Afatinib pharmacokinetics and metabolism after oral administration to healthy male volunteers

作者:Stopfer Peter*; Marzin Kristell; Narjes Hans; Gansser Dietmar; Shahidi Mehdi; Uttereuther Fischer Martina; Ebner Thomas
来源:Cancer Chemotherapy and Pharmacology, 2012, 69(4): 1051-1061.
DOI:10.1007/s00280-011-1803-9

摘要

Purpose To investigate the pharmacokinetics, metabolism and tolerability of afatinib (BIBW 2992), an oral irreversible ErbB family blocker, in healthy male volunteers. Methods In this open-label, single-center study, 8 healthy male volunteers received a single oral dose of 15 mg [C-14]radiolabeled afatinib (equivalent to 22.2 mg of the dimaleinate salt) as a solution. Blood, urine and fecal samples were collected for at least 96 hours (h) after dosing. Plasma and urine concentrations of afatinib were analyzed using high-performance liquid chromatography-tandem mass spectrometry.[C-14]-radioactivity levels in plasma, whole blood, urine and feces were measured by liquid scintillation counting methods. Metabolite patterns were assessed by high-performance liquid chromatography. Results [C-14]-radioactivity was mainly excreted via feces (85.4%). Overall recovery of [C-14]-radioactivity was 89.5%, indicative of a complete mass balance. Afatinib was slowly absorbed, with maximum plasma concentrations achieved at a median of 6 h after dosing, declining thereafter in a biexponential manner. The geometric mean terminal half-life of afatinib was 33.9 h in plasma and longer for [C-14]-radioactivity in plasma and whole blood. Apparent total body clearance for afatinib was high (geometric mean 1,530 mL/min). The high volume of distribution (4,500 L) in plasma may indicate a high tissue distribution. Afatinib was metabolized to only a minor extent, with the main metabolite afatinib covalently bound to plasma proteins. Oxidative metabolism mediated via cytochrome P-450 was of negligible importance for the elimination of afatinib. Afatinib was well tolerated. Conclusions Afatinib displayed a complete mass balance with the main route of excretion via feces. Afatinib undergoes minimal metabolism.

  • 出版日期2012-4