Yan Zhang1, Changyuan Wang2, Zhihao Liu2, Qiang Meng2, Xiaokui Huo2, Qi Liu2, Pengyuan Sun2, Xiaobo Yang2, Huijun Sun2, Xiaodong Ma2, Kexin Liu3. 1. Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, China; Peking University Third Hospital Yanqing Hospital, Beijing, China. 2. Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, China; Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, China. 3. Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, China; Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, China. Electronic address: kexinliu@dlmedu.edu.cn.
Abstract
BACKGROUND: Afatinib is an irreversible multi-targeted TKI, used in the treatment with EGFR mutated non-small cell lung cancer (NSCLC). The purpose of this study is to explore the molecular pharmacokinetic mechanism underlying the effect of P-gp inhibitors on the intestinal absorption and biliary excretion and to understand how P-gp inhibitors affect afatinib pharmacokinetics. METHODS: Pharmacokinetics in vivo, in situ intestinal perfusion, perfused rat liver in situ, Caco-2 cells, P-gp ATPase activity, sandwich-cultured rat hepatocytes (SCRH) and transfected-cell transport were used in the evaluation. RESULTS: P-gp inhibitor verapamil (Ver) markedly increased the plasma concentrations and significantly decreased the biliary excretion of afatinib in vivo. Ver increased the intestinal absorption and decreased biliary excretion of afatinib in situ single-pass intestinal perfusion studies and in situ perfused rat liver, respectively. The accumulation of afatinib in Caco-2 cells was enhanced by Ver and Cyclosporin A (CsA). The biliary excretion index (BEI) of afatinib in SCRH was decreased by Ver and CsA, respectively. The net efflux ratio of afatinib was 2.3 across vector-/MDR1-MDCKII cell monolayers and was decreased by P-gp inhibitor. The activity of P-gp ATPase was induced by afatinib and the Km and Vmax were 1.05μM and 59.88nmol ATP/mg hP-gp/min, respectively. CONCLUSION: At least partly P-gp is involved in increasing the intestinal absorption and decreasing the biliary excretion of afatinib in rats.
BACKGROUND:Afatinib is an irreversible multi-targeted TKI, used in the treatment with EGFR mutated non-small cell lung cancer (NSCLC). The purpose of this study is to explore the molecular pharmacokinetic mechanism underlying the effect of P-gp inhibitors on the intestinal absorption and biliary excretion and to understand how P-gp inhibitors affect afatinib pharmacokinetics. METHODS: Pharmacokinetics in vivo, in situ intestinal perfusion, perfused rat liver in situ, Caco-2 cells, P-gp ATPase activity, sandwich-cultured rat hepatocytes (SCRH) and transfected-cell transport were used in the evaluation. RESULTS:P-gp inhibitor verapamil (Ver) markedly increased the plasma concentrations and significantly decreased the biliary excretion of afatinib in vivo. Ver increased the intestinal absorption and decreased biliary excretion of afatinib in situ single-pass intestinal perfusion studies and in situ perfused rat liver, respectively. The accumulation of afatinib in Caco-2 cells was enhanced by Ver and Cyclosporin A (CsA). The biliary excretion index (BEI) of afatinib in SCRH was decreased by Ver and CsA, respectively. The net efflux ratio of afatinib was 2.3 across vector-/MDR1-MDCKII cell monolayers and was decreased by P-gp inhibitor. The activity of P-gp ATPase was induced by afatinib and the Km and Vmax were 1.05μM and 59.88nmol ATP/mg hP-gp/min, respectively. CONCLUSION: At least partly P-gp is involved in increasing the intestinal absorption and decreasing the biliary excretion of afatinib in rats.