PT  - JOURNAL ARTICLE
AU  - Kim, Sean
AU  - Dinchuk, Joseph E.
AU  - Anthony, Monique N.
AU  - Orcutt, Tami
AU  - Zoeckler, Mary E.
AU  - Sauer, Mary B.
AU  - Mosure, Kathleen W.
AU  - Vuppugalla, Ragini
AU  - Grace, James E.
AU  - Simmermacher, Jean
AU  - Dulac, Heidi A.
AU  - Pizzano, Jennifer
AU  - Sinz, Michael
TI  - Evaluation of Cynomolgus Monkey Pregnane X Receptor, Primary Hepatocyte, and in Vivo Pharmacokinetic Changes in Predicting Human CYP3A4 Induction
AID  - 10.1124/dmd.109.029637
DP  - 2010 Jan 01
TA  - Drug Metabolism and Disposition
PG  - 16--24
VI  - 38
IP  - 1
4099  - http://dmd.aspetjournals.org/content/38/1/16.short
4100  - http://dmd.aspetjournals.org/content/38/1/16.full
SO  - Drug Metab Dispos2010 Jan 01; 38
AB  - Monkeys have been proposed as an animal model to predict the magnitude of human clinical drug-drug interactions caused by CYP3A4 enzyme induction. To evaluate whether the cynomolgus monkey can be an effective in vivo model, human CYP3A4 inducers were evaluated both in vitro and in vivo. First, a full-length pregnane X receptor (PXR) was cloned from the cynomolgus monkey, and the sequence was compared with those of rhesus monkey and human PXR. Cynomolgus and rhesus monkey PXR differed by only one amino acid (A68V), and both were highly homologous to human PXR (∼96%). When the transactivation profiles of 30 compounds, including known inducers of CYP3A4, were compared between cynomolgus and human PXR, a high degree of correlation with EC50 values was observed. These results suggest that cynomolgus and human PXR respond in a similar fashion to these ligands. Second, two known human CYP3A4 inducers, rifampicin and hyperforin, were tested in monkey and human primary hepatocytes for induction of CYP3A enzymes. Both monkey and human hepatocytes responded similarly to the inducers and resulted in increased RNA and enzyme activity changes of CYP3A8 and CYP3A4, respectively. Lastly, in vivo induction of CYP3A8 by rifampicin and hyperforin was shown by significant reductions of midazolam exposure that were comparable with those in humans. These results show that the cynomolgus monkey can be a predictive in vivo animal model of PXR-mediated induction of human CYP3A4 and can provide a useful assessment of the resulting pharmacokinetic changes of affected drugs. Copyright © 2010 by The American Society for Pharmacology and Experimental Therapeutics