DMPK & ABC Transporter Assays — Vesicle Kits for FDA/EMA DDI Studies
Drug metabolism and pharmacokinetics (DMPK) studies are mandatory for all new molecular entities (NMEs) before IND submission to the FDA or CTA submission to the EMA. ABC (ATP-binding cassette) transporter inhibition testing is a critical component of this programme — transporters at the liver, kidney, intestine, and blood-brain barrier determine whether a new drug reaches its target, accumulates to toxic levels, or causes drug-drug interactions (DDI) with co-administered medications.
SeamlessBio supplies the Cell4Pharma range of ABC transporter membrane vesicle kits — HEK293-derived inside-out vesicles overexpressing each major human ABC transporter, with 100 reactions per kit, full activity validation per lot, and FDA/EMA DDI Guidance-compliant documentation.
Complete Cell4Pharma Vesicle Kit Portfolio
| Transporter | Gene | Location | Clinical Relevance | Kit |
|---|---|---|---|---|
| BSEP | ABCB11 | Hepatocyte canalicular membrane | Drug-induced liver injury (DILI) — BSEP inhibition causes cholestatic hepatotoxicity. FDA mandatory for all NMEs. | BSEP Vesicle Kit → |
| BCRP | ABCG2 | Intestinal epithelium, liver, BBB, placenta | Oral bioavailability, CNS penetration, DDI with rosuvastatin, methotrexate, imatinib. FDA mandatory. | BCRP Vesicle Kit → |
| P-gp (MDR1) | ABCB1 | Intestine, liver, BBB, kidney, placenta | Most clinically significant efflux transporter — oral bioavailability, CNS exclusion, multi-drug resistance. FDA mandatory. | P-gp Vesicle Kit → |
| P-gp / FluoPgp | ABCB1 | As above | Fluorescent substrate-based P-gp assay — higher throughput, no radiolabel required. Compatible with plate reader detection. | P-gp FluoPgp Kit → |
| MRP1 | ABCC1 | Ubiquitous — basolateral liver, lung, kidney | GSH-conjugate and glucuronide efflux. Multidrug resistance in cancer. Basolateral hepatic efflux in DILI risk assessment. | MRP1 Vesicle Kit → |
| MRP2 | ABCC2 | Hepatocyte canalicular, intestine, kidney | Canalicular bile acid efflux — compensatory pathway when BSEP is inhibited. Dual BSEP/MRP2 inhibition = higher DILI risk. | MRP2 Vesicle Kit → |
| MRP3 | ABCC3 | Basolateral hepatocyte, intestine | Basolateral bile acid safety valve — upregulated when canalicular efflux is impaired. DILI dual liability panel. | MRP3 Vesicle Kit → |
| MRP4 | ABCC4 | Hepatocyte, kidney, platelet | Bile acid renal compensation — alternative efflux when hepatic routes are impaired. Platelet drug transport. | MRP4 Vesicle Kit → |
| MRP5 | ABCC5 | Ubiquitous — brain, heart | Nucleotide and cyclic nucleotide efflux. CNS drug resistance. Cardiac drug accumulation risk. | MRP5 Vesicle Kit → |
| MRP8 | ABCC11 | Liver, brain, breast tissue | Steroid and bile acid conjugate transport. Emerging role in oncology drug resistance. | MRP8 Vesicle Kit → |
| Control Vesicles | Non-transfected HEK293 | — | Background correction — essential for all vesicle assays. ATP-dependent uptake subtraction from non-specific binding. | Control Vesicle Kit → |
Recommended DILI Risk Assessment Panels
| Panel | Transporters | Rationale |
|---|---|---|
| Minimal FDA DDI Panel | BSEP + BCRP + P-gp + Control | Covers FDA mandatory transporters for BSEP (DILI), BCRP and P-gp (DDI). Minimum IND-enabling transporter package. |
| DILI Risk Panel | BSEP + MRP2 + MRP3 + MRP4 + Control | Complete hepatic transporter panel — dual/triple liability assessment. Identifies DILI risk from compensatory pathway inhibition beyond BSEP alone. |
| Full DDI Panel | All 11 kits | Comprehensive transporter inhibition profile for NMEs with complex ADME or known hepatic/renal metabolism. Supports complete IND DDI section. |
Kit Specifications
| Parameter | Specification |
|---|---|
| Expression system | HEK293 — inside-out membrane vesicles overexpressing human ABC transporter |
| Reactions per kit | 100 reactions |
| Orientation | Inside-out — ATP-dependent transport into vesicle lumen |
| Substrate | Radiolabelled or MS-detectable — taurocholic acid (BSEP), estradiol glucuronide (MRP2), methotrexate (MRP), vinblastine (P-gp) |
| Lot validation | IC₅₀ with reference inhibitor per lot — cyclosporine A (BSEP/P-gp), Ko143 (BCRP), MK-571 (MRP) |
| Documentation | CoA with activity data, cell line documentation, lot-specific quality data |
| Regulatory compliance | FDA 2020 DDI Guidance, EMA 2012 DDI Guideline, ICH M12 |
| Storage | −80°C | Avoid freeze-thaw cycles |
Frequently Asked Questions
Which transporters are mandatory for FDA IND submission?
The FDA 2020 Drug Interaction Guidance requires evaluation of P-gp, BCRP, OATP1B1, OATP1B3, OCT1, OCT2, OAT1, OAT3, MATE1, and MATE2K for all NMEs. BSEP evaluation is recommended for all NMEs as part of hepatotoxicity risk assessment. The membrane vesicle assay is the accepted method for P-gp, BCRP, BSEP, and MRP family transporters.
Why is the Control Vesicle Kit required?
Control vesicles from non-transfected HEK293 cells are essential for background correction in all vesicle assays. They measure non-specific ATP-dependent uptake and passive substrate accumulation in vesicle preparations without the transporter of interest. ATP-dependent transport = (signal in transporter vesicles) − (signal in control vesicles). Without this subtraction, IC₅₀ values are unreliable.
What is the dual liability concept for DILI risk?
BSEP inhibition alone is a necessary but not always sufficient predictor of clinical DILI. Simultaneous inhibition of BSEP and MRP2 or MRP3 impairs both the primary canalicular bile acid efflux pathway and the compensatory basolateral safety valve — dramatically increasing intracellular bile acid accumulation and hepatotoxicity risk. Testing the complete BSEP/MRP2/MRP3/MRP4 panel provides a more accurate DILI risk profile than BSEP alone.
Related Applications
| Application | Link |
|---|---|
| BSEP & DILI — blog post | BSEP Inhibition & DILI → |
| Cell4Pharma kit collection | Cell4Pharma Vesicle Kits → |
Technical enquiries, DMPK panel recommendations: info@seamlessbio.de | +49 851 37932226