Drug-Drug Interaction
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Comprehensive Testing Services for Your DDI Studies
As your partner, WuXi AppTec offers a comprehensive portfolio of in vitro assays specifically designed to meet global regulatory drug-drug interaction (DDI) guidelines. This includes guidance from U.S. Food and Drug Administration (FDA), European Medical Agency (EMA) and China’s National Medical Products Administration (NMPA). We also offer analysis of mechanisms of inhibition, which provides key information for successful planning and design of clinical DDI studies.
Our DDI Testing Capabilities
Transporter-Mediated Drug Interaction Study
Transporters are a group of carrier proteins that influence drugs’ pharmacokinetics, pharmacodynamics, and toxicological properties. Drug-related transporters in humans mainly contain two types of transporter super-families, i.e. ATP-binding cassette (ABC) transporters and solute carrier (SLC) transporters. Transporters can affect the absorption, distribution, elimination, and other in vivo processes of drugs, affecting the efficacy and safety of drugs and playing an essential role in DDIs [1]. Usually, in vitro testing is the first step in assessing transporter-mediated DDIs, which were recommended by FDA, NMPA and EMA (Table 1).
Table 1: Regulatory Guidance for Transporter Investigation
| Transporters | FDA[2] | NMPA [3] | EMA[4] | |
| ABC | P-gp | ✓ | ✓ | ✓ |
| BCRP | ✓ | ✓ | ✓ | |
| BSEP | – | – | Preferably be investigated | |
| SLC | OATP1B1 | ✓ | ✓ | ✓ |
| OATP1B3 | ✓ | ✓ | ✓ | |
| OAT1 | ✓ | ✓ | ✓ | |
| OAT3 | ✓ | ✓ | ✓ | |
| OCT1 | – | – | Be considered | |
| OCT2 | ✓ | ✓ | ✓ | |
| MATE1 | ✓ | ✓ | Be considered | |
| MATE2-K | ✓ | ✓ | Be considered | |
How Our Platform Works
WuXi AppTec’s in vitro transporter platform provides various in vitro models for assessing transporter-mediated DDIs. We can evaluate substrates or inhibitors of specific transporters using the following types of cell-based models:
- Human embryonic kidney cells (HEK 293 cells) stably transfected with transporter genes
- MDR1‑MDCK I and MDR1-MDCK II cells specifically expressing P-gp
- Caco-2 cells expressing efflux transporters [2]
In addition, we provide the vesicles models for efflux transporters BSEP and MRP2 and establish a model for the comprehensive assessment of hepatic uptake using primary hepatocytes. Details of the models are in Table 2.
Table 2: In vitro Transporter Models
| Model | Features | Assay Type | |
|
Cell-based Models |
HEK-293 Cells- transfected with SLC Transporters |
HEK-293 cells transfected with the human SLC transporter gene, which specifically express the SLC transporter To assess transporter-mediated DDIs for OATP1B1, OATP1B3, OATP2B1, OAT1, OAT3, OCT1, OCT2, MATE1, MATE2‑K, PEPT1, PEPT2 and NTCP |
SLC transporter substrate assessment assays SLC transporter inhibition assays |
| MDR1-MDCK II Cells |
MDCK II cells transfected with the human MDR1 gene encoding for the efflux transporter, P-gp To assess P-gp-mediated DDIs |
P-gp substrate assessment assay P-gp inhibition assay |
|
| MDR1-MDCK I Cells |
MDCK I cells transfected with the human MDR1 gene encoding for the efflux transporter, P-gp To assess P-gp-mediated DDIs To predict P-gp substrates at BBB in vivo |
P-gp substrate assessment assay P-gp inhibition assay |
|
| Caco-2 Cells |
A human colon cancer cell that expresses multiple transporters, such as efflux transporters P-gp and BCRP To assess P-gp and BCRP mediated DDIs |
P-gp and BCRP substrate assessment assays P-gp and BCRP inhibition assays |
|
| Primary Hepatocytes |
Suspension primary hepatocytes To assess hepatic uptake Species: human, monkey, dog, rat, and mouse |
Hepatic uptake assay | |
| Non-cell-based Models | Vesicles |
Vesicles expressing efflux transporters BSEP and MRP2 To assess BSEP and MRP2 mediated DDIs |
BSEP and MRP2 substrate assessment assays BSEP and MRP2 inhibition assays |
Metabolism-Mediated Drug Interaction Study
Metabolic enzymes mediated DDIs include determining the main routes of drug elimination and assessing the contribution of relevant metabolic enzymes to drug disposition (enzyme metabolic reaction phenotyping experiments). It also includes investigating the drug’s effect on metabolic enzymes (enzyme inhibition or induction experiments). DDI involves the influence of one drug, the “perpetrator,” with the metabolic or pharmacokinetic behavior of a co-administered drug, the “victim.” If the perpetrator inhibits a CYP, this can decrease the metabolic clearance of a victim that CYP primarily metabolizes. Likewise, if the perpetrator activates the CYP, it will expedite the victim’s clearance. Similarly, if the victim is a prodrug converted to the parent or active drug by a CYP, then inhibitive or activating perpetrators will decrease or increase the serum concentrations of the active drug, respectively. Inhibition of cytochrome P450 enzymes causes toxic side effects that may be improved by changes in treatment regimens. Still, drug interactions may lead to severe adverse effects, which lead to some drugs being terminated at an early stage of development and/or even withdrawn from the market.
