Cardiac Safety Screening
High-quality Cardiac Safety Screening assays, including components of the Comprehensive in Vitro Proarrhythmia Assay (CiPA) initiative
Reliably evaluate the proarrhythmic and cardiotoxic liabilities of your compounds by assessing their effects against a comprehensive panel of cardiac ion channels
Introduction to Metrion’s Cardiac Safety Screening services
Metrion offers a range of high-quality Cardiac Safety Screening assays, including components of the Comprehensive in Vitro Proarrhythmia Assay (CiPA) initiative. Our services include assays that evaluate the proarrhythmic and cardiotoxic liabilities of compounds by assessing their effects on:
- A comprehensive panel of human cardiac ion channels, including all six CiPA ion channels, using gigaohm seal quality automated electrophysiology devices.
- Action potentials recorded from human iPSC-derived cardiomyocytes using multi
- The contractility and viability of human iPSC-derived cardiomyocytes using an impedance platform.
Our assay technologies include Qube, QPatch and Patchliner automated electrophysiology, conventional manual patch clamp electrophysiology, and plate-based impedance and microelectrode array techniques.
Introduction to CiPA
The regulatory landscape
The International Council on Harmonization (ICH) S7B and E14 regulatory guidelines were introduced in 2005 to evaluate the proarrhythmic liability of new drugs. They were implemented in response to the discovery that inhibition of a cardiac potassium channel (Kv11.1 or IKr, better known as hERG) is associated with prolongation of the QT interval and a potentially deadly arrhythmia, Torsades de Pointes.
The guidelines utilise hERG inhibition and QT interval prolongation as surrogate markers of proarrhythmic liability, which are highly sensitive and have proven effective at preventing proarrhythmic drugs from reaching the market. However, these markers have low specificity, with only a modest correlation between hERG inhibition, QT prolongation and proarrhythmic liability. Therefore, to address these limitations, the Comprehensive in Vitro Proarrhythmia Assay (CiPA) initiative was launched by the FDA in July 2013. The CiPA initiative aims to improve the accuracy and reduce the cost of predicting cardiac liability using three ‘pillars’:
The three pillars of CiPA
- Compounds will be profiled against a panel of human ventricular ion channels.
- This in vitro data will be incorporated into an in silico model of a human action potential to provide a proarrhythmic risk classification.
- Compounds will be tested using human induced pluripotent stem cell- derived cardiomyocytes to confirm the risk classification derived from the in silico model.
Metrion has developed a comprehensive panel of CiPA compliant assays and additional assays that provide an excellent in vitro evaluation of cardiac risk.
Comprehensive ion channel panel
Metrion is an active participant in the CiPA ion channel HTS sub-team and a member of the Health and Environmental Sciences Institute (HESI) cardiac committee. We work closely with HESI to help reduce data variability between screening sites and to provide validation data to support the efforts to generate predictive in silico models. Through these activities, Metrion has validated assays for a wide range of different human ventricular ion channels, which includes the full CiPA panel (hERG, peak and late Nav1.5, Cav1.2, KCNQ1/KCNE1, Kir2.1 and Kv4.3).
Metrion also offers screening services against HCN4 and Kv1.5, which play important roles in controlling humanheart rate and atrial repolarisation, respectively. Metrion have also recently validated additional assays for key members of the core panel of human cardiac ion channels, namely a dynamic hERG and an LQT3 late Nav1.5 assay, both of which are detailed on our Application Notes page. These new cardiac assay formats have been shown to improve the prediction of human clinical arrythmia risk.
Automated and manual patch clamp screening available
Metrion provides potency assessment against each of the CiPA cardiac channels using single-point or four-point concentration-response assays developed on the QPatch48, which is a gigaohm seal quality automated patch clamp device. In addition, compounds can also be screened against these ion channel targets using manual patch clamp methodology. The high quality IC50 values derived from these high fidelity platforms are suitable for use in in silico action potential models, which is the second ‘pillar’ of the CiPA initiative.
Dynamic hERG assay
It is also possible to create new screening assays from existing cell lines.
As part of our efforts to create an expanded panel of CiPA-compliant cardiac safety assays, we developed and validated an optimised version of the very challenging ‘Milnes’ dynamic hERG voltage protocol suitable for automated patch clamp.
This protocol is designed to measure the potential for test compounds to become trapped inside the hERG channel pore, and Metrion’s dynamic hERG assay is the first to be validated on an automated patch clamp platform.
Proarrhythmia assays – hiPSC derived cardiomyocytes
Metrion has developed a range of high-quality assays that evaluate the effect of compounds on the electrophysiological properties of human iPSC-derived cardiomyocytes. This includes a multi
The below image shows the effect of three concentrations of dofetilide on a range of iPSC cardiomyocyte electrophysiological parameters. Data could not be collected for the two highest concentrations, as early after depolarisations (EADs) were observed after five minutes of application, which later degenerated into fibrillation at the top screening concentration.
Custom MEA assay service
Metrion can provide custom MEA assays to evaluate the proarrhythmic liability of compounds. For example, due to the non-invasive nature of the MEA system, the application duration of compounds can be extended to hours or days. This allows for the detection of compounds that may affect ion channel function or expression over hours, rather than minutes.
iPSC-derived cardiomyocyte screening
Metrion also provides services to evaluate the effect of compounds on action potentials recorded from iPSC-derived cardiomyocytes using conventional manual patch clamp methodology. Spontaneous or evoked action potentials can be recorded and used to determine the effect of compounds on a range of action potential parameters. The recordings are stable for >30 minutes, which allows the cumulative application of multiple concentrations of each compound.
