Characterization of Hepatocytes Uptake Clearance of Organic Anion Transporting Polypeptide (OATPs) Substrates in Human and Cynomolgus Cryopreserved Hepatocytes

Abstract

Transporter‐mediated clearance plays significant roles in drug bioavailability and elimination, and evaluation of potential transporter‐mediated drug‐drug interactions (DDI) is recommended by regulatory agencies during drug development. Currently, the direct extrapolation from in vitro to in vivo is a common approach for human clearance prediction for the compounds that are metabolized by hepatic cytochrome P450 enzymes; however, challenge remains when using the similar approaches in prediction of transporter‐mediated clearance. Recent publications attempted to establish the in‐vitro‐to‐ in vivo scaling based on hepatocyte uptake studies and in vivo pharmacokinetic (PK) data from the preclinical animals. However, the differences in homology of transporter proteins and the associated substrate specificity in transporters between human and preclinical animals complicate the prediction using the correcting factors obtained from the preclinical animals' in‐vitro‐to‐ in vivo scaling. In this study, we obtained the in vitro hepatic uptake clearance in cynomolgus monkey and human for 14 literature compounds that were known as OATPs substrates and had clinical DDI reported. Hepatic uptake was conducted using the oil‐spin method. For each selected substrate, the uptake assay was conducted in the time course from 0.25 minute to 15 minutes in KHB buffer with 10% serum. The uptake clearance was estimated from the linear uptake phase. For each selected substrate, the uptake clearance was characterized in three lots (including single donor and pooled donors lots) of human and monkey cryopreserved hepatocytes. In addition, we tested different lots of human (7 lots) and monkey (10 lots) cryopreserved hepatocytes using rosuvastatin as a control probe to examine the variability among lots and donors. In summary, rosuvastatin uptake clearance in cynomolgus monkey hepatocytes was about 2.5 folds higher on average compared to that in human hepatocytes. Generally, for other OATPs substrates studied, hepatic uptake clearance in cynomolgus monkey appeared to be higher than that in human. Furthermore, variability of uptake clearance was also observed among lots and donors. The results obtained in the current investigations are useful for human prediction through understanding the source of variations and establishing the correlations of in vitro‐in vivo scaling.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.