How Our Platform Works
WuXi AppTec’s DDI platform provides tier-based DDI assays which meet the requirements of different stages in drug discovery and development, namely: lead finding (LF), lead optimization (LO), preclinical candidate (PCC), and investigational new drug (IND). Details of the in vitro enzyme models are in Table 3.
Table 3: In vitro Enzymes Models
| Model | Study Purpose | Assay Type |
| Cytochrome P450 enzyme reversible inhibition test | Evaluate the inhibitory effect of compounds on the activity of human liver microsomal cytochrome P450 isozymes (e.g., CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A) using probe substrates for each isozyme |
CYP inhibition – IC50 for 5 CYPs (5 in 1 cocktail substrate) |
|
CYP inhibition – IC50 for 7 CYPs (discrete substrate) |
||
| Evaluate the inhibition constants (Ki) of compounds on human liver microsomal cytochrome P450 isozymes (e.g., CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A) using probe substrates for each isozyme | Determined Ki value assay | |
| Reversible inhibition test of recombinant human uridine diphosphate glucuronosyltransferases | Evaluate the inhibitory effect of compounds on recombinant human uridine diphosphate glucuronosyltransferase (UGT enzymes) activities such as UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, and UGT2B15 | UGT Inhibition Assay using rhUGTs |
| Cytochrome P450 enzyme Time-dependent inhibition test | Evaluate the time-dependent inhibitory effects of compounds on human liver microsomal cytochrome P450 isozymes (e.g., CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A) | CYP time dependent inhibition (IC50 shift) |
| Evaluate the kinetic parameters (kinact/KI) for the irreversible inhibition of cytochrome P450 isozymes (e.g., CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A) of compounds | Determination of kinact/KI | |
| Cytochrome P450 Enzyme Metabolic Reaction Phenotyping Experiment | Identify cytochrome P450 isozymes involved in the in vitro metabolism of compounds in human liver microsomes and determine the relative contributions of various isozymes in metabolism (e.g., CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A) |
CYP Phenotyping assay using recombinant CYPs/human liver microsomes |
| Metabolic Reaction Phenotype of Recombinant Human Uridine Diphosphate Glucuronosyltransferases | Identify recombinant human uridine diphosphate glucuronosyltransferases involved in compound metabolism (e.g., UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, and UGT2B15) | UGT Phenotyping assay using recombinant UGTs |
| Cytochrome P450 enzyme induction test | Evaluation of the induction potential of a compound on enzyme activities and gene expression levels of cytochrome P450 isozymes (e.g., CYP1A2, CYP2B6, CYP3A4, and CYP2C8, CYP2C9, and CYP2C19) by in vitro hepatocyte induction experiments | CYP induction assays |
REFERENCES
- Giacomini, K.M. et al. Membrane transporters in drug development. Nature reviews drug discovery 9, 215-236 (2010)
- Food and Drug Administration Center for Drug Evaluation and Research (2020). Clinical Drug Interaction Studies —Cytochrome P450 Enzyme- and Transporter-Mediated Drug Interactions Guidance for Industry (FDA Maryland)
- 药物相互作用研究技术指导原则（试行）(2021, 国家药监局药审中心)
- Guideline on the Investigation of Drug Interactions (2013, EMA)