The impact of P-glycoprotein and breast cancer resistance protein on the brain pharmacokinetics and pharmacodynamics of a panel of MEK inhibitors.

Abstract

Mitogen/extracellular signal-regulated kinase (MEK) inhibitors have been tested in clinical trials for treatment of intracranial neoplasms, including glioblastoma (GBM), but efficacy of these drugs has not yet been demonstrated. The blood-brain barrier (BBB) is a major impediment to adequate delivery of drugs into the brain and may thereby also limit the successful implementation of MEK inhibitors against intracranial malignancies. The BBB is equipped with a range of ATP-dependent efflux transport proteins, of which P-gp (ABCB1) and BCRP (ABCG2) are the two most dominant for drug efflux from the brain. We investigated their impact on the pharmacokinetics and target engagement of a panel of clinically applied MEK inhibitors, in order to select the most promising candidate for brain cancers in the context of clinical pharmacokinetics and inhibitor characteristics. To this end, we used in vitro drug transport assays and conducted pharmacokinetic and pharmacodynamic studies in wildtype and ABC-transporter knockout mice. PD0325901 displayed more promising characteristics than trametinib (GSK1120212), binimetinib (MEK162), selumetinib (AZD6244), and pimasertib (AS703026): PD0325901 was the weakest substrate of P-gp and BCRP in vitro, its brain penetration was only marginally higher in Abcb1a/b;Abcg2-/- mice, and efficient target inhibition in the brain could be achieved at clinically relevant plasma levels. Notably, target inhibition could also be demonstrated for selumetinib, but only at plasma levels far above levels in patients receiving the maximum tolerated dose. In summary, our study recommends further development of PD0325901 for the treatment of intracranial neoplasms.

• Authors: Mark C de Gooijer, Ping Zhang, Ruud Weijer, Levi C M Buil, Jos H Beijnen, Olaf van Tellingen
• Journal: International journal of cancer (Int J Cancer) Vol. 142 Issue 2 Pg. 381-391 (01 15 2018) ISSN: 1097-0215 [Electronic] United States
• PMID: 28921565 (Publication Type: Journal Article)
• Copyright: © 2017 UICC.

Chemical References

• ATP Binding Cassette Transporter, Subfamily B
• ATP Binding Cassette Transporter, Subfamily G, Member 2
• Abcg2 protein, mouse
• Protein Kinase Inhibitors
• multidrug resistance protein 3
• MAP Kinase Kinase 1
• Abcb1b protein, mouse

Topics

• ATP Binding Cassette Transporter, Subfamily B (physiology)
• ATP Binding Cassette Transporter, Subfamily G, Member 2 (physiology)
• Animals
• Blood-Brain Barrier (drug effects, metabolism)
• Brain (drug effects, metabolism)
• MAP Kinase Kinase 1 (antagonists & inhibitors)
• Mice
• Mice, Knockout
• Protein Kinase Inhibitors (pharmacokinetics, pharmacology)
• Tissue Distribution