Evaluation of a cost-effective in vitro human model for predicting intrinsic hepatocyte clearance of slowly metabolized compounds

ISSX NA 2023 -- In vitro models play key roles in drug discovery, allowing for the prediction of in vivo metabolism and pharmacokinetics (DMPK) parameters while minimizing cost and maximizing throughput. Primary human hepatocytes (PHH) are often used as a liver model to predict metabolic stability and intrinsic clearance (CLint) of new drug compounds. A drawback of PHH, however, is that standard suspension or plated assays only maintain viability and metabolic activity for up to 4-6 and 72 hours, respectively, which can preclude accurate determination of CLint for slowly metabolized compounds. To extend the incubation window with PHH, we developed a plated 96-well monoculture system capable of maintaining cell morphology and metabolic activity out to two weeks under the hypothesis that this would allow us to assess compounds with extremely low liver clearance ( 1 mL/min/kg). As proof of concept, the metabolism of three drugs with known low clearance - tolbutamide, meloxicam and warfarin - were investigated and the results extrapolated to in vivo hepatic clearance. Additionally, this model was compared to two commercially available kits for cost and accuracy.