Analysis of in vitro- to-in vivo predictions of transporter-mediated inhibition drug interactions for drugs approved by the USA Food and Drug Administration between 2013 and 2016

Presented at Asia Pacific ISSX conference, May 2018, Hangzhou City, China
Jingjing Yu and Isabelle Ragueneau-Majlessi

2018 Asia Pacific ISSX Poster Presentation – Transporter-mediated DDIs


The present work aimed to systematically review transporter-based in vitro and clinical inhibition evaluations of drugs approved by the U.S. Food and Drug Administration (FDA) from 2013 to 2016. In vitro inhibition parameters, pharmacokinetics, and clinical drug-drug interaction (DDI) studies available in the New Drug Application (NDA) reviews were analyzed using the University of Washington Drug Interaction Database. Following recommendations from the 2012 FDA DDI guidance, in vitro to in vivo prediction estimates were calculated for the transporters the most often studied.

Risk of Clinically Relevant Pharmacokinetic-Based Drug-Drug Interactions with Drugs Approved by the U.S. Food and Drug Administration Between 2013 and 2016

Drug Metab Dispos. 2018 Jun; 46(6): 835-845.
Published online 2018 Mar 23


A total of 103 drugs (including 14 combination drugs) were approved by the U.S. Food and Drug Administration from 2013 to 2016. Pharmacokinetic-based drug interaction profiles were analyzed using the University of Washington Drug Interaction Database, and the clinical relevance of these observations was characterized based on information from new drug application reviews. CYP3A was involved in approximately two-thirds of all drug-drug interactions (DDIs). Transporters (alone or with enzymes) participated in about half of all interactions, but most of these were weak-to-moderate interactions. When considered as victims, eight new molecular entities (NMEs; cobimetinib, ibrutinib, isavuconazole, ivabradine, naloxegol, paritaprevir, simeprevir, and venetoclax) were identified as sensitive substrates of CYP3A, two NMEs (pirfenidone and tasimelteon) were sensitive substrates of CYP1A2, one NME (dasabuvir) was a sensitive substrate of CYP2C8, one NME (eliglustat) was a sensitive substrate of CYP2D6, and one NME (grazoprevir) was a sensitive substrate of OATP1B1/3 (with changes in exposure greater than 5-fold when coadministered with a strong inhibitor). Approximately 75% of identified CYP3A substrates were also substrates of P-glycoprotein. As perpetrators, most clinical DDIs involved weak-to-moderate inhibition or induction. Only idelalisib showed strong inhibition of CYP3A, and lumacaftor behaved as a strong CYP3A inducer. Among drugs with large changes in exposure (≥5-fold), whether as victim or perpetrator, the most-represented therapeutic classes were antivirals and oncology drugs, suggesting a significant risk of clinical DDIs in these patient populations.

Identification and evaluation of clinical substrates of organic anion transporting polypeptides 1B1 and 1B3

Presented at ISSX conference, September 2017, Providence, RI, USA
Savannah J. McFeely, Yu, Tasha K. Ritchie, Jingjing Yu, Eva Gil Berglund, Anna Nordmark, and Isabelle Ragueneau-Majlessi

2017 ISSX Poster Presentation – Evaluation of Clinical Substrates of OATP1B1/3


The aim of this work was twofold: i) Provide a thorough analysis of the available in vitro and in vivo data regarding OATP1B1/1B3 substrates, ii)Propose the most sensitive and selective probe markers of OATP1B1/1B3 activity.

Understanding the risk of clinically significant pharmacokinetic-based drug-drug interactions with drugs newly approved by the US FDA – a review of recent new drug applications (2013-2016)

Presented at ISSX conference, September 2017, Providence, RI, USA
Jingjing Yu and Isabelle Ragueneau-Majlessi

2017 ISSX Poster Presentation – 2013-2016 NDA Review


The aim of the present work was to systematically review pharmacokinetic-based drug-drug interaction (DDI) data available in the most recent (2013-2016) New Drug Applications (NDAs) and highlight significant findings. The University of Washington Metabolism and Transport Drug Interaction Database was used to extract the results of metabolism, transport, and clinical DDI studies. All the DDI studies (new molecular entity (NME) as victim or perpetrator) with AUC changes ≥ 2-fold or < 2-fold but triggering dose recommendations were included in the analysis.

Intestinal Drug Interactions Mediated by OATPs: A Systematic Review of Preclinical and Clinical Findings

J Pharm Sci. 2017 Sep; 106(9); 2312-2325
Published online 2017 Apr 13


In recent years, an increasing number of clinical drug-drug interactions (DDIs) have been attributed to inhibition of intestinal organic anion-transporting polypeptides (OATPs); however, only a few of these DDI results were reflected in drug labels. This review aims to provide a thorough analysis of intestinal OATP-mediated pharmacokinetic-based DDIs, using both in vitro and clinical investigations, highlighting the main mechanistic findings and discussing their clinical relevance. On the basis of pharmacogenetic and clinical DDI results, a total of 12 drugs were identified as possible clinical substrates of OATP2B1 and OATP1A2. Among them, 3 drugs, namely atenolol, celiprolol, and fexofenadine, have emerged as the most sensitive substrates to evaluate clinical OATP-mediated intestinal DDIs when interactions with P-glycoprotein by the test compound can be ruled out. With regard to perpetrators, 8 dietary or natural products and 1 investigational drug, ronacaleret (now terminated), showed clinical intestinal inhibition attributable to OATPs, producing ≥20% decreases in area under the plasma concentration-time curve of the co-administered drug. Common juices, such as apple juice, grapefruit juice, and orange juice, are considered potent inhibitors of intestinal OATP2B1 and OATP1A2 (decreasing exposure of the co-administered substrate by ∼85%) and may be adequate prototype inhibitors to investigate intestinal DDIs mediated by OATPs.

