl]-4-quinazolinamine; GW572016).
abstract: Lapatinib is a tyrosine kinase inhibitor approved for use in combination with capecitabine to treat advanced or metastatic breast cancers overexpressing human epidermal receptor 2 (ErbB2). This work investigated the role of P-glycoprotein (Pgp; the protein from the Mdr1a/b gene) and breast cancer resistance protein (Bcrp; the protein from the Bcrp1 gene) in modulating the central nervous system penetration of lapatinib at steady-state conditions in FVBn mice (wild-type), Mdr1a/b(-/-), Bcrp1(-/-), and Mdr1a/b(-/-)/Bcrp1(-/-) knockout mice. After an intravenous infusion of lapatinib for 24 h to a targeted steady-state plasma concentration of 700 ng/ml (0.3 mg/kg/h) or 7000 ng/ml (3 mg/kg/h), lapatinib brain-to-plasma ratios were approximately 3- to 4-fold higher in Mdr1a/b(-/-) knockout mice (ratio range from 0.09 to 0.16) compared with wild-type mice (ratio range from 0.03 to 0.04). There was no difference in the brain-to-plasma ratio in the Bcrp1(-/-) knockout mice (ratio range from 0.03 to 0.04) compared with wild-type mice. In contrast, Mdr1a/b(-/-)/Bcrp1(-/-) triple knockout mice had a 40-fold higher brain-to-plasma ratio (ratio range from 1.2 to 1.7), suggesting that Pgp and Bcrp work in concert to limit the brain-to-plasma ratio of lapatinib in mice. This finding has important potential consequences for the treatment of brain tumors in breast cancer patients treated with tyrosine kinase inhibitors as well as the basic understanding of ATP binding cassette transporters expressed in the blood-brain barrier on the central nervous system disposition of drugs.
authors.affiliation: Preclinical Drug Metabolism and Pharmacokinetics, GlaxoSmithKline, Inc., P.O. Box 13398, Room MAI.A2213, Research Triangle Park, NC 27709, USA. joseph.w.polli@gsk.com
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Polli
authors.forename: Katie L
authors.initials: KL
authors.lastname: Olson
authors.forename: John P
authors.initials: JP
authors.lastname: Chism
authors.forename: Lisa St
authors.initials: LS
authors.lastname: John-Williams
authors.forename: Russell L
authors.initials: RL
authors.lastname: Yeager
authors.forename: Sesha M
authors.initials: SM
authors.lastname: Woodard
authors.forename: Vicky
authors.initials: V
authors.lastname: Otto
authors.forename: Stephen
authors.initials: S
authors.lastname: Castellino
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Demby
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D019540:Area Under Curve; D001692:Biological Transport / Q000187:drug effects* / Q000502:physiology; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism; D002490:Central Nervous System / Q000187:drug effects* / Q000378:metabolism; D006224:Cricetinae; D004195:Disease Models, Animal; D004357:Drug Synergism; D005260:Female; D006801:Humans; D000077341:Lapatinib; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011799:Quinazolines / Q000737:chemistry / Q000494:pharmacology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D000077341:Lapatinib; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; C524056:Erbb2 protein, mouse