Format

Send to

Choose Destination
J Nucl Med. 2017 Jan;58(1):117-122. doi: 10.2967/jnumed.116.178665. Epub 2016 Aug 4.

Strategies to Inhibit ABCB1- and ABCG2-Mediated Efflux Transport of Erlotinib at the Blood-Brain Barrier: A PET Study on Nonhuman Primates.

Author information

1
Imagerie Moléculaire In Vivo, IMIV, CEA, INSERM, CNRS, Université Paris-Sud, Université Paris Saclay, CEA-SHFJ, Orsay, France nicolas.tournier@cea.fr.
2
Imagerie Moléculaire In Vivo, IMIV, CEA, INSERM, CNRS, Université Paris-Sud, Université Paris Saclay, CEA-SHFJ, Orsay, France.
3
Health and Environment Department, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria.
4
Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria; and.
5
Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.

Abstract

The tyrosine kinase inhibitor erlotinib poorly penetrates the blood-brain barrier (BBB) because of efflux transport by P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2), thereby limiting its utility in the treatment of non-small cell lung cancer metastases in the brain. Pharmacologic strategies to inhibit ABCB1/ABCG2-mediated efflux transport at the BBB have been successfully developed in rodents, but it remains unclear whether these can be translated to humans given the pronounced species differences in ABCG2/ABCB1 expression ratios at the BBB. We assessed the efficacy of two different ABCB1/ABCG2 inhibitors to enhance brain distribution of 11C-erlotinib in nonhuman primates as a model of the human BBB.

METHODS:

Papio anubis baboons underwent PET scans of the brain after intravenous injection of 11C-erlotinib under baseline conditions (n = 4) and during intravenous infusion of high-dose erlotinib (10 mg/kg/h, n = 4) or elacridar (12 mg/kg/h, n = 3).

RESULTS:

Under baseline conditions, 11C-erlotinib distribution to the brain (total volume of distribution [VT], 0.22 ± 0.015 mL/cm3) was markedly lower than its distribution to muscle tissue surrounding the skull (VT, 0.86 ± 0.10 mL/cm3). Elacridar infusion resulted in a 3.5 ± 0.9-fold increase in 11C-erlotinib distribution to the brain (VT, 0.81 ± 0.21 mL/cm3, P < 0.01), reaching levels comparable to those in muscle tissue, without changing 11C-erlotinib plasma pharmacokinetics. During high-dose erlotinib infusion, 11C-erlotinib brain distribution was also significantly (1.7 ± 0.2-fold) increased (VT, 0.38 ± 0.033 mL/cm3, P < 0.05), with a concomitant increase in 11C-erlotinib plasma exposure.

CONCLUSION:

We successfully implemented ABCB1/ABCG2 inhibition protocols in nonhuman primates resulting in pronounced increases in brain distribution of 11C-erlotinib. For patients with brain tumors, such inhibition protocols may ultimately be applied to create more effective treatments using drugs that undergo efflux transport at the BBB.

KEYWORDS:

P-glycoprotein; blood–brain barrier; brain metastasis; breast cancer resistance protein; erlotinib

PMID:
27493269
DOI:
10.2967/jnumed.116.178665
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center