Determinants of gefitinib pharmacokinetics in healthy Chinese male subjects: A pharmacogenomic study of cytochrome p450 enzymes and transporters

Abstract

WHAT IS KNOWN AND OBJECTIVE: Gefitinib, an inhibitor of the epidermal growth factor receptor tyrosine kinase, exhibited a wide interindividual variability in pharmacokinetics. In the present study, we aimed to evaluate the impact of single-nucleotide polymorphisms in the metabolizing enzymes and transporters on gefitinib disposition in healthy Chinese subjects. METHODS: and plasma clearance [CL/F]) and genotypes was evaluated using unpaired t test or Mann-Whitney U test. A stepwise multiple linear regression analysis was applied to assess the relationships between multiple factors and gefitinib pharmacokinetics. Thirty-nine healthy Chinese male subjects were enrolled in the pharmacokinetic study. RESULTS AND DISCUSSION: values (P < .05), respectively, compared to that of subjects carrying wild-type ABCG2 (c.421CC). Additionally, the mean CL/F of the c.421A allele carriers was 32% less than that of the c.421CC carriers (P < .05). No associations were found between polymorphisms in other metabolic enzymes or ABC transporters and gefitinib pharmacokinetics. WHAT IS NEW AND CONCLUSION: Our results suggested that a single-nucleotide polymorphism in ABCG2 (c.421C>A) significantly affected the pharmacokinetics of gefitinib. Further studies are required to evaluate the effects of single-nucleotide polymorphism on the pharmacokinetics, pharmacodynamics and toxicity of gefitinib.