PT - JOURNAL ARTICLE AU - Lifei Wang AU - Donglu Zhang AU - Nirmala Raghavan AU - Ming Yao AU - Li Ma AU - Charles A. Frost AU - Brad D. Maxwell AU - Shiang-yuan Chen AU - Kan He AU - Theunis C. Goosen AU - W. Humphreys Griffith AU - Scott J. Grossman TI - In Vitro Assessment of Metabolic Drug-Drug Interaction Potential of Apixaban through Cytochrome P450 Phenotyping, Inhibition, and Induction Studies AID - 10.1124/dmd.109.029694 DP - 2010 Mar 01 TA - Drug Metabolism and Disposition PG - 448--458 VI - 38 IP - 3 4099 - http://dmd.aspetjournals.org/content/38/3/448.short 4100 - http://dmd.aspetjournals.org/content/38/3/448.full SO - Drug Metab Dispos2010 Mar 01; 38 AB - Apixaban is an oral, direct, and highly selective factor Xa inhibitor in late-stage clinical development for the prevention and treatment of thromboembolic diseases. The metabolic drug-drug interaction potential of apixaban was evaluated in vitro. The compound did not show cytochrome P450 inhibition (IC50 values >20 μM) in incubations of human liver microsomes with the probe substrates of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4/5. Apixaban did not show any effect at concentrations up to 20 μM on enzyme activities or mRNA levels of selected P450 enzymes (CYP1A2, 2B6, and 3A4/5) that are sensitive to induction in incubations with primary human hepatocytes. Apixaban showed a slow metabolic turnover in incubations of human liver microsomes with formation of O-demethylation (M2) and hydroxylation products (M4 and M7) as prominent in vitro metabolites. Experiments with human cDNA-expressed P450 enzymes and P450 chemical inhibitors and correlation with P450 activities in individual human liver microsomes demonstrated that the oxidative metabolism of apixaban for formation of all metabolites was predominantly catalyzed by CYP3A4/5 with a minor contribution of CYP1A2 and CYP2J2 for formation of M2. The contribution of CYP2C8, 2C9, and 2C19 to metabolism of apixaban was less significant. In addition, a human absorption, distribution, metabolism, and excretion study showed that more than half of the dose was excreted as unchanged parent (fm CYP <0.5), thus significantly reducing the overall metabolic drug-drug interaction potential of apixaban. Together with a low clinical efficacious concentration and multiple clearance pathways, these results demonstrate that the metabolic drug-drug interaction potential between apixaban and coadministered drugs is low. Copyright © 2010 by The American Society for Pharmacology and Experimental Therapeutics