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Escobar F, Friis S, Adly N, Brinkwirth N, Gomis-Tena J, Saiz J, Klaerke DA, Stoelzle-Feix S, Romero L. Experimentally validated modeling of dynamic drug-hERG channel interactions reproducing the binding mechanisms and its importance in action potential duration. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 254:108293. [PMID: 38936153 DOI: 10.1016/j.cmpb.2024.108293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 06/09/2024] [Accepted: 06/16/2024] [Indexed: 06/29/2024]
Abstract
BACKGROUND AND OBJECTIVE Assessment of drug cardiotoxicity is critical in the development of new compounds and modeling of drug-binding dynamics to hERG can improve early cardiotoxicity assessment. We previously developed a methodology to generate Markovian models reproducing preferential state-dependent binding properties, trapping dynamics and the onset of IKr block using simple voltage clamp protocols. Here, we test this methodology with real IKr blockers and investigate the impact of drug dynamics on action potential prolongation. METHODS Experiments were performed on HEK cells stably transfected with hERG and using the Nanion SyncroPatch 384i. Three protocols, P-80, P0 and P 40, were applied to obtain the experimental data from the drugs and the Markovian models were generated using our pipeline. The corresponding static models were also generated and a modified version of the O´Hara-Rudy action potential model was used to simulate the action potential duration. RESULTS The experimental Hill plots and the onset of IKr block of ten compounds were obtained using our voltage clamp protocols and the models generated successfully mimicked these experimental data, unlike the CiPA dynamic models. Marked differences in APD prolongation were observed when drug effects were simulated using the dynamic models and the static models. CONCLUSIONS These new dynamic models of ten well-known IKr blockers constitute a validation of our methodology to model dynamic drug-hERG channel interactions and highlight the importance of state-dependent binding, trapping dynamics and the time-course of IKr block to assess drug effects even at the steady-state.
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Affiliation(s)
- Fernando Escobar
- Centro de Innovación e Investigación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain
| | | | | | | | - Julio Gomis-Tena
- Centro de Innovación e Investigación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain
| | - Javier Saiz
- Centro de Innovación e Investigación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain
| | - Dan A Klaerke
- Department of Pathobiology, University of Copenhagen, Copenhagen, Denmark
| | | | - Lucia Romero
- Centro de Innovación e Investigación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain.
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2
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Qauli AI, Danadibrata RZ, Marcellinus A, Lim KM. Development of in-silico drug cardiac toxicity evaluation system with consideration of inter-individual variability. Transl Clin Pharmacol 2024; 32:83-97. [PMID: 38974343 PMCID: PMC11224897 DOI: 10.12793/tcp.2024.32.e7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 04/30/2024] [Accepted: 05/26/2024] [Indexed: 07/09/2024] Open
Abstract
Safety pharmacology examines the potential for new drugs to have unusual, rare side effects such as torsade de pointes (TdP). Recently, as a part of the Comprehensive in vitro Proarrhythmia Assay (CiPA) project, techniques for predicting the development of drug-induced TdP through computer simulations have been proposed and verified. However, CiPA assessment generally does not consider the effect of cardiac cell inter-individual variability, especially related to metabolic status. The study aimed to explore whether rare proarrhythmic effects may be linked to the inter-individual variability of cardiac cells and whether incorporating this variability into computational models could alter the prediction of drugs' TdP risks. This study evaluated the contribution of two biological characteristics to the proarrhythmic effects. The first was spermine concentration, which varies with metabolic status; the second was L-type calcium permeability that could occur due to mutations. Twenty-eight drugs were examined throughout this study, and qNet was analyzed as an essential feature. Even though there were some discrepancies of TdP risk predictions from the baseline model, we found that considering the inter-individual variability might change the TdP risk of drugs. Several drugs in the high-risk drugs group were predicted to affect as intermediate and low-risk drugs in some individuals and vice versa. Also, most intermediate-risk drugs were expected to act as low-risk drugs. When compared, the effects of inter-individual variability of L-type calcium were more significant than spermine in altering the TdP risk of compounds. These results emphasize the importance of considering inter-individual variability to assess drugs.
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Affiliation(s)
- Ali Ikhsanul Qauli
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
- Department of Engineering, Faculty of Advanced Technology and Multidiscipline, Universitas Airlangga, Surabaya 60115, Indonesia
| | | | - Aroli Marcellinus
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
| | - Ki Moo Lim
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
- Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
- Meta Heart Inc., Gumi 39177, Korea
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3
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Fuadah YN, Qauli AI, Marcellinus A, Pramudito MA, Lim KM. Machine learning approach to evaluate TdP risk of drugs using cardiac electrophysiological model including inter-individual variability. Front Physiol 2023; 14:1266084. [PMID: 37860622 PMCID: PMC10584148 DOI: 10.3389/fphys.2023.1266084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/20/2023] [Indexed: 10/21/2023] Open
Abstract
Introduction: Predicting ventricular arrhythmia Torsade de Pointes (TdP) caused by drug-induced cardiotoxicity is essential in drug development. Several studies used single biomarkers such as qNet and Repolarization Abnormality (RA) in a single cardiac cell model to evaluate TdP risk. However, a single biomarker may not encompass the full range of factors contributing to TdP risk, leading to divergent TdP risk prediction outcomes, mainly when evaluated using unseen data. We addressed this issue by utilizing multi-in silico features from a population of human ventricular cell models that could capture a representation of the underlying mechanisms contributing to TdP risk to provide a more reliable assessment of drug-induced cardiotoxicity. Method: We generated a virtual population of human ventricular cell models using a modified O'Hara-Rudy model, allowing inter-individual variation. IC 50 and Hill coefficients from 67 drugs were used as input to simulate drug effects on cardiac cells. Fourteen features (dVm dt repol , dVm dt max , Vm peak , Vm resting , APD tri , APD 90 , APD 50 , Ca peak , Ca diastole , Ca tri , CaD 90 , CaD 50 , qNet, qInward) could be generated from the simulation and used as input to several machine learning models, including k-nearest neighbor (KNN), Random Forest (RF), XGBoost, and Artificial Neural Networks (ANN). Optimization of the machine learning model was performed using a grid search to select the best parameter of the proposed model. We applied five-fold cross-validation while training the model with 42 drugs and evaluated the model's performance with test data from 25 drugs. Result: The proposed ANN model showed the highest performance in predicting the TdP risk of drugs by providing an accuracy of 0.923 (0.908-0.937), sensitivity of 0.926 (0.909-0.942), specificity of 0.921 (0.906-0.935), and AUC score of 0.964 (0.954-0.975). Discussion and conclusion: According to the performance results, combining the electrophysiological model including inter-individual variation and optimization of machine learning showed good generalization ability when evaluated using the unseen dataset and produced a reliable drug-induced TdP risk prediction system.
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Affiliation(s)
- Yunendah Nur Fuadah
- Computational Medicine Lab, Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
- School of Electrical Engineering, Telkom University, Bandung, Indonesia
| | - Ali Ikhsanul Qauli
- Computational Medicine Lab, Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
- Department of Engineering, Faculty of Advanced Technology and Multidiscipline, Universitas Airlangga, Surabaya, Jawa Timur, Indonesia
| | - Aroli Marcellinus
- Computational Medicine Lab, Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
| | - Muhammad Adnan Pramudito
- Computational Medicine Lab, Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
| | - Ki Moo Lim
- Computational Medicine Lab, Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
- Computational Medicine Lab, Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
- Meta Heart Co., Ltd., Gumi, Republic of Korea
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Amarh E, Tisdale JE, Overholser BR. Prolonged Exposure to Remdesivir Inhibits the Human Ether-A-Go-Go-Related Gene Potassium Current. J Cardiovasc Pharmacol 2023; 82:212-220. [PMID: 37410999 PMCID: PMC10527785 DOI: 10.1097/fjc.0000000000001449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/22/2023] [Indexed: 07/08/2023]
Abstract
ABSTRACT Remdesivir, approved for the treatment of COVID-19, has been associated with heart-rate corrected QT interval (QTc) prolongation and torsade de pointes in case reports. However, data are conflicting regarding the ability of remdesivir to inhibit the human ether-a-go-go-related gene (hERG) -related current. The objective of this study was to investigate the effects remdesivir and its primary metabolite, GS-441524, on hERG-related currents. Human embryonic kidney 293 cells stably expressing hERG were treated with various concentrations of remdesivir and GS-441524. The effects of acute and prolonged exposure on hERG-related current were assessed using whole-cell configuration of voltage-clamp protocols. Acute exposure to remdesivir and GS-441524 had no effect on hERG currents and the half-activation voltage (V 1/2 ). Prolonged treatment with 100 nM and 1 µM remdesivir significantly reduced peak tail currents and hERG current density. The propensity for remdesivir to prolong QTc intervals and induce torsade de pointes in predisposed patients warrants further investigation.
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Affiliation(s)
- Enoch Amarh
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, Indiana
| | - James E. Tisdale
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, Indiana
- Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Brian R. Overholser
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, Indiana
- Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, Indiana
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Helliwell MV, Zhang Y, El Harchi A, Dempsey CE, Hancox JC. Inhibition of the hERG Potassium Channel by a Methanesulphonate-Free E-4031 Analogue. Pharmaceuticals (Basel) 2023; 16:1204. [PMID: 37765012 PMCID: PMC10536391 DOI: 10.3390/ph16091204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 09/29/2023] Open
Abstract
hERG (human Ether-à-go-go Related Gene)-encoded potassium channels underlie the cardiac rapid delayed rectifier (IKr) potassium current, which is a major target for antiarrhythmic agents and diverse non-cardiac drugs linked to the drug-induced form of long QT syndrome. E-4031 is a high potency hERG channel inhibitor from the methanesulphonanilide drug family. This study utilized a methanesulphonate-lacking E-4031 analogue, "E-4031-17", to evaluate the role of the methanesulphonamide group in E-4031 inhibition of hERG. Whole-cell patch-clamp measurements of the hERG current (IhERG) were made at physiological temperature from HEK 293 cells expressing wild-type (WT) and mutant hERG constructs. For E-4031, WT IhERG was inhibited by a half-maximal inhibitory concentration (IC50) of 15.8 nM, whilst the comparable value for E-4031-17 was 40.3 nM. Both compounds exhibited voltage- and time-dependent inhibition, but they differed in their response to successive applications of a long (10 s) depolarisation protocol, consistent with greater dissociation of E-4031-17 than the parent compound between applied commands. Voltage-dependent inactivation was left-ward voltage shifted for E-4031 but not for E-4031-17; however, inhibition by both compounds was strongly reduced by attenuated-inactivation mutations. Mutations of S6 and S5 aromatic residues (F656V, Y652A, F557L) greatly attenuated actions of both drugs. The S624A mutation also reduced IhERG inhibition by both molecules. Overall, these results demonstrate that the lack of a methanesulphonate in E-4031-17 is not an impediment to high potency inhibition of IhERG.
