Department of Pharmacokinetics, Pharmacodynamics and Drug Metabolism (J.Y., R.H., R.K., H.C., L.H., X.C.), and Department of Biometrics Research (S.W., A.L.), Merck & Co., Inc., Kenilworth, New Jersey.
Department of Pharmacokinetics, Pharmacodynamics and Drug Metabolism (J.Y., R.H., R.K., H.C., L.H., X.C.), and Department of Biometrics Research (S.W., A.L.), Merck & Co., Inc., Kenilworth, New Jersey
Drug Metab Dispos. 2022 Jul;50(7):909-922. doi: 10.1124/dmd.121.000807. Epub 2022 Apr 29.
The multidrug resistance protein 1 (MDR1) P-glycoprotein (P-gp) is a clinically important transporter. In vitro P-gp inhibition assays have been routinely conducted to predict the potential for clinical drug-drug interactions (DDIs) mediated by P-gp. However, high interlaboratory and intersystem variability of P-gp IC data limits accurate prediction of DDIs using static models and decision criteria recommended by regulatory agencies. In this study, we calibrated two in vitro P-gp inhibition models: vesicular uptake of N-methyl-quinidine (NMQ) in MDR1 vesicles and bidirectional transport (BDT) of digoxin in Lilly Laboratories Cell Porcine Kidney 1 cells overexpressing MDR1 (LLC-MDR1) using a total of 48 P-gp inhibitor and noninhibitor drugs and digoxin DDI data from 70 clinical studies. Refined thresholds were derived using receiver operating characteristic analysis, and their predictive performance was compared with the decision frameworks proposed by regulatory agencies and selected reference. Furthermore, the impact of various IC calculation methods and nonspecific binding of drugs on DDI prediction was evaluated. Our studies suggest that the concentration of inhibitor based on highest approved dose dissolved in 250 ml divided by IC(I/IC) is sufficient to predict P-gp related intestinal DDIs. IC obtained from vesicular inhibition assay with a refined threshold of I/IC ≥ 25.9 provides comparable predictive power over those measured by net secretory flux and efflux ratio in LLC-MDR1 cells. We therefore recommend vesicular P-gp inhibition as our preferred method given its simplicity, lower variability, higher assay throughput, and more direct estimation of in vitro kinetic parameters, rather than BDT assay. SIGNIFICANCE STATEMENT: This study has conducted comprehensive calibration of two in vitro P-gp inhibition models: uptake in MDR1 vesicles and bidirectional transport in LLC-MDR1 cell monolayers to predict DDIs. This study suggests that ICs obtained from vesicular inhibition with a refined threshold of I/IC ≥ 25.9 provide comparable predictive power over those in LLC-MDR1 cells. Therefore, vesicular P-gp inhibition is recommended as the preferred method given its simplicity, lower variability, higher assay throughput, and more direct estimation of in vitro kinetic parameters.
多药耐药蛋白 1（MDR1）P-糖蛋白（P-gp）是一种具有临床重要意义的转运蛋白。体外 P-gp 抑制试验已常规用于预测由 P-gp 介导的临床药物相互作用（DDI）的潜力。然而，由于 P-gpIC 数据在不同实验室和系统之间存在高度变异性，因此使用监管机构推荐的静态模型和决策标准准确预测 DDI 受到限制。在这项研究中，我们使用总共 48 种 P-gp 抑制剂和非抑制剂药物以及来自 70 项临床研究的地高辛 DDI 数据，对两种体外 P-gp 抑制模型进行了校准：MDR1 囊泡中的 N-甲基喹啉（NMQ）囊泡摄取和 Lilly 实验室细胞猪肾 1 细胞（LLC-MDR1）中的地高辛双向转运（BDT）。使用接收器操作特征分析得出了改进的阈值，并将其预测性能与监管机构提出的决策框架和选定的参考进行了比较。此外，还评估了不同 IC 计算方法和药物非特异性结合对 DDI 预测的影响。我们的研究表明，基于最高批准剂量溶解在 250ml 中的抑制剂浓度除以 IC（I/IC）足以预测与 P-gp 相关的肠道 DDI。IC 是从囊泡抑制试验中获得的，其改进的阈值为 I/IC≥25.9，与在 LLC-MDR1 细胞中通过净分泌通量和外排比测量的 IC 具有相当的预测能力。因此，我们建议使用囊泡 P-gp 抑制作为首选方法，因为它简单、变异性低、检测通量高，并且更直接估计体外动力学参数，而不是 BDT 检测。
本研究对两种体外 P-gp 抑制模型：MDR1 囊泡摄取和 LLC-MDR1 细胞单层双向转运进行了全面校准，以预测 DDI。本研究表明，用改进的 I/IC≥25.9 阈值从囊泡抑制获得的 IC 提供了与在 LLC-MDR1 细胞中获得的 IC 相当的预测能力。因此，由于其简单性、低变异性、高检测通量和更直接估计体外动力学参数，因此建议使用囊泡 P-gp 抑制作为首选方法。
