TY - JOUR T1 - <strong>OATP1B1/1B3</strong><strong>-mediated hepatic uptake determines the pharmacokinetics of large lipophilic acids</strong><strong>: In vitro-in vivo evaluation in cynomolgus monkey</strong> JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther DO - 10.1124/jpet.120.000457 SP - JPET-AR-2020-000457 AU - Heather Eng AU - Yi-an Bi AU - Mark A. West AU - Sangwoo Ryu AU - Emi Yamaguchi AU - Rachel E. Kosa AU - David A. Tess AU - David A. Griffith AU - John E. Litchfield AU - Amit S. Kalgutkar AU - Manthena V. S. Varma Y1 - 2021/01/01 UR - http://jpet.aspetjournals.org/content/early/2021/01/27/jpet.120.000457.abstract N2 - It is generally presumed that uptake transport mechanisms are of limited significance in hepatic clearance for lipophilic or high passive permeability drugs. In this study, we evaluated the mechanistic role of the hepato-selective organic anion transporting polypeptides (OATP1B1/1B3) in the pharmacokinetics of compounds representing large lipophilic acid space. Intravenous pharmacokinetics of 16 compounds, with molecular weight ~400-730 Da, logP ~3.5-8 and acid pKa &lt;6, were obtained in cynomolgus monkey following dosing without and with a single-dose rifampicin-OATP1B1/1B3 probe inhibitor. Rifampicin (30 mg/kg oral) significantly (p&lt;0.05) reduced monkey clearance and/or volume of distribution (VDss) for 15 of 16 acids evaluated. Additionally, clearance of danoprevir was reduced by about 35%, although statistical significance was not reached. A significant linear relationship was noted between the clearance ratio (i.e., ratio of control to treatment groups) and VDss ratio, suggesting hepatic uptake contributes to the systemic clearance and distribution simultaneously. In vitro transport studies using primary monkey and human hepatocytes showed uptake inhibition by rifampicin (100 µM) for compounds with logP{less than or equal to}6.5, but not for the very lipophilic acids (logP&gt;6.5), which generally showed high non-specific binding in hepatocyte incubations. In vitro uptake clearance and fraction transported by OATP1B1/1B3 (ft,OATP1B) were found to be similar in monkey and human hepatocytes. Finally, for compounds with logP{less than or equal to}6.5, good agreement was noted between in vitro ft,OATP1B and clearance ratio (and VDss ratio) in cynomolgus monkey. In conclusion, this study provides mechanistic evidence for the pivotal role of OATP1B-mediated hepatic uptake in the pharmacokinetics across a wide large lipophilic acid space. Significance Statement Our study provides mechanistic insight into the pharmacokinetics of a broad range of large lipophilic acids. OATP1B1/1B3-mediated hepatic uptake is of key importance in the pharmacokinetics and drug-drug interactions of almost all drugs and new molecular entities in this space. Diligent in vitro and in vivo transport characterization is needed to avoid the false negatives often noted due to general limitations in the in vitro assays while handling compounds with such physicochemical attributes. ER -