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Affiliation(s)
- Matthew V. Helliwell
- School of Biochemistry, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK; (M.V.H.); (C.E.D.)
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK; (Y.Z.); (A.E.H.)
| | - Yihong Zhang
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK; (Y.Z.); (A.E.H.)
| | - Aziza El Harchi
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK; (Y.Z.); (A.E.H.)
| | - Christopher E. Dempsey
- School of Biochemistry, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK; (M.V.H.); (C.E.D.)
| | - Jules C. Hancox
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK; (Y.Z.); (A.E.H.)
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6
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In silico assessment on TdP risks of drug combinations under CiPA paradigm. Sci Rep 2023; 13:2924. [PMID: 36807374 PMCID: PMC9940090 DOI: 10.1038/s41598-023-29208-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023] Open
Abstract
Researchers have recently proposed the Comprehensive In-vitro Proarrhythmia Assay (CiPA) to analyze medicines' TdP risks. Using the TdP metric known as qNet, numerous single-drug effects have been studied to classify the medications as low, intermediate, and high-risk. Furthermore, multiple medication therapies are recognized as a potential method for curing patients, mainly when limited drugs are available. This work expands the TdP risk assessment of drugs by introducing a CiPA-based in silico analysis of the TdP risk of combined drugs. The cardiac cell model was simulated using the population of models approach incorporating drug-drug interactions (DDIs) models on several ion channels for various drug pairs. Action potential duration (APD90), qNet, and calcium duration (CaD90) were computed and analyzed as biomarker features. The drug combination maps were also used to illustrate combined medicines' TdP risk. We found that the combined drugs alter cell responses in terms of biomarkers such as APD90, qNet, and CaD90 in a highly nonlinear manner. The results also revealed that combinations of high-risk with low-risk and intermediate-risk with low-risk drugs could result in compounds with varying TdP risks depending on the drug concentrations.
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7
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Escobar F, Gomis-Tena J, Saiz J, Romero L. Automatic modeling of dynamic drug-hERG channel interactions using three voltage protocols and machine learning techniques: A simulation study. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 226:107148. [PMID: 36170760 DOI: 10.1016/j.cmpb.2022.107148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 09/12/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Assessment of drug cardiac safety is critical in the development of new compounds and is commonly addressed by evaluating the half-maximal blocking concentration of the potassium human ether-à-go-go related gene (hERG) channels. However, recent works have evidenced that the modelling of drug-binding dynamics to hERG can help to improve early cardiac safety assessment. Our goal is to develop a methodology to automatically generate Markovian models of the drug-hERG channel interactions. METHODS The training and the test sets consisted of 20800 and 5200 virtual drugs, respectively, distributed into 104 groups with different affinities and kinetics to the conformational states of the channel. In our system, drugs may bind to any state (individually or simultaneously), with different degrees of preference for a conformational state and the change of the conformational state of the drug bound channels may be restricted or allowed. To model such a wide range of possibilities, 12 Markovian chains are considered. Our approach uses the response of the drugs to our three previously developed voltage clamp protocols, which enhance the differences in the probabilities of occupying a certain conformational state of the channel (open, closed and inactivated). The computing tool is comprised of a classifier and a parameter optimizer and uses linear interpolation, support vector machines and a simplex method for function minimization. RESULTS We propose a novel methodology that automatically generates dynamic drug models using Markov model formulations and that elucidates the states where the drug binds and unbinds and the preferential binding state using data obtained from simple voltage clamp protocols that captures the preferential state-dependent binding properties, the relative affinities, trapping and non-trapping dynamics and the onset of IKr block. Overall, the tool correctly predicted the class of 92.04% of the drugs and the model provided by the tool accurately fitted the response of the target compound, the mean accuracy being 97.53%. Moreover, generation of the dynamic model of an IKr blocker from its response to our voltage clamp protocols usually takes less than an hour on a common desktop computer. CONCLUSION Our methodology could be very useful to model and simulate dynamic drug-hERG channel interactions. It would contribute to the improvement of the preclinical assessment of the proarrhythmic risk of drugs that inhibit IKr and the efficacy of antiarrhythmic IKr blockers.
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Affiliation(s)
- Fernando Escobar
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València
| | - Julio Gomis-Tena
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València
| | - Lucía Romero
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València.
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Al-Moubarak E, Sharifi M, Hancox JC. In silico Exploration of Interactions Between Potential COVID-19 Antiviral Treatments and the Pore of the hERG Potassium Channel-A Drug Antitarget. Front Cardiovasc Med 2021; 8:645172. [PMID: 34017865 PMCID: PMC8129016 DOI: 10.3389/fcvm.2021.645172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/30/2021] [Indexed: 12/24/2022] Open
Abstract
Background: In the absence of SARS-CoV-2 specific antiviral treatments, various repurposed pharmaceutical approaches are under investigation for the treatment of COVID-19. Antiviral drugs considered for this condition include atazanavir, remdesivir, lopinavir-ritonavir, and favipiravir. Whilst the combination of lopinavir and ritonavir has been previously linked to prolongation of the QTc interval on the ECG and risk of torsades de pointes arrhythmia, less is known in this regard about atazanavir, remdesivir, and favipiravir. Unwanted abnormalities of drug-induced QTc prolongation by diverse drugs are commonly mediated by a single cardiac anti-target, the hERG potassium channel. This computational modeling study was undertaken in order to explore the ability of these five drugs to interact with known determinants of drug binding to the hERG channel pore. Methods: Atazanavir, remdesivir, ritonavir, lopinavir and favipiravir were docked to in silico models of the pore domain of hERG, derived from cryo-EM structures of hERG and the closely related EAG channel. Results: Atazanavir was readily accommodated in the open hERG channel pore in proximity to the S6 Y652 and F656 residues, consistent with published experimental data implicating these aromatic residues in atazanavir binding to the channel. Lopinavir, ritonavir, and remdesivir were also accommodated in the open channel, making contacts in a model-dependent fashion with S6 aromatic residues and with residues at the base of the selectivity filter/pore helix. The ability of remdesivir (at 30 μM) to inhibit the channel was confirmed using patch-clamp recording. None of these four drugs could be accommodated in the closed channel structure. Favipiravir, a much smaller molecule, was able to fit within the closed channel and could adopt multiple binding poses in the open channel, but with few simultaneous interactions with key binding residues. Only favipiravir and remdesivir showed the potential to interact with lateral pockets below the selectivity filter of the channel. Conclusions: All the antiviral drugs studied here can, in principle, interact with components of the hERG potassium channel canonical binding site, but are likely to differ in their ability to access lateral binding pockets. Favipiravir's small size and relatively paucity of simultaneous interactions may confer reduced hERG liability compared to the other drugs. Experimental structure-function studies are now warranted to validate these observations.
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Affiliation(s)
- Ehab Al-Moubarak
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | | | - Jules C. Hancox
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
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da Rocha AM, Creech J, Thonn E, Mironov S, Herron TJ. Detection of Drug-Induced Torsades de Pointes Arrhythmia Mechanisms Using hiPSC-CM Syncytial Monolayers in a High-Throughput Screening Voltage Sensitive Dye Assay. Toxicol Sci 2020; 173:402-415. [PMID: 31764978 DOI: 10.1093/toxsci/kfz235] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We validated 3 distinct hiPSC-CM cell lines-each of different purity and a voltage sensitive dye (VSD)-based high-throughput proarrhythmia screening assay as a noncore site in the recently completed CiPA Myocyte Phase II Validation Study. Blinded validation was performed using 12 drugs linked to low, intermediate, or high risk for causing Torsades de Pointes (TdP). Commercially sourced hiPSC-CMs were obtained either from Cellular Dynamics International (CDI, Madison, Wisconsin, iCell Cardiomyoyctes2) or Takara Bio (CLS, Cellartis Cardiomyocytes). A third hiPSC-CM cell line (MCH, Michigan) was generated in house. Each cell type had distinct baseline electrophysiological function (spontaneous beat rate, action potential duration, and conduction velocity) and drug responsiveness. Use of VSD and optical mapping enabled the detection of conduction slowing of sodium channel blockers (quinidine, disopyramide, and mexiletine) and drug-induced TdP-like activation patterns (rotors) for some high- and intermediate-risk compounds. Low-risk compounds did not induce rotors in any cell type tested. These results further validate the utility of hiPSC-CMs for predictive proarrhythmia screening and the utility of VSD technology to detect drug-induced APD prolongation, arrhythmias (rotors), and conduction slowing. Importantly, results indicate that different ratios of cardiomyocytes and noncardiomyocytes have important impact on drug response that may be considered during risk assessment of new drugs. Finally, we present the first blinded CiPA hiPSC-CM validation results to simultaneously detect drug-induced conduction slowing, action potential duration prolongation, action potential triangulation, and drug-induced rotors in a proarrhythmia assay.
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Affiliation(s)
- Andre Monteiro da Rocha
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI.,Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI.,CARTOX, LLC-Cardiotoxicity Department, New Hudson, MI 48165
| | - Jeffery Creech
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI.,Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI.,CARTOX, LLC-Cardiotoxicity Department, New Hudson, MI 48165
| | - Ethan Thonn
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI
| | - Sergey Mironov
- Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Todd J Herron
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI.,Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI.,CARTOX, LLC-Cardiotoxicity Department, New Hudson, MI 48165
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Functional evaluation of gene mutations in Long QT Syndrome: strength of evidence from in vitro assays for deciphering variants of uncertain significance. JOURNAL OF CONGENITAL CARDIOLOGY 2020. [DOI: 10.1186/s40949-020-00037-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Genetic screening is now commonplace for patients suspected of having inherited cardiac conditions. Variants of uncertain significance (VUS) in disease-associated genes pose problems for the diagnostician and reliable methods for evaluating VUS function are required. Although function is difficult to interrogate for some genes, heritable channelopathies have established mechanisms that should be amenable to well-validated evaluation techniques.
The cellular electrophysiology techniques of ‘voltage-’ and ‘patch-’ clamp have a long history of successful use and have been central to identifying both the roles of genes involved in different forms of congenital Long QT Syndrome (LQTS) and the mechanisms by which mutations lead to aberrant ion channel function underlying clinical phenotypes. This is particularly evident for KCNQ1, KCNH2 and SCN5A, mutations in which underlie > 90% of genotyped LQTS cases (the LQT1-LQT3 subtypes). Recent studies utilizing high throughput (HT) planar patch-clamp recording have shown it to discriminate effectively between rare benign and pathological variants, studied through heterologous expression of recombinant channels. In combination with biochemical methods for evaluating channel trafficking and supported by biophysical modelling, patch clamp also provides detailed mechanistic insight into the functional consequences of identified mutations. Whilst potentially powerful, patient-specific stem-cell derived cardiomyocytes and genetically modified animal models are currently not well-suited to high throughput VUS study.
Conclusion
The widely adopted 2015 American College of Medical Genetics (ACMG) and Association for Molecular Pathology (AMP) guidelines for the interpretation of sequence variants include the PS3 criterion for consideration of evidence from well-established in vitro or in vivo assays. The wealth of information on underlying mechanisms of LQT1-LQT3 and recent HT patch clamp data support consideration of patch clamp data together (for LQT1 and LQT2) with information from biochemical trafficking assays as meeting the PS3 criterion of well established assays, able to provide ‘strong’ evidence for functional pathogenicity of identified VUS.
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11
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Llopis-Lorente J, Gomis-Tena J, Cano J, Romero L, Saiz J, Trenor B. In Silico Classifiers for the Assessment of Drug Proarrhythmicity. J Chem Inf Model 2020; 60:5172-5187. [PMID: 32786710 DOI: 10.1021/acs.jcim.0c00201] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Drug-induced torsade de pointes (TdP) is a life-threatening ventricular arrhythmia responsible for the withdrawal of many drugs from the market. Although currently used TdP risk-assessment methods are effective, they are expensive and prone to produce false positives. In recent years, in silico cardiac simulations have proven to be a valuable tool for the prediction of drug effects. The objective of this work is to evaluate different biomarkers of drug-induced proarrhythmic risk and to develop an in silico risk classifier. Cellular simulations were performed using a modified version of the O'Hara et al. ventricular action potential model and existing pharmacological data (IC50 and effective free therapeutic plasma concentration, EFTPC) for 109 drugs of known torsadogenic risk (51 positive). For each compound, four biomarkers were tested: Tx (drug concentration leading to a 10% prolongation of the action potential over the EFTPC), TqNet (net charge carried by ionic currents when exposed to 10 times the EFTPC with respect to the net charge in control), Ttriang (triangulation for a drug concentration of 10 times the EFTPC over triangulation in control), and TEAD (drug concentration originating early afterdepolarizations over EFTPC). Receiver operating characteristic (ROC) curves were built for each biomarker to evaluate their individual predictive quality. At the optimal cutoff point, accuracies for Tx, TqNet, Ttriang, and TEAD were 89.9, 91.7, 90.8, and 78.9% respectively. The resulting accuracy of the hERG IC50 test (current biomarker) was 78.9%. When combining Tx, TqNet and Ttriang into a classifier based on decision trees, the prediction improves, achieving an accuracy of 94.5%. The sensitivity analysis revealed that most of the effects on the action potential are mainly due to changes in IKr, ICaL, INaL and IKs. In fact, considering that drugs affect only these four currents, TdP risk classification can be as accurate as when considering effects on the seven main currents proposed by the CiPA initiative. Finally, we built a ready-to-use tool (based on more than 450 000 simulations), which can be used to quickly assess the proarrhythmic risk of a compound. In conclusion, our in silico tool can be useful for the preclinical assessment of TdP-risk and to reduce costs related with new drug development. The TdP risk-assessment tool and the software used in this work are available at https://riunet.upv.es/handle/10251/136919.
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Affiliation(s)
- Jordi Llopis-Lorente
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
| | - Julio Gomis-Tena
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
| | - Jordi Cano
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
| | - Lucía Romero
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
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Zhang Y, Dempsey CE, Hancox JC. Electrophysiological characterization of the modified hERG T potassium channel used to obtain the first cryo-EM hERG structure. Physiol Rep 2020; 8:e14568. [PMID: 33091232 PMCID: PMC7580876 DOI: 10.14814/phy2.14568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/02/2023] Open
Abstract
The voltage-gated hERG (human-Ether-à-go-go Related Gene) K+ channel plays a fundamental role in cardiac action potential repolarization. Loss-of-function mutations or pharmacological inhibition of hERG leads to long QT syndrome, whilst gain-of-function mutations lead to short QT syndrome. A recent open channel cryo-EM structure of hERG represents a significant advance in the ability to interrogate hERG channel structure-function. In order to suppress protein aggregation, a truncated channel construct of hERG (hERGT ) was used to obtain this structure. In hERGT cytoplasmic domain residues 141 to 350 and 871 to 1,005 were removed from the full-length channel protein. There are limited data on the electrophysiological properties of hERGT channels. Therefore, this study was undertaken to determine how hERGT influences channel function at physiological temperature. Whole-cell measurements of hERG current (IhERG ) were made at 37°C from HEK 293 cells expressing wild-type (WT) or hERGT channels. With a standard +20 mV activating command protocol, neither end-pulse nor tail IhERG density significantly differed between WT and hERGT . However, the IhERG deactivation rate was significantly slower for hERGT . Half-maximal activation voltage (V0.5 ) was positively shifted for hERGT by ~+8 mV (p < .05 versus WT), without significant change to the activation relation slope factor. Neither the voltage dependence of inactivation, nor time course of development of inactivation significantly differed between WT and hERGT , but recovery of IhERG from inactivation was accelerated for hERGT (p < .05 versus WT). Steady-state "window" current was positively shifted for hERGT with a modest increase in the window current peak. Under action potential (AP) voltage clamp, hERGT IhERG showed modestly increased current throughout the AP plateau phase with a significant increase in current integral during the AP. The observed consequences for hERGT IhERG of deletion of the two cytoplasmic regions may reflect changes to electrostatic interactions influencing the voltage sensor domain.
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Affiliation(s)
- Yihong Zhang
- School of Physiology and Pharmacology and NeuroscienceBiomedical Sciences BuildingThe University of BristolUniversity WalkBristolUK
| | - Christopher E. Dempsey
- School of BiochemistryBiomedical Sciences BuildingThe University of BristolUniversity WalkBristolUK
| | - Jules C. Hancox
- School of Physiology and Pharmacology and NeuroscienceBiomedical Sciences BuildingThe University of BristolUniversity WalkBristolUK
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Malone K, Hancox JC. QT interval prolongation and Torsades de Pointes with donepezil, rivastigmine and galantamine. Ther Adv Drug Saf 2020; 11:2042098620942416. [PMID: 32874532 PMCID: PMC7436781 DOI: 10.1177/2042098620942416] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 06/19/2020] [Indexed: 01/08/2023] Open
Abstract
Background Acetylcholinesterase inhibitors (AChEis) including donepezil, galantamine and rivastigmine are used to treat Alzheimer's disease (AD). This study aimed to evaluate evidence from the case report literature for an association between these agents and risk of QT interval prolongation and Torsades de Pointes (TdP) arrhythmia. Methods Published literature was mined with predetermined MeSH terms for each of donepezil, galantamine and rivastigmine, to identify cases of QT interval prolongation and TdP. Case reports were analysed using causality scales and a QT interval nomogram. Results A total of 13 case reports were found (10 for donepezil, 2 for galantamine and 1 for rivastigmine) with rate corrected QT interval (QTc) prolongation. Five cases with donepezil exhibited TdP. TdP was not reported in the cases with galantamine and rivastigmine. The use of a QT heart rate nomogram highlighted risk with donepezil compared with the other two drugs and the application of the Naranjo causality scale suggested probable or possible causation for all donepezil cases. All patients had at least two other risk factors for TdP, including modifiable risk factors such as electrolyte disturbances, bradycardia, co-administration of QT prolonging drugs. A number of recent cases involved recent changes in medication. Conclusion Our evaluation of the case report literature suggests that there is evidence for a causal association between donepezil and QTc/TdP risk. Attention to risk factors for QTc prolongation/TdP should be exercised when prescribing donepezil and modifiable risk factors corrected. Owing to the low number of cases with galantamine and rivastigmine, further work is needed to establish whether these drugs may be more suitable than donepezil for patients with other risk factors for TdP.
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Affiliation(s)
- Katie Malone
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol, UK
| | - Jules C Hancox
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol, BS8 1TD, UK
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Gomis-Tena J, Brown BM, Cano J, Trenor B, Yang PC, Saiz J, Clancy CE, Romero L. When Does the IC 50 Accurately Assess the Blocking Potency of a Drug? J Chem Inf Model 2020; 60:1779-1790. [PMID: 32105478 PMCID: PMC7357848 DOI: 10.1021/acs.jcim.9b01085] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Preclinical assessment of drug-induced proarrhythmicity is typically evaluated by the potency of the drug to block the potassium human ether-à-go-go-related gene (hERG) channels, which is currently quantified by the IC50. However, channel block depends on the experimental conditions. Our aim is to improve the evaluation of the blocking potency of drugs by designing experimental stimulation protocols to measure the IC50 that will help to decide whether the IC50 is representative enough. We used the state-of-the-art mathematical models of the cardiac electrophysiological activity to design three stimulation protocols that enhance the differences in the probabilities to occupy a certain conformational state of the channel and, therefore, the potential differences in the blocking effects of a compound. We simulated an extensive set of 144 in silico IKr blockers with different kinetics and affinities to conformational states of the channel and we also experimentally validated our key predictions. Our results show that the IC50 protocol dependency relied on the tested compounds. Some of them showed no differences or small differences on the IC50 value, which suggests that the IC50 could be a good indicator of the blocking potency in these cases. However, others provided highly protocol dependent IC50 values, which could differ by even 2 orders of magnitude. Moreover, the protocols yielding the maximum IC50 and minimum IC50 depended on the drug, which complicates the definition of a "standard" protocol to minimize the influence of the stimulation protocol on the IC50 measurement in safety pharmacology. As a conclusion, we propose the adoption of our three-protocol IC50 assay to estimate the potency to block hERG in vitro. If the IC50 values obtained for a compound are similar, then the IC50 could be used as an indicator of its blocking potency, otherwise kinetics and state-dependent binding properties should be accounted.
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Affiliation(s)
- Julio Gomis-Tena
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Brandon M Brown
- Department of Pharmacology, University of California, Davis, One Shields Avenue, Davis, California 95616-8636, United States
| | - Jordi Cano
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Pei-Chi Yang
- Department of Pharmacology, University of California, Davis, One Shields Avenue, Davis, California 95616-8636, United States
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Colleen E Clancy
- Department of Pharmacology, University of California, Davis, One Shields Avenue, Davis, California 95616-8636, United States
| | - Lucia Romero
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
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15
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Parikh J, Di Achille P, Kozloski J, Gurev V. Global Sensitivity Analysis of Ventricular Myocyte Model-Derived Metrics for Proarrhythmic Risk Assessment. Front Pharmacol 2019; 10:1054. [PMID: 31680938 PMCID: PMC6797832 DOI: 10.3389/fphar.2019.01054] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 08/20/2019] [Indexed: 01/08/2023] Open
Abstract
Multiscale computational models of the heart are being extensively investigated for improved assessment of drug-induced torsades de pointes (TdP) risk, a fatal side effect of many drugs. Model-derived metrics such as action potential duration and net charge carried by ionic currents (qNet) have been proposed as potential candidates for TdP risk stratification after being tested on small datasets. Unlike purely statistical approaches, model-derived metrics are thought to provide mechanism-based classification. In particular, qNet has been recently proposed as a surrogate metric for early afterdepolarizations (EADs), which are known to be cellular triggers of TdP. Analysis of critical model components and of the ion channels that have major impact on model-derived metrics can lead to improvements in the confidence of the prediction. In this paper, we analyze large populations of virtual drugs to systematically examine the influence of different ion channels on model-derived metrics that have been proposed for proarrhythmic risk assessment. We demonstrate via global sensitivity analysis (GSA) that model-derived metrics are most sensitive to different sets of input parameters. Similarly, important differences in sensitivity to specific channel blocks are highlighted when classifying drugs into different risk categories by either qNet or a metric directly based on simulated EADs. In particular, the higher sensitivity of qNet to the block of the late sodium channel might explain why its classification accuracy is better than that of the EAD-based metric, as shown for a small set of known drugs. Our results highlight the need for a better mechanistic interpretation of promising metrics like qNet based on a formal analysis of models. GSA should, therefore, constitute an essential component of the in silico workflow for proarrhythmic risk assessment, as an improved understanding of the structure of model-derived metrics could increase confidence in model-predicted risk.
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Dutta S, Chang KC, Beattie KA, Sheng J, Tran PN, Wu WW, Wu M, Strauss DG, Colatsky T, Li Z. Optimization of an In silico Cardiac Cell Model for Proarrhythmia Risk Assessment. Front Physiol 2017; 8:616. [PMID: 28878692 PMCID: PMC5572155 DOI: 10.3389/fphys.2017.00616] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/09/2017] [Indexed: 12/19/2022] Open
Abstract
Drug-induced Torsade-de-Pointes (TdP) has been responsible for the withdrawal of many drugs from the market and is therefore of major concern to global regulatory agencies and the pharmaceutical industry. The Comprehensive in vitro Proarrhythmia Assay (CiPA) was proposed to improve prediction of TdP risk, using in silico models and in vitro multi-channel pharmacology data as integral parts of this initiative. Previously, we reported that combining dynamic interactions between drugs and the rapid delayed rectifier potassium current (IKr) with multi-channel pharmacology is important for TdP risk classification, and we modified the original O'Hara Rudy ventricular cell mathematical model to include a Markov model of IKr to represent dynamic drug-IKr interactions (IKr-dynamic ORd model). We also developed a novel metric that could separate drugs with different TdP liabilities at high concentrations based on total electronic charge carried by the major inward ionic currents during the action potential. In this study, we further optimized the IKr-dynamic ORd model by refining model parameters using published human cardiomyocyte experimental data under control and drug block conditions. Using this optimized model and manual patch clamp data, we developed an updated version of the metric that quantifies the net electronic charge carried by major inward and outward ionic currents during the steady state action potential, which could classify the level of drug-induced TdP risk across a wide range of concentrations and pacing rates. We also established a framework to quantitatively evaluate a system's robustness against the induction of early afterdepolarizations (EADs), and demonstrated that the new metric is correlated with the cell's robustness to the pro-EAD perturbation of IKr conductance reduction. In summary, in this work we present an optimized model that is more consistent with experimental data, an improved metric that can classify drugs at concentrations both near and higher than clinical exposure, and a physiological framework to check the relationship between a metric and EAD. These findings provide a solid foundation for using in silico models for the regulatory assessment of TdP risk under the CiPA paradigm.
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Affiliation(s)
- Sara Dutta
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Kelly C Chang
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Kylie A Beattie
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Jiansong Sheng
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Phu N Tran
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Wendy W Wu
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Min Wu
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - David G Strauss
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Thomas Colatsky
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
| | - Zhihua Li
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug AdministrationSilver Spring, MD, United States
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Translational science approach for assessment of cardiovascular effects and proarrhythmogenic potential of the beta-3 adrenergic agonist mirabegron. J Pharmacol Toxicol Methods 2017; 87:74-81. [PMID: 28434969 DOI: 10.1016/j.vascn.2017.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 03/30/2017] [Accepted: 04/19/2017] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Translational assessment of cardiac safety parameters is a challenge in clinical development of beta-3 adrenoceptor agonists. The preclinical tools are presented that were used for assessing human safety for mirabegron. METHODS Studies were performed on electrical conductance at ion channels responsible for cardiac repolarization (IKr, IKs, Ito, INa, and ICa,L), on QT-interval, subendocardial APD90, Tpeak-end interval, and arrhythmia's in ventricular dog wedge tissue in vitro and on cardiovascular function (BP, HR, and QTc) in conscious dogs. RESULTS In conscious dogs, mirabegron (0.01-10mg/kg, p.o.) dose-dependently increased HR, reduced SBP but DBP was unchanged. Propranolol blocked the decrease in SBP and attenuated HR increase at 100mg/kg mirabegron. Mirabegron, at 30, 60, or 100mg/kg, p.o., had no significant effect on the QTc interval. In paced dog ventricular wedge, neither mirabegron nor metabolites M5, M11, M12, M14, and M16 prolonged QT, altered transmural dispersion of repolarization, induced premature ventricular contractions, or induced ventricular tachycardia. Mirabegron nor its metabolites inhibited IKr, IKs, Ito INa, or ICa,L at clinically relevant concentrations. DISCUSSION Up to exposure levels well exceeding human clinical exposure no discernible effects on ion channel conductance or on arrhythmogenic parameters in ventricular wedge resulted for mirabegron, or its main metabolites, confirming human cardiac safety findings. In vivo, dose-related increases in HR with effects markedly higher than seen clinically, was mediated in part by cross-activation of beta-1 adrenoceptors. This non-clinical cardiac safety test program therefore proved predictive for human cardiac safety for mirabegron.
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18
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Schlit AF, Delaunois A, Colomar A, Claudio B, Cariolato L, Boev R, Valentin JP, Peters C, Sloan VS, Bentz JWG. Risk of QT prolongation and torsade de pointes associated with exposure to hydroxyzine: re-evaluation of an established drug. Pharmacol Res Perspect 2017; 5:e00309. [PMID: 28480041 PMCID: PMC5415947 DOI: 10.1002/prp2.309] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 01/10/2023] Open
Abstract
Several noncardiac drugs have been linked to cardiac safety concerns, highlighting the importance of post‐marketing surveillance and continued evaluation of the benefit‐risk of long‐established drugs. Here, we examine the risk of QT prolongation and/or torsade de pointes (TdP) associated with the use of hydroxyzine, a first generation sedating antihistamine. We have used a combined methodological approach to re‐evaluate the cardiac safety profile of hydroxyzine, including: (1) a full review of the sponsor pharmacovigilance safety database to examine real‐world data on the risk of QT prolongation and/or TdP associated with hydroxyzine use and (2) nonclinical electrophysiological studies to examine concentration‐dependent effects of hydroxyzine on a range of human cardiac ion channels. Based on a review of pharmacovigilance data between 14th December 1955 and 1st August 2016, we identified 59 reports of QT prolongation and/or TdP potentially linked to hydroxyzine use. Aside from intentional overdose, all cases involved underlying medical conditions or concomitant medications that constituted at least 1 additional risk factor for such events. The combination of cardiovascular disorders plus concomitant treatment of drugs known to induce arrhythmia was identified as the greatest combined risk factor. Parallel patch‐clamp studies demonstrated hydroxyzine concentration‐dependent inhibition of several human cardiac ion channels, including the ether‐a‐go‐go‐related gene (hERG) potassium ion channels. Results from this analysis support the listing of hydroxyzine as a drug with “conditional risk of TdP” and are in line with recommendations to limit hydroxyzine use in patients with known underlying risk factors for QT prolongation and/or TdP.
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Affiliation(s)
| | | | - Aurore Colomar
- UCB Pharma Brussels Belgium.,Present address: Aurore Colomar, Université de Mons Mons Belgium
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19
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Dubois VFS, Smania G, Yu H, Graf R, Chain ASY, Danhof M, Della Pasqua O. Translating QT interval prolongation from conscious dogs to humans. Br J Clin Pharmacol 2017; 83:349-362. [PMID: 27614058 PMCID: PMC5237692 DOI: 10.1111/bcp.13123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 08/08/2016] [Accepted: 08/19/2016] [Indexed: 12/16/2022] Open
Abstract
AIM In spite of screening procedures in early drug development, uncertainty remains about the propensity of new chemical entities (NCEs) to prolong the QT/QTc interval. The evaluation of proarrhythmic activity using a comprehensive in vitro proarrhythmia assay does not fully account for pharmacokinetic-pharmacodynamic (PKPD) differences in vivo. In the present study, we evaluated the correlation between drug-specific parameters describing QT interval prolongation in dogs and in humans. METHODS Using estimates of the drug-specific parameter, data on the slopes of the PKPD relationships of nine compounds with varying QT-prolonging effects (cisapride, sotalol, moxifloxacin, carabersat, GSK945237, SB237376 and GSK618334, and two anonymized NCEs) were analysed. Mean slope estimates varied between -0.98 ms μM-1 and 6.1 ms μM-1 in dogs and -10 ms μM-1 and 90 ms μM-1 in humans, indicating a wide range of effects on the QT interval. Linear regression techniques were then applied to characterize the correlation between the parameter estimates across species. RESULTS For compounds without a mixed ion channel block, a correlation was observed between the drug-specific parameter in dogs and humans (y = -1.709 + 11.6x; R2 = 0.989). These results show that per unit concentration, the drug effect on the QT interval in humans is 11.6-fold larger than in dogs. CONCLUSIONS Together with information about the expected therapeutic exposure, the evidence of a correlation between the compound-specific parameter in dogs and in humans represents an opportunity for translating preclinical safety data before progression into the clinic. Whereas further investigation is required to establish the generalizability of our findings, this approach can be used with clinical trial simulations to predict the probability of QT prolongation in humans.
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Affiliation(s)
- Vincent F. S. Dubois
- Leiden Academic Centre for Drug Research, Division of PharmacologyLeiden UniversityLeidenThe Netherlands
- PharmacometricsGrunenthal GmbHAachenGermany
| | - Giovanni Smania
- Clinical Pharmacology Modelling & SimulationGlaxoSmithKline, Stockley ParkUxbridgeUK
| | - Huixin Yu
- Leiden Academic Centre for Drug Research, Division of PharmacologyLeiden UniversityLeidenThe Netherlands
| | - Ramona Graf
- Clinical Pharmacology Modelling & SimulationGlaxoSmithKline, Stockley ParkUxbridgeUK
| | - Anne S. Y. Chain
- Leiden Academic Centre for Drug Research, Division of PharmacologyLeiden UniversityLeidenThe Netherlands
| | - Meindert Danhof
- Leiden Academic Centre for Drug Research, Division of PharmacologyLeiden UniversityLeidenThe Netherlands
| | - Oscar Della Pasqua
- Clinical Pharmacology Modelling & SimulationGlaxoSmithKline, Stockley ParkUxbridgeUK
- Clinical Pharmacology & TherapeuticsUCLLondonUK
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Shum AMY, Che H, Wong AOT, Zhang C, Wu H, Chan CWY, Costa K, Khine M, Kong CW, Li RA. A Micropatterned Human Pluripotent Stem Cell-Based Ventricular Cardiac Anisotropic Sheet for Visualizing Drug-Induced Arrhythmogenicity. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1602448. [PMID: 27805726 DOI: 10.1002/adma.201602448] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/02/2016] [Indexed: 06/06/2023]
Abstract
A novel cardiomimetic biohybrid material, termed as the human ventricular cardiac anisotropic sheet (hvCAS) is reported. Well-characterized human pluripotent stem-cell-derived ventricular cardiomyocytes are strategically aligned to reproduce key electrophysiological features of native human ventricle, which, along with specific selection criteria, allows for a direct visualization of arrhythmic spiral re-entry and represents a revolutionary tool to assess preclinical drug-induced arrhythmogenicity.
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Affiliation(s)
- Angie M Y Shum
- Stem Cell & Regenerative Medicine Consortium, LKS Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong
| | - Hui Che
- Stem Cell & Regenerative Medicine Consortium, LKS Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong
| | - Andy On-Tik Wong
- Stem Cell & Regenerative Medicine Consortium, LKS Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong
| | - Chenzi Zhang
- Stem Cell & Regenerative Medicine Consortium, LKS Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong
| | - Hongkai Wu
- Biomedical Engineering, Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong
| | - Camie W Y Chan
- Novoheart Ltd., Hong Kong Science Park, Shatin, Hong Kong
| | - Kevin Costa
- Icahn School of Medicine at Mount Sinai, Manhattan, NYC, 10029-5674, USA
| | - Michelle Khine
- Biomedical Engineering, University of California at Irvine, Irvine, CA, 92697-2715, USA
| | - Chi-Wing Kong
- Stem Cell & Regenerative Medicine Consortium, LKS Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong
| | - Ronald A Li
- Dr. Li Dak-Sum Research Centre, University of Hong Kong, Pokfulam, Hong Kong
- Ming-Wai Lau Centre for Reparative Medicine, Karolinska Institutet, Stockholm, 17177, Sweden
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Dubois VFS, Casarotto E, Danhof M, Della Pasqua O. Pharmacokinetic-pharmacodynamic modelling of drug-induced QTc interval prolongation in man: prediction from in vitro human ether-à-go-go-related gene binding and functional inhibition assays and conscious dog studies. Br J Pharmacol 2016; 173:2819-32. [PMID: 27427789 DOI: 10.1111/bph.13558] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Functional measures of human ether-à-go-go-related gene (hERG; Kv 11.1) channel inhibition have been prioritized as an in vitro screening tool for candidate molecules. However, it is unclear how these results can be translated to humans. Here, we explore how data on drug binding and functional inhibition in vitro relate to QT prolongation in vivo. Using cisapride, sotalol and moxifloxacin as paradigm compounds, we assessed the relationship between drug concentrations, binding, functional measures and in vivo effects in preclinical species and humans. EXPERIMENTAL APPROACH Pharmacokinetic-pharmacodynamic modelling was used to characterize the drug effects in hERG functional patch clamp, hERG radio-labelled dofetilide displacement experiments and QT interval in conscious dogs. Data were analysed in parallel to identify potential correlations between pharmacological activity in vitro and in vivo. KEY RESULTS An Emax model could not be used due to large variability in the functional patch clamp assay. Dofetilide displacement revealed that binding curves are unrelated to the in vivo potency estimates for QTc prolongation in dogs and humans. Mean in vitro potency estimates ranged from 99.9 nM for cisapride to 1030 μM for moxifloxacin. CONCLUSIONS AND IMPLICATIONS The lack of standardized protocols for in vitro assays leads to significant differences in experimental conditions, making the assessment of in vitro-in vivo correlations unreliable. Identification of an accurate safety window during the screening of candidate molecules requires a quantitative framework that disentangles system- from drug-specific properties under physiological conditions, enabling translation of the results to humans. Similar considerations will be relevant for the comprehensive in vitro pro-arrhythmia assay initiative.
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Affiliation(s)
- V F S Dubois
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - E Casarotto
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - M Danhof
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - O Della Pasqua
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands. .,Clinical Pharmacology Modelling and Simulation, GlaxoSmithKline, Uxbridge, UK. .,Clinical Pharmacology and Therapeutics, School of Life and Medical Sciences, University College London, London, UK.
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Comprehensive in vitro Proarrhythmia Assay (C i PA): Pending issues for successful validation and implementation. J Pharmacol Toxicol Methods 2016; 81:21-36. [DOI: 10.1016/j.vascn.2016.05.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 12/29/2022]
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Dubois VFS, de Witte WEA, Visser SAG, Danhof M, Della Pasqua O. Assessment of Interspecies Differences in Drug-Induced QTc Interval Prolongation in Cynomolgus Monkeys, Dogs and Humans. Pharm Res 2015; 33:40-51. [PMID: 26553352 PMCID: PMC4689776 DOI: 10.1007/s11095-015-1760-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 07/16/2015] [Indexed: 11/30/2022]
Abstract
Background and Purpose The selection of the most suitable animal species and subsequent translation of the concentration-effect relationship to humans are critical steps for accurate assessment of the pro-arrhythmic risk of candidate molecules. The objective of this investigation was to assess quantitatively the differences in the QTc prolonging effects of moxifloxacin between cynomolgus monkeys, dogs and humans. The impact of interspecies differences is also illustrated for a new candidate molecule. Experimental Approach Pharmacokinetic data and ECG recordings from pre-clinical protocols in monkeys and dogs and from a phase I trial in healthy subjects were identified for the purpose of this analysis. A previously established Bayesian model describing the combined effect of heart rate, circadian variation and drug effect on the QT interval was used to describe the pharmacokinetic-pharmacodynamic relationships. The probability of a ≥10 ms increase in QT was derived as measure of the pro-arrhythmic effect. Key Results For moxifloxacin, the concentrations associated with a 50% probability of QT prolongation ≥10 ms (Cp50) varied from 20.3 to 6.4 and 2.6 μM in dogs, monkeys and humans, respectively. For NCE05, these values were 0.4 μM vs 2.0 μM for monkeys and humans, respectively. Conclusions and Implications Our findings reveal significant interspecies differences in the QT-prolonging effect of moxifloxacin. In addition to the dissimilarity in pharmacokinetics across species, it is likely that differences in pharmacodynamics also play an important role. It appears that, regardless of the animal model used, a translation function is needed to predict concentration-effect relationships in humans.
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Affiliation(s)
- V F S Dubois
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - W E A de Witte
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - S A G Visser
- Global DMPK, AstraZeneca R&D, Sodertalje, Sweden
| | - M Danhof
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - O Della Pasqua
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands. .,Clinical Pharmacology Modelling & Simulation, GlaxoSmithKline, Stockley Park, Uxbridge, UK. .,Clinical Pharmacology & Therapeutics, University College London, London, UK.
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Fermini B, Hancox JC, Abi-Gerges N, Bridgland-Taylor M, Chaudhary KW, Colatsky T, Correll K, Crumb W, Damiano B, Erdemli G, Gintant G, Imredy J, Koerner J, Kramer J, Levesque P, Li Z, Lindqvist A, Obejero-Paz CA, Rampe D, Sawada K, Strauss DG, Vandenberg JI. A New Perspective in the Field of Cardiac Safety Testing through the Comprehensive In Vitro Proarrhythmia Assay Paradigm. ACTA ACUST UNITED AC 2015; 21:1-11. [PMID: 26170255 DOI: 10.1177/1087057115594589] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 06/11/2015] [Indexed: 12/31/2022]
Abstract
For the past decade, cardiac safety screening to evaluate the propensity of drugs to produce QT interval prolongation and Torsades de Pointes (TdP) arrhythmia has been conducted according to ICH S7B and ICH E14 guidelines. Central to the existing approach are hERG channel assays and in vivo QT measurements. Although effective, the present paradigm carries a risk of unnecessary compound attrition and high cost, especially when considering costly thorough QT (TQT) studies conducted later in drug development. The C: omprehensive I: n Vitro P: roarrhythmia A: ssay (CiPA) initiative is a public-private collaboration with the aim of updating the existing cardiac safety testing paradigm to better evaluate arrhythmia risk and remove the need for TQT studies. It is hoped that CiPA will produce a standardized ion channel assay approach, incorporating defined tests against major cardiac ion channels, the results of which then inform evaluation of proarrhythmic actions in silico, using human ventricular action potential reconstructions. Results are then to be confirmed using human (stem cell-derived) cardiomyocytes. This perspective article reviews the rationale, progress of, and challenges for the CiPA initiative, if this new paradigm is to replace existing practice and, in time, lead to improved and widely accepted cardiac safety testing guidelines.
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Affiliation(s)
| | - Jules C Hancox
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| | - Najah Abi-Gerges
- Translational Safety, Drug Safety and Metabolism, Innovative Medicines and Early Development, AstraZeneca R&D, Macclesfield, UK AnaBios Corporation, San Diego, CA, USA
| | - Matthew Bridgland-Taylor
- Discovery Sciences, Innovative Medicines and Early Development, AstraZeneca R&D, Macclesfield, UK
| | | | - Thomas Colatsky
- Division of Applied Regulatory Science, CDER, US Food and Drug Administration, Silver Spring, MD, USA
| | | | | | - Bruce Damiano
- Global Safety Pharmacology, Discovery Sciences, Janssen Research & Development LLC, Spring House, PA, USA
| | - Gul Erdemli
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Inc, Cambridge, MA, USA
| | - Gary Gintant
- Department of Integrative Pharmacology, Integrated Sciences & Technology, AbbVie, North Chicago, IL, USA
| | - John Imredy
- Department of Safety Assessment, Merck & Co, Kenilworth, NJ, USA
| | - John Koerner
- Division of Cardiovascular and Renal Products, CDER, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - James Kramer
- ChanTest, A Charles River Company, Cleveland, OH, USA
| | - Paul Levesque
- Bristol Myers Squibb Research & Development, Princeton, NJ, USA
| | - Zhihua Li
- Division of Applied Regulatory Science, CDER, US Food and Drug Administration, Silver Spring, MD, USA
| | | | | | - David Rampe
- Preclinical Safety, Sanofi, Bridgewater, NJ, USA
| | - Kohei Sawada
- Global Cardiovascular Assessment, Eisai Co., Ltd., Ibaraki, Japan
| | - David G Strauss
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, St Vincent's Clinical School, University of NSW, Darlinghurst, NSW, Australia
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Polak S, Pugsley MK, Stockbridge N, Garnett C, Wiśniowska B. Early Drug Discovery Prediction of Proarrhythmia Potential and Its Covariates. AAPS JOURNAL 2015; 17:1025-32. [PMID: 25940083 PMCID: PMC4476985 DOI: 10.1208/s12248-015-9773-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/16/2015] [Indexed: 12/26/2022]
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Dumotier BM. Republished: A straightforward guide to the basic science behind arrhythmogenesis. Postgrad Med J 2015; 91:221-9. [DOI: 10.1136/postgradmedj-2014-305647rep] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Effects of proarrhythmic drugs on relaxation time and beating pattern in rat engineered heart tissue. Basic Res Cardiol 2014; 109:436. [PMID: 25209140 PMCID: PMC4160570 DOI: 10.1007/s00395-014-0436-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 08/27/2014] [Accepted: 08/29/2014] [Indexed: 11/24/2022]
Abstract
The assessment of proarrhythmic risks of drugs remains challenging. To evaluate
the suitability of rat engineered heart tissue (EHT) for detecting proarrhythmic effects. We monitored drug effects on spontaneous contractile activity and, in selected cases, on action potentials (sharp microelectrode) and Ca2+ transients (Fura-2) and contraction under electrical pacing. The Ito-blocker inhibitor 4-aminopyridine increased action potential duration and T2 and caused aftercontractions, which were abolished by inhibitors of ryanodine receptors (RyR2; JTV-519) or sodium calcium exchanger (NCX; SEA0400). 77 Drugs were then tested at 1-10-100× free therapeutic plasma concentrations (FTPC): Inhibitors of IKr, IKs, Ito, antiarrhythmics (8), drugs withdrawn from market for torsades des pointes arrhythmias (TdP, 5), drugs with measurable (7) or isolated TdP incidence (13), drugs considered safe (14), 28 new chemical entities (NCE). Inhibitors of IKr or IKs had no effect alone, but substantially prolonged relaxation time (T2) when combined at high concentration. 15/33 drugs associated with TdP and 6/14 drugs considered non-torsadogenic (cibenzoline, diltiazem, ebastine, ketoconazole, moxifloxacin, and phenytoin) induced concentration-dependent T2 prolongations (10-100× FTPC). Bepridil, desipramine, imipramine, thioridazine, and erythromycin induced irregular beating. Three NCE prolonged T2, one reduced force. Drugs inhibiting repolarization prolong relaxation in rat EHTs and cause aftercontractions involving RyR2 and NCX. Insensitivity to IKr inhibitors makes rat EHTs unsuitable as general proarrhythmia screen, but favors detection of effects on Ito, IKs + Ito or IKs + IKr. Screening a large panel of drugs suggests that effects on these currents, in addition to IKr, are more common than anticipated.
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Hancox JC, Hasnain M, Vieweg WVR, Gysel M, Methot M, Baranchuk A. Erythromycin, QTc interval prolongation, and torsade de pointes: Case reports, major risk factors and illness severity. Ther Adv Infect Dis 2014; 2:47-59. [PMID: 25165555 DOI: 10.1177/2049936114527744] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES Erythromycin is a macrolide antibiotic that is widely used for various infections of the upper respiratory tract, skin, and soft tissue. Similar to other macrolides (clarithromycin, azithromycin), erythromycin has been linked to QTc interval prolongation and torsade de pointes (TdP) arrhythmia. We sought to identify factors that link to erythromycin-induced/associated QTc interval prolongation and TdP. METHODS AND RESULTS In a critical evaluation of case reports, we found 29 cases: 22 women and 7 men (age range 18-95 years). With both oral and intravenous erythromycin administration, there was no significant relationship between dose and QTc interval duration in these cases. Notably, all patients had severe illness. Other risk factors included female sex, older age, presence of heart disease, concomitant administration of either other QTc prolonging drugs or agents that were substrates for or inhibitors of CYP3A4. Most patients had at least two risk factors. CONCLUSIONS On the basis of case report evaluation, we believe that major risk factors for erythromycin-associated TdP are female sex, heart disease and old age, particularly against a background of severe illness. Coadministration of erythromycin with other drugs that inhibit or are metabolized by CYP3A4 or with QTc prolonging drugs should be avoided in this setting.
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Affiliation(s)
| | - Mehrul Hasnain
- Department of Psychiatry, Memorial University, St John's, Newfoundland, Canada
| | - W Victor R Vieweg
- Departments of Psychiatry and Internal Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Michael Gysel
- School of Medicine, Department of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
| | - Michelle Methot
- Department of Pharmacy, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
| | - Adrian Baranchuk
- School of Medicine, Department of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
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Kogut C, Crouse EB, Vieweg WVR, Hasnain M, Baranchuk A, Digby GC, Koneru JN, Fernandez A, Deshmukh A, Hancox JC, Pandurangi AK. Selective serotonin reuptake inhibitors and torsade de pointes: new concepts and new directions derived from a systematic review of case reports. Ther Adv Drug Saf 2014; 4:189-98. [PMID: 25114780 DOI: 10.1177/2042098613492366] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE In the light of the recent United States Food and Drug Administration (FDA) warning to clinicians on using previously approved doses of citalopram because of the purported higher risk of torsade de pointes (TdP), we pursued the broader question: are selective serotonin reuptake inhibitor (SSRI) antidepressant agents as a group unsafe because they might induce QTc interval prolongation and TdP? METHOD We reviewed the literature and found only 15 case reports (6 of fluoxetine, 1 of sertraline and 8 of citalopram) of SSRI-associated QTc interval prolongation linking to TdP. RESULTS A total of 13 cases contained sufficient information for analysis. In the setting of TdP, QTc interval prolongation does not clearly relate to SSRI dose. CONCLUSION Applying conventional statistics as the FDA does may not be the best tool to study this phenomenon because SSRI-associated TdP is a very rare event and hence best understood as an 'extreme outlier'. Despite the limitations inherent in case report material, case reports on drug-associated QTc interval prolongation and TdP provide valuable information that should be considered along with other sources of information for clinical guidance.