The manual patch clamp assay generates high fidelity recordings that allow the detection of even subtle changes to the action potential waveform. This helps to successfully discern between compounds with low, medium and high proarrhythmic risk profiles. For example, the figures below show mean data generated using 50 nM dofetilide, which reveals a significant prolongation of all measured APD values.
Additionally, dofetilide produced triangulation of the action potential waveform and, in alignment with the MEA assay, elicited EADs that are a putative torsadogenic trigger in vivo. Furthermore, dofetilide produced substantial action potential instability, which is illustrated in the Poincaré plot in Fig. 3c where there was large variability in the beat-to-beat APD90 value. Collectively, the data indicate that this is a compound with a high proarrhythmic risk liability.
Chronic cardiotoxicity assay – hiPSC derived cardiomyocytes
Base impedance, which is an indicator of cell viability, can be used to non-invasively identify structural and functional cardiotoxicity over a chronic time course. Metrion has developed a chronic cardiotoxicity assay using human iPSC-derived cardiomyocytes, which has been validated with a number of cardiotoxicants. For example, doxorubicin, a member of the anthracycline family that is used to treat breast cancer, is associated with a number of cardiac side effects, which includes acute atrial and ventricular arrhythmias, chronic cardiomyopathy and congestive heart failure. Metrion’s chronic cardiotoxicity assay recapitulates doxorubicin’s cardiotoxic effect by producing a concentration-dependent decrease of base impedance that develops following a 24 hour exposure period.
Metrion’s Cardiac Safety Screening Resource Library
- CiPA hERG Milnes Kinetic Assay on Qpatch
- Nav1.5(late) Cardiac Safety Assay on Qpatch
- Nav1.5-ΔKPQ late INa current properties and pharmacology on the SyncroPatch 384i
- A systematic strategy for estimating hERG block potency and its implications in a new cardiac safety paradigm.
- Cross-site and cross-platform variability of automated patch clamp assessments of drug effects on human cardiac currents in recombinant cells.
- The Nav1.5 Late Current in WT and Nav1.5 ΔKPQ Mutant Channels: An Automated Patch Clamp LQT3 Electrophysiological Assay Comparison. Safety Pharmacology Society Virtual Meeting 2020.
- New CiPA Cardiac Ion Channel Cell Lines and Assays for In Vitro Proarrhythmia Risk Assessment. Japanese Safety Pharmacology Society Meeting, Tokyo, 2020
- Using new In Vitro Cardiac Ion Channel Assays and In Silico Models to Predict Proarrhythmia Risk with Automated Patch Clamp. Biophysical Society Annual Meeting, San Diego, 2020
- Development of an Impedance Based Screening Assay for Cardiac Safety and Cardiotoxicity Detection in Stem Cell derived Cardiomyocytes. Safety Pharmacology Society Annual Meeting, Barcelona, 2019
- Predicting Cardiac Proarrhythmic Risk Exclusively Using Automated Patch Clamp Data. Safety Pharmacology Society Annual Meeting, Barcelona, 2019
- New CiPA cardiac ion channel cell lines and assays for in vitro proarrhythmia risk assessment. Safety Pharmacology Society meeting, Washington DC, USA 2018.
- Assessment of human induced pluripotent stem cell-derived cardiomyocytes for evaluating drug-induced arrhythmias with multi-electrode array. Safety Pharmacology Society meeting, Washington DC, USA 2018.
- Refining in vitro QPatch cardiac ion channel QPatch and MEA iPSC cardiomyocyte assays for CiPA. SOT San Antonio 2018 poster Late Breaking 12: Safety Assessment: Pharmaceutical and Non-Pharmaceutical.
- CiPA update: Refining in vitro cardiac ion channel assays, in silico models and iPSC cardiomyocyte reagents for improved proarrhythmia risk prediction. SPS Vancouver September 2016 poster 0100.
- Human ventricular stem cell cardiomyocytes: validating in vitro assays and screening platforms for proarrhythmia risk prediction. SPS Vancouver September 2016 poster 0242.
- Human stem cell-derived cardiomyocytes: in vitro assays and screening platforms for exploring ventricular and atrial phenotypes. SPS Vancouver September 2016 poster 0247.
- Electrophysiological profiling of Axiogenesis CorV.4U iPSC-derived cardiomyocytes. Axiogenesis Workshop Cologne September 2016.
- Developing a package of in vitro human cardiac ion channel assays using automated patch clamp to predict clinical arrhythmia risk. SPS Prague September 2015.
- Presentation by Marc Rogers (Metrion CSO) at the June 2016 Sophion Ion Channel Modulation Symposium, Clare College, Cambridge (UK). CiPA update: in vitro cardiac ion channels screens, in silico models and stem cells iPS cardiomyocyte assays for pro-arrhythmia risk prediction.
- Presentation by Marc Rogers (Metrion CSO) at the September 2015 Safety Pharmacological Society, Prague. Using high quality HTS automated patch clamp data from human cardiac ion channels and in silico action potential modelling to cost-effectively predict QP prolongation and arrhythmia risk for CiPA.
Cardiac Safety Screening Technologies
- QPatch automated electrophysiology platform
- Patchliner automated electrophysiology
- Conventional manual patch clamp electrophysiology
- Plate-based impedance and microelectrode array techniques
- FlexStation plate-based imaging
Let’s work together
What are your specific ion channel screening requirements?
If you have any questions, or would like to discuss your project, we will put you directly in touch with a member of our scientific team. Contact us today to discover more.