Table 1.

Brain-to-Plasma Ratio of Various P-gp and BCRP Substrate Chemotherapeutic Agents for the Treatment of Brain Metastases

Chemotherapeutic Agent	Cancer Type	Molecular Target	Clinical Status	Substrate		Brain-to-Plasma Ratio	Reference
				P-gp	BCRP
Vemurafenib	Melanoma	Mutant BRAF	Approved	Yes	Yes	1.00 ± 0.19	112, 113
Dabrafenib	Melanoma, non–small-cell lung cancer, and thyroid cancer	Mutant BRAF	Approved	Yes	Yes	0.25	114
Trametinib	Melanoma, non–small-cell lung cancer, and thyroid cancer	MEK	Approved	Yes	No	2.45 ± 1.3	115
Cobimetinib	Melanoma	MEK	Approved	Yes	No	1.1, 6.2	116
Palbociclib	Breast cancer	CDK4/6	Approved	Yes	Yes	28 ± 6	117
Doxorubicin	Breast cancer, leukemia, lymphoma, ovarian cancer, neuroblastoma, bone cancer, and thyroid cancer	Topoisomerase II	Approved	Yes	Yes	0.0014	118
Paclitaxel	Breast cancer, lung cancer, ovarian cancer, and Kaposi’s sarcoma	Tubulin beta-1 chain, apoptosis regulator Bcl-2	Approved	Yes	No	<3%	17,106