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Affiliation(s)
- Christopher Kogut
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
| | | | - W Victor R Vieweg
- Departments of Psychiatry and Internal Medicine, Virginia Commonwealth University, 17 Runswick Drive, Richmond, VA 23238-5414, USA
| | - Mehrul Hasnain
- Department of Psychiatry, Memorial University, St John's, Newfoundland, Canada
| | - Adrian Baranchuk
- Department of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
| | - Geneviève C Digby
- Department of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
| | - Jayanthi N Koneru
- Department of Internal Medicine, Division of Cardiology and Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, VA, USA
| | - Antony Fernandez
- Department of Psychiatry, Virginia Commonwealth University, and Psychiatry Service, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Anand Deshmukh
- Department of Cardiovascular Medicine, The Cardiac Center of Creighton University, Omaha, NE, USA
| | - Jules C Hancox
- School of Physiology and Pharmacology and Cardiovascular Research Laboratories, Medical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Ananda K Pandurangi
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
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Doggrell SA, Hancox JC. Cardiac safety concerns for domperidone, an antiemetic and prokinetic, and galactogogue medicine. Expert Opin Drug Saf 2013; 13:131-8. [PMID: 24147629 DOI: 10.1517/14740338.2014.851193] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Domperidone is a dopamine D2-receptor antagonist developed as an antiemetic and prokinetic agent. Oral domperidone is not approved in the United States, but it is used in many countries to treat nausea and vomiting, gastroparesis and as a galactogogue (to promote lactation). The US Food and Drug Administration (FDA) have issued a warning about the cardiac safety of domperidone. AREAS COVERED The authors undertook a review of the cardiac safety of oral domperidone. EXPERT OPINION The data from preclinical studies are unambiguous in identifying domperidone as able to produce marked hERG channel inhibition and action potential prolongation at clinically relevant concentrations. The compound's propensity to augment instability of action potential duration and action potential triangulation are also indicative of proarrhythmic potential. Domperidone should not be administered to subjects with pre-existing QT prolongation/LQTS, subjects receiving drugs that inhibit CYP3A4, subjects with electrolyte abnormalities or with other risk factors for QT-prolongation. With these provisos, it is possible that domperidone may be used as a galactogogue without direct risk to healthy breast feeding women, but more safety information should be sought in this situation. Also, more safety information is required regarding risk to breast feeding infants before domperidone is routinely used in gastroparesis or gastroesphageal reflux in children.
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Affiliation(s)
- Sheila A Doggrell
- Queensland University of Technology, School of Biomedical Sciences, Faculty of Health , Brisbane, QLD4002 , Australia +61 7 3138 2015 ; +61 7 3138 1534 ;
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The Lambeth Conventions (II): Guidelines for the study of animal and human ventricular and supraventricular arrhythmias. Pharmacol Ther 2013; 139:213-48. [DOI: 10.1016/j.pharmthera.2013.04.008] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 04/01/2013] [Indexed: 12/17/2022]
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Vieweg WVR, Hasnain M, Hancox JC, Baranchuk A, Digby GC, Kogut C, Crouse ELB, Koneru JN, Deshmukh A, Pandurangi AK. Risperidone, QTc interval prolongation, and torsade de pointes: a systematic review of case reports. Psychopharmacology (Berl) 2013; 228:515-24. [PMID: 23812796 DOI: 10.1007/s00213-013-3192-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/12/2013] [Indexed: 01/08/2023]
Abstract
RATIONALE A recent publication asserted that even low-dose risperidone may induce corrected QT (QTc) interval prolongation up to 500 ms without drug-induced IKr blockade. We seek to better understand the complexity of any link between risperidone-induced/associated QTc interval prolongation and torsade de pointes (TdP). OBJECTIVES The objective of this study is to systematically analyze all available case reports of risperidone, QTc interval prolongation, and/or TdP. METHOD We identify case reports using PubMed, Medline, EMBASE, and Cochrane. RESULTS Of the 15 cases found, nine were adult women (ages 31, 33, 34, 37, 47, "elderly", 77, 84, and 87 years) and one was a teenager. There were four men (ages 28, 29, 29, and 46 years) and one preadolescent boy. Besides risperidone administration or overdose, traditional risk factors for QTc interval prolongation and TdP included female sex (n = 10), older age (n = 4), heart disease (n = 3), hypokalemia (n = 2), bradycardia (n = 1), liver disease (n = 1), QTc interval prolonging drugs other than risperidone (n = 8), and metabolic inhibitors (n = 2). TdP occurred in four cases. Six patients died, and three deaths were probably related to TdP. CONCLUSION Risperidone (when properly prescribed in patients free of other risk factors for QTc interval prolongation and TdP) is a relatively safe drug. Conventional statistics can neither predict the individual patient who will experience TdP nor determine the relationship of drug dose to QTc interval prolongation and TdP. Narrative medicine using a case report format appears to be an alternative and valuable additional approach to advance our understanding of this relationship and to reduce risks.
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Affiliation(s)
- W Victor R Vieweg
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA,
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Vieweg WVR, Hasnain M, Howland RH, Clausen T, Koneru JN, Kogut C, Crouse ELB, Hancox JC, Fernandez A, Pandurangi AK. Methadone, QTc interval prolongation and torsade de pointes: Case reports offer the best understanding of this problem. Ther Adv Psychopharmacol 2013; 3:219-32. [PMID: 24167694 PMCID: PMC3805428 DOI: 10.1177/2045125312469982] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We reviewed the literature and found 31 adult cases and 1 newborn case of methadone-associated QTc interval prolongation and/or torsade de pointes (TdP). Parametric statistics may not be useful in studying this issue because methadone-associated TdP is a very rare event and, hence, "an extreme outlier" consistent with scalable randomness. We may have to rely upon narrative medicine in the form of case reports with all its limitations and hazards to provide our best understanding. We report risk factors for methadone-associated QTc interval prolongation and TdP based on review of published case reports. We believe both drug manufacturers and the FDA would better serve our patients and inform clinicians if they more readily reported drug-induced outliers such as methadone-associated TdP using a case report format.
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Affiliation(s)
- W Victor R Vieweg
- Departments of Psychiatry and Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
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Vieweg WVR. Clarithromycin, QTc interval prolongation and torsades de pointes: the need to study case reports. Ther Adv Infect Dis 2013; 1:121-38. [PMID: 25165548 PMCID: PMC4040724 DOI: 10.1177/2049936113497203] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The manufacturers of clarithromycin sought a drug similar in efficacy to erythromycin but with a superior side-effect profile. They generally achieved this outcome, but postmarketing findings identified a series of reports linking clarithromycin to QTc interval prolongation and torsades de pointes (TdP) ultimately leading to a Black Box Warning. We sought to clarify risk factors associated with TdP among case reports of patients receiving clarithromycin linked to QTc interval prolongation and TdP. METHODS AND RESULTS In a detailed literature search, we found 15 women, five men, and one boy meeting our search criteria. Among the 17 adults with reported clarithromycin dose and concurrent QTc interval measurement, we found no statistically significant relationship between clarithromycin dose and QTc interval duration. This did not change for the adults who developed TdP. Among adults, major risk factors were female sex (15), old age (11) and heart disease (17). A total of eight adult subjects had all three major risk factors and 14 of the 20 adults had at least two major risk factors. All adult subjects had at least two risk factors besides clarithromycin. A total of four of the 20 adults received cisapride and three received disopyramide. Three adults were considered to suffer from some aspect of the congenital long QT syndrome. CONCLUSIONS We believe that the risk factor description for this drug should be refined to emphasize the major risk factors of (1) female sex, (2) old age and (3) heart disease.
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Affiliation(s)
- W. Victor R. Vieweg
- Departments of Psychiatry and Internal Medicine, Virginia Commonwealth University, 17 Runswick Drive, Richmond, VA 23238-5414, USA
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Doggrell SA, Hancox JC. Cardiac safety concerns for ondansetron, an antiemetic commonly used for nausea linked to cancer treatment and following anaesthesia. Expert Opin Drug Saf 2013; 12:421-31. [DOI: 10.1517/14740338.2013.780026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Valerio LG, Balakrishnan S, Fiszman ML, Kozeli D, Li M, Moghaddam S, Sadrieh N. Development of cardiac safety translational tools for QT prolongation and torsade de pointes. Expert Opin Drug Metab Toxicol 2013; 9:801-15. [DOI: 10.1517/17425255.2013.783819] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Guns PJ, Johnson DM, Van Op den Bosch J, Weltens E, Lissens J. The electro-mechanical window in anaesthetized guinea pigs: a new marker in screening for Torsade de Pointes risk. Br J Pharmacol 2012; 166:689-701. [PMID: 22122450 DOI: 10.1111/j.1476-5381.2011.01795.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE QT prolongation is commonly used as a surrogate marker for Torsade de Pointes (TdP) risk of non-cardiovascular drugs. However, use of this indirect marker often leads to misinterpretation of the realistic TdP risk, as tested compounds may cause QT prolongation without evoking TdP in humans. A negative electro-mechanical (E-M) window has recently been proposed as an alternative risk marker for TdP in a canine LQT1 model. Here, we evaluated the E-M window in anaesthetized guinea pigs as a screening marker for TdP in humans. EXPERIMENTAL APPROACH The effects of various reference drugs and changes in body temperature on the E-M window were assessed in instrumented guinea pigs. The E-M window was defined as the delay between the duration of the electrical (QT interval) and mechanical (QLVP(end) ) systole. KEY RESULTS Drugs with known TdP liability (quinidine, haloperidol, domperidone, terfenadine, thioridazine and dofetilide), but not those with no TdP risk in humans (salbutamol and diltiazem) consistently decreased the E-M window. Interestingly, drugs with known clinical QT prolongation, but with low risk for TdP (amiodarone, moxifloxacin and ciprofloxacin) did not decrease the E-M window. Furthermore, the E-M window was minimally affected by changes in heart rate or body temperature. CONCLUSIONS AND IMPLICATIONS A decreased E-M window was consistently observed with drugs already known to have high TdP risk, but not with drugs with low or no TdP risk. These results suggest that the E-M window in anaesthetized guinea pigs is a risk marker for TdP in humans.
