Role of P-glycoprotein on the brain penetration and brain pharmacodynamic activity of the MEK inhibitor cobimetinib.
Mol Pharm
; 11(11): 4199-207, 2014 Nov 03.
Article
em En
| MEDLINE
| ID: mdl-25243894
ABSTRACT
Cobimetinib is a MEK inhibitor currently in clinical trials as an anticancer agent. The objectives of this study were to determine in vitro and in vivo if cobimetinib is a substrate of P-glycoprotein (P-gp) and/or breast cancer resistance protein (Bcrp1) and to assess the implications of efflux on cobimetinib pharmacokinetics (PK), brain penetration, and target modulation. Cell lines transfected with P-gp or Bcrp1 established that cobimetinib was a substrate of P-gp but not a substrate of Bcrp1. In vivo, after intravenous and oral administration of cobimetinib to FVB (wild-type; WT), Mdr1a/b(-/-), Bcrp1 (-/-), and Mdr1a/b(-/-)/Bcrp(-/-) knockout (KO) mice, clearance was similar in WT (35.5 ± 16.7 mL/min/kg) and KO animals (22.0 ± 3.6 to 27.6 ± 5.2 mL/min/kg); oral exposure was also similar between WT and KO animals. After an oral 10 mg/kg dose of cobimetinib, the mean total brain to plasma ratio (Kp) at 6 h postdose was 0.3 and 0.2 in WT and Bcrp1(-/-) mice, respectively. In Mdr1a/b(-/-) and Mdr1a/1b/Bcrp1(-/-) KO mice and WT mice treated with elacridar (a P-gp and BCRP inhibitor), Kp increased to 11, 6, and 7, respectively. Increased brain exposure in Mdr1a/b(-/-) and Mdr1a/1b/Bcrp1(-/-) KO and elacridar treated mice was accompanied by up to â¼65% suppression of the target (pErk) in brain tissue, compared to WT mice. By MALDI imaging, the cobimetinib signal intensity was relatively high and was dispersed throughout the brain of Mdr1a/1b/Bcrp1(-/-) KO mice compared to low/undetectable signal intensity in WT mice. The efflux of cobimetinib by P-gp may have implications for the treatment of patients with brain tumors/metastases.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Piperidinas
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Azetidinas
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Encéfalo
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Barreira Hematoencefálica
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Transportadores de Cassetes de Ligação de ATP
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Subfamília B de Transportador de Cassetes de Ligação de ATP
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MAP Quinase Quinase 1
Limite:
Animals
Idioma:
En
Revista:
Mol Pharm
Assunto da revista:
BIOLOGIA MOLECULAR
/
FARMACIA
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FARMACOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos