8 results on '"Gintant G"'
Search Results
2. Drug-induced cardiac abnormalities in premature infants and neonates.
- Author
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Pesco-Koplowitz L, Gintant G, Ward R, Heon D, Saulnier M, and Heilbraun J
- Subjects
- Animals, Humans, Infant, Infant, Newborn, Drug-Related Side Effects and Adverse Reactions complications, Heart Defects, Congenital chemically induced, Infant, Premature
- Abstract
The Cardiac Safety Research Consortium (CSRC) is a transparent, public-private partnership that was established in 2005 as a Critical Path Program and formalized in 2006 under a Memorandum of Understanding between the United States Food and Drug Administration and Duke University. Our continuing goal is to advance paradigms for more efficient regulatory science related to the cardiovascular safety of new therapeutics, both in the United States and globally, particularly where such safety questions add burden to innovative research and development. This White Paper provides a summary of discussions by a cardiovascular committee cosponsored by the CSRC and the US Food and Drug Administration (FDA) that initially met in December 2014, and periodically convened at FDA's White Oak headquarters from March 2015 to September 2016. The committee focused on the lack of information concerning the cardiac effects of medications in the premature infant and neonate population compared with that of the older pediatric and adult populations. Key objectives of this paper are as follows: Provide an overview of human developmental cardiac electrophysiology, as well as the electrophysiology of premature infants and neonates; summarize all published juvenile animal models relevant to drug-induced cardiac toxicity; provide a consolidated source for all reported drug-induced cardiac toxicities by therapeutic area as a resource for neonatologists; present drugs that have a known cardiac effect in an adult population, but no reported toxicity in the premature infant and neonate populations; and summarize what is not currently known about drug-induced cardiac toxicity in premature infants and neonates, and what could be done to address this lack of knowledge. This paper presents the views of the authors and should not be construed to represent the views or policies of the FDA or Health Canada., (Copyright © 2017. Published by Elsevier Inc.)
- Published
- 2018
- Full Text
- View/download PDF
3. A New Perspective in the Field of Cardiac Safety Testing through the Comprehensive In Vitro Proarrhythmia Assay Paradigm.
- Author
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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, and Vandenberg JI
- Subjects
- Animals, Humans, Long QT Syndrome chemically induced, Long QT Syndrome diagnosis, Torsades de Pointes chemically induced, Torsades de Pointes diagnosis, Arrhythmias, Cardiac chemically induced, Arrhythmias, Cardiac diagnosis, Drug-Related Side Effects and Adverse Reactions diagnosis, Drug-Related Side Effects and Adverse Reactions etiology, Heart drug effects
- 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., (© 2015 Society for Laboratory Automation and Screening.)
- Published
- 2016
- Full Text
- View/download PDF
4. Integrated and translational nonclinical in vivo cardiovascular risk assessment: gaps and opportunities.
- Author
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Berridge BR, Hoffmann P, Turk JR, Sellke F, Gintant G, Hirkaler G, Dreher K, Schultze AE, Walker D, Edmunds N, Halpern W, Falls J, Sanders M, and Pettit SD
- Subjects
- Animals, Disease Models, Animal, Drug Industry methods, Endpoint Determination, Humans, MicroRNAs metabolism, Research Design, Risk Assessment methods, Species Specificity, Cardiovascular Diseases chemically induced, Drug Design, Drug-Related Side Effects and Adverse Reactions
- Abstract
Cardiovascular (CV) safety concerns are a significant source of drug development attrition in the pharmaceutical industry today. Though current nonclinical testing paradigms have largely prevented catastrophic CV events in Phase I studies, many challenges relating to the inability of current nonclinical safety testing strategies to model patient outcomes persist. Contemporary approaches include a spectrum of evaluations of CV structure and function in a variety of laboratory animal species. These approaches might be improved with a more holistic integration of these evaluations in repeat-dose studies, addition of novel endpoints with greater sensitivity and translational application, and use of more relevant animal models. Particular opportunities present with advances in imaging capabilities applicable to rodent and non-rodent species, technical capabilities for measuring CV function in repeat-dose animal studies, detection and quantitation of microRNAs and wider use of alternative animal models. Strategic application of these novel opportunities considering putative CV risk associated with the molecular drug target as well as inherent risks present in the target patient population could tailor or 'personalize' nonclinical safety assessment as a more translational evaluation. This paper is a call to action for the clinical and nonclinical drug safety communities to assess these opportunities to determine their utility in filling potential gaps in our current cardiovascular safety testing paradigms., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
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5. Ions, equations and electrons: the evolving role of computer simulations in cardiac electrophysiology safety evaluations.
- Author
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Gintant G
- Subjects
- Algorithms, Computer Simulation, Drug Evaluation, Preclinical, Electrons, Electrophysiologic Techniques, Cardiac, Humans, Ions, Drug-Related Side Effects and Adverse Reactions, Heart drug effects, Models, Cardiovascular
- Abstract
Reliable preclinical cardiac safety evaluations of drug candidates are essential for selecting the best therapeutic agents. Advanced automated patch clamp technologies now allow for characterizing drug effects on multiple cardiac currents, enabling subsequent simulations of integrated electrophysiological responses on cellular, tissue and organ levels. In this issue, Mirams et al. summarize the strengths and limitations of models and simulations predicting drug-induced electrophysiological responses