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Affiliation(s)
- P-J Guns
- Bio-Plus Safety Pharmacology, Bio-Plus Services, Mol, Belgium.
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Higgins J, Cartwright ME, Templeton AC. Progressing preclinical drug candidates: strategies on preclinical safety studies and the quest for adequate exposure. Drug Discov Today 2012; 17:828-36. [DOI: 10.1016/j.drudis.2012.03.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 02/16/2012] [Accepted: 03/30/2012] [Indexed: 11/17/2022]
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Vandenberg JI, Perry MD, Perrin MJ, Mann SA, Ke Y, Hill AP. hERG K+ Channels: Structure, Function, and Clinical Significance. Physiol Rev 2012; 92:1393-478. [DOI: 10.1152/physrev.00036.2011] [Citation(s) in RCA: 463] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The human ether-a-go-go related gene (hERG) encodes the pore-forming subunit of the rapid component of the delayed rectifier K+ channel, Kv11.1, which are expressed in the heart, various brain regions, smooth muscle cells, endocrine cells, and a wide range of tumor cell lines. However, it is the role that Kv11.1 channels play in the heart that has been best characterized, for two main reasons. First, it is the gene product involved in chromosome 7-associated long QT syndrome (LQTS), an inherited disorder associated with a markedly increased risk of ventricular arrhythmias and sudden cardiac death. Second, blockade of Kv11.1, by a wide range of prescription medications, causes drug-induced QT prolongation with an increase in risk of sudden cardiac arrest. In the first part of this review, the properties of Kv11.1 channels, including biogenesis, trafficking, gating, and pharmacology are discussed, while the second part focuses on the pathophysiology of Kv11.1 channels.
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Affiliation(s)
- Jamie I. Vandenberg
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Matthew D. Perry
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Mark J. Perrin
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Stefan A. Mann
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Ying Ke
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Adam P. Hill
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
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Möller C. Keeping the rhythm: hERG and beyond in cardiovascular safety pharmacology. Expert Rev Clin Pharmacol 2012; 3:321-9. [PMID: 22111613 DOI: 10.1586/ecp.10.24] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Following its involvement in life-threatening cardiac arrhythmias, the catchword 'hERG' has become infamous in the drug discovery community. The blockade of the ion channel coded by the human ether-á-go-go-related gene (hERG) has been correlated to a prolongation of the QT interval in the ECG, which again is correlated to a potential risk of a life-threatening polymorphic ventricular tachycardia - torsades de pointes (TdP). Therefore, in vitro investigations for blockade of this ion channel have become a standard, starting early in most drug discovery projects and often accompanying the whole project; at some stage, scientists in many medicinal chemistry programs have to deal with hERG channel liabilities. Data for the compound effects on hERG channel activity are generally part of the safety pharmacology risk assessment in regulatory submissions and, at this stage, are ideally conducted in compliance with good laboratory practice. With the withdrawal of clobutinol from the market, owing to its perceived risk of introducing TdP, the importance of the hERG channel has very recently been reconfirmed. Despite being of such importance for drug discovery, the relevance and impact of hERG data are sometimes misinterpreted, as there are drugs that block the hERG-coded ion channel but do not cause TdP, and drugs that cause TdP but do not block the hERG channel. This review aims to provide an overview of TdP, including the cardiac action potential and the ion channels involved in it, as well as on the relevance and interpretation of in vitro hERG channel data and their impact for drug discovery projects. Finally, novel cardiac safety test systems beyond in vitro hERG channel screening are discussed.
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Affiliation(s)
- Clemens Möller
- Evotec AG, Discovery Alliances, Schnackenburgallee 114, Hamburg, Germany.
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Satin LZ, Durham TA, Turner JR. Assessing a Drug’s Proarrhythmic Liability: An Overview of Computer Simulation Modeling, Nonclinical Assays, and the Thorough QT/QTc Study. ACTA ACUST UNITED AC 2011. [DOI: 10.1177/009286151104500315] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Pasquié JL, Thireau J, Davy JM, Le Guennec JY, Richard S. Médicaments anti-arythmiques : Présent et futur. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2011. [DOI: 10.1016/s1878-6480(11)70394-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Curtis MJ. A novel adult human ventricle slice preparation for cardiac drug discovery and safety pharmacology. Cardiovasc Res 2011; 93:10-1. [PMID: 22049535 DOI: 10.1093/cvr/cvr293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
The drug-induced long QT syndrome is a distinct clinical entity that has evolved from an electrophysiologic curiosity to a centerpiece in drug regulation and development. This evolution reflects an increasing recognition that a rare adverse drug effect can profoundly upset the balance between benefit and risk that goes into the prescription of a drug by an individual practitioner as well as the approval of a new drug entity by a regulatory agency. This review will outline how defining the central mechanism, block of the cardiac delayed-rectifier potassium current I(Kr), has contributed to defining risk in patients and in populations. Models for studying risk, and understanding the way in which clinical risk factors modulate cardiac repolarization at the molecular level are discussed. Finally, the role of genetic variants in modulating risk is described.
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Affiliation(s)
- Prince Kannankeril
- Oates Institute for Experimental Therapeutics, Vanderbilt University School of Medicine, Nashville, TN 37232-0575, USA
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Thireau J, Pasquié JL, Martel E, Le Guennec JY, Richard S. New drugs vs. old concepts: a fresh look at antiarrhythmics. Pharmacol Ther 2011; 132:125-45. [PMID: 21420430 DOI: 10.1016/j.pharmthera.2011.03.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/01/2011] [Indexed: 01/10/2023]
Abstract
Common arrhythmias, particularly atrial fibrillation (AF) and ventricular tachycardia/fibrillation (VT/VF) are a major public health concern. Classic antiarrhythmic (AA) drugs for AF are of limited effectiveness, and pose the risk of life-threatening VT/VF. For VT/VF, implantable cardiac defibrillators appear to be the unique, yet unsatisfactory, solution. Very few AA drugs have been successful in the last few decades, due to safety concerns or limited benefits in comparison to existing therapy. The Vaughan-Williams classification (one drug for one molecular target) appears too restrictive in light of current knowledge of molecular and cellular mechanisms. New AA drugs such as atrial-specific and/or multichannel blockers, upstream therapy and anti-remodeling drugs, are emerging. We focus on the cellular mechanisms related to abnormal Na⁺ and Ca²⁺ handling in AF, heart failure, and inherited arrhythmias, and on novel strategies aimed at normalizing ionic homeostasis. Drugs that prevent excessive Na⁺ entry (ranolazine) and aberrant diastolic Ca²⁺ release via the ryanodine receptor RyR2 (rycals, dantrolene, and flecainide) exhibit very interesting antiarrhythmic properties. These drugs act by normalizing, rather than blocking, channel activity. Ranolazine preferentially blocks abnormal persistent (vs. normal peak) Na⁺ currents, with minimal effects on normal channel function (cell excitability, and conduction). A similar "normalization" concept also applies to RyR2 stabilizers, which only prevent aberrant opening and diastolic Ca²⁺ leakage in diseased tissues, with no effect on normal function during systole. The different mechanisms of action of AA drugs may increase the therapeutic options available for the safe treatment of arrhythmias in a wide variety of pathophysiological situations.
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Affiliation(s)
- Jérôme Thireau
- Inserm U1046 Physiologie & Médecine Expérimentale du Cœur et des Muscles, Université Montpellier-1, Université Montpellier-2, 34295 Montpellier Cedex 5, France
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Panyasing Y, Kijtawornrat A, del Rio C, Carnes C, Hamlin RL. Uni- or bi-ventricular hypertrophy and susceptibility to drug-induced torsades de pointes. J Pharmacol Toxicol Methods 2010; 62:148-56. [DOI: 10.1016/j.vascn.2010.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Accepted: 04/16/2010] [Indexed: 11/28/2022]
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Milnes JT, Witchel HJ, Leaney JL, Leishman DJ, Hancox JC. Investigating dynamic protocol-dependence of hERG potassium channel inhibition at 37°C: Cisapride versus dofetilide. J Pharmacol Toxicol Methods 2010; 61:178-91. [DOI: 10.1016/j.vascn.2010.02.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 02/03/2010] [Accepted: 02/11/2010] [Indexed: 01/08/2023]
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Ahrens-Nicklas RC, Christini DJ. Anthropomorphizing the mouse cardiac action potential via a novel dynamic clamp method. Biophys J 2010; 97:2684-92. [PMID: 19917221 DOI: 10.1016/j.bpj.2009.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/21/2009] [Accepted: 09/01/2009] [Indexed: 11/29/2022] Open
Abstract
Interspecies differences can limit the translational value of excitable cells isolated from model organisms. It can be difficult to extrapolate from a drug- or mutation-induced phenotype in mice to human pathophysiology because mouse and human cardiac electrodynamics differ greatly. We present a hybrid computational-experimental technique, the cell-type transforming clamp, which is designed to overcome such differences by using a calculated compensatory current to convert the macroscopic electrical behavior of an isolated cell into that of a different cell type. We demonstrate the technique's utility by evaluating drug arrhythmogenicity in murine cardiomyocytes that are transformed to behave like human myocytes. Whereas we use the cell-type transforming clamp in this work to convert between mouse and human electrodynamics, the technique could be adapted to convert between the action potential morphologies of any two cell types of interest.
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Lee N, Authier S, Pugsley MK, Curtis MJ. The continuing evolution of torsades de pointes liability testing methods: Is there an end in sight? Toxicol Appl Pharmacol 2010; 243:146-53. [DOI: 10.1016/j.taap.2009.12.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 12/04/2009] [Accepted: 12/04/2009] [Indexed: 01/08/2023]
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