Evaluation of Normalization Methods To Predict CYP3A4 Induction in Six Fully Characterized Cryopreserved Human Hepatocyte Preparations and HepaRG Cells

Abstract

Prediction of drug-drug interactions due to cytochrome P450 isoform 3A4 (CYP3A4) overexpression is important because this CYP isoform is involved in the metabolism of about 30% of clinically used drugs from almost all therapeutic categories. Therefore, it is mandatory to attempt to predict the potential of a new compound to induce CYP3A4. Among several in vitro-in vivo extrapolation methods recently proposed in the literature, an approach using a scaling factor, called a d factor, for a given hepatocyte batch to provide extrapolation between in vitro induction data and clinical outcome has been adopted by leading health authorities. We challenged the relevance of the calibration factor determined using a set of 15 well-known clinical CYP3A4 inducers or the potent CYP3A4 inducer rifampicin only. These investigations were conducted using six batches of human hepatocytes and an established HepaRG cell line. Our findings show that use of a calibration factor is preferable for clinical predictions, as shown previously by other investigators. Moreover, the present results also suggest that the accuracy of prediction through calculation of this factor is sufficient when rifampicin is considered alone, and the use of a larger set of fully characterized CYP3A4 clinical inducers is not required. For the established HepaRG cell line, the findings obtained in three experiments using a single batch of cells show a good prediction accuracy with or without the d factor. Additional investigations with different batches of HepaRG cell lines are needed to confirm these results.

Evaluation of a novel PXR‐knockout in HepaRG™ cells

“…Lower basal gene expression in HepaRG WT and 5F cells found were in agreement with previous work (Rogue et al 2012). Following treatment with prototypical inducers, HepaRG cells provided E max and EC 50 values similar to those reported previously (Tables 2, 3) (Grime et al 2010;Vermet et al 2016). Likewise, the induced mRNA data were in agreement with effects observed at the enzymatic level ( Fig.…”

“…Recent work has demonstrated HepaRG variability between experiments is particularly low (Vermet et al. ), which is further confirmed with alternative HepaRG batches used herein. Similarly, E max values between PHH donors varied considerably (Tables ), whereas a low interexperiment variability was observed for HepaRG cells.…”

“…Advances in in vitro analysis aim to efficiently represent human donors as well as reducing the variability observed between laboratories and experiments. Recent work has demonstrated HepaRG variability between experiments is particularly low (Vermet et al 2016), which is further confirmed with alternative HepaRG batches used herein. Similarly, E max values between PHH donors varied considerably (Tables 2, 3), whereas a low interexperiment variability was observed for HepaRG cells.…”

“…; Vermet et al. ). Likewise, the induced mRNA data were in agreement with effects observed at the enzymatic level (Fig.…”

Managing the Risk of CYP3A Induction in Drug Development: A Strategic Approach

“…A further 23 AZ compounds with unknown induction potential and a variety of therapeutic targets and molecular structures have since been studied in both HepaRG cells and human hepatocytes (two or three donors per compound) and support the conclusion that HepaRG cells and primary human hepatocytes respond correspondingly to new chemical series (see the Supplemental Material) . A recent study by Vermet et al (2016) further supports this conclusion with a set of 15 well-known clinical CYP3A4 inducers comparing HepaRG with six batches of primary human hepatocytes (Vermet et al, 2016).…”