What Can Be Learned From Recent New Drug Applications? A Systematic Review of Drug Interaction Data for Drugs Approved by the US FDA in 2015

Drug Metab Dispos. 2017 Jan; 45(1); 86-108.
Published online 2016 Nov 7


As a follow up to previous reviews, the aim of the present analysis was to systematically examine all drug metabolism, transport, pharmacokinetics (PK), and drug-drug interaction (DDI) data available in the 33 new drug applications (NDAs) approved by the Food and Drug Administration (FDA) in 2015, using the University of Washington Drug Interaction Database, and to highlight the significant findings. In vitro, a majority of the new molecular entities (NMEs) were found to be substrates or inhibitors/inducers of at least one drug metabolizing enzyme or transporter. In vivo, 95 clinical DDI studies displayed positive PK interactions, with an area under the curve (AUC) ratio ≥ 1.25 for inhibition or ≤ 0.8 for induction. When NMEs were considered as victim drugs, 21 NMEs had at least one positive clinical DDI, with three NMEs shown to be sensitive substrates of CYP3A (AUC ratio ≥ 5 when coadministered with strong inhibitors): cobimetinib, isavuconazole (the active metabolite of prodrug isavuconazonium sulfate), and ivabradine. As perpetrators, nine NMEs showed positive inhibition and three NMEs showed positive induction, with some of these interactions involving both enzymes and transporters. The most significant changes for inhibition and induction were observed with rolapitant, a moderate inhibitor of CYP2D6 and lumacaftor, a strong inducer of CYP3A. Physiologically based pharmacokinetics simulations and pharmacogenetics studies were used for six and eight NMEs, respectively, to inform dosing recommendations. The effects of hepatic or renal impairment on the drugs’ PK were also evaluated to support drug administration in these specific populations.

Investigating ABCB1-Mediated Drug-Drug Interactions: Considerations for In Vitro and In Vivo Assay Design



ABCB1 is a key ABC efflux transporter modulating the pharmacokinetics of a large percentage of drugs. ABCB1 is also a site of transporter mediated drug-drug interactions (tDDI). It is the transporter most frequently tested for tDDIs both in vitro and in the clinic.


Understanding the limitations of various in vitro and in vivo models, therefore, is crucial. In this review we cover regulatory aspects of ABCB1 mediated drug transport as well as inhibition and the available models and methods. We also discuss protein structure and mechanistic aspects of transport as ABCB1 displays complex kinetics that involves multiple binding sites, potentiation of transport and probe-dependent IC50 values.


Permeability of drugs both passive and mediated by transporters is also a covariate that modulates apparent kinetic values. Levels of expression as well as lipid composition of the expression system used in in vitro studies have also been acknowledged as determinates of transporter activity. ABCB1-mediated clinical tDDIs are often complex as multiple transporters as well as metabolic enzymes may play a role. This complexity often masks the role of ABCB1 in tDDIs.


It is expected that utilization of in vitro data will further increase with the refinement of simulations. It is also anticipated that transporter humanized preclinical models have a significant impact and utility.

Drug Disposition and Drug-Drug Interaction Data in 2013 FDA New Drug Applications: A Systematic Review

Drug Metab Dispos. 2014 Dec; 42(12); 1991-2001.
Published online 2014 Sep 30


The aim of the present work was to perform a systematic review of drug metabolism, transport, pharmacokinetics, and DDI data available in the NDAs approved by the FDA in 2013, using the University of Washington Drug Interaction Database, and to highlight significant findings. Among 27 NMEs approved, 22 (81%) were well characterized with regard to drug metabolism, transport, or organ impairment, in accordance with the FDA drug interaction guidance (2012) and were fully analyzed in this review. In vitro, a majority of the NMEs were found to be substrates or inhibitors/inducers of at least one drug metabolizing enzyme or transporter. However, in vivo, only half (n = 11) showed clinically relevant drug interactions, with most related to the NMEs as victim drugs and CYP3A being the most affected enzyme. As perpetrators, the overall effects for NMEs were much less pronounced, compared with when they served as victims. In addition, the pharmacokinetic evaluation in patients with hepatic or renal impairment provided useful information for further understanding of the drugs’ disposition.

A Useful Tool for Drug Interaction Evaluation: The University of Washington Metabolism and Transport Drug Interaction Database


The Metabolism and Transport Drug Interaction Database ( is a web-based research and analysis tool developed in the Department of Pharmaceutics at the University of Washington. The database has the largest manually curated collection of data related to drug interactions in humans. The tool integrates information from the literature, public repositories, reference textbooks, guideline documents, product prescribing labels and clinical review sections of new drug approval (NDA) packages. The database’s easy-to-use web portal offers tools for visualisation, reporting and filtering of information. The database helps scientists to mine kinetics information for drug-metabolising enzymes and transporters, to assess the extent of in vivo drug interaction studies, as well as case reports for drugs, therapeutic proteins, food products and herbal derivatives. This review provides a brief description of the database organisation, its search functionalities and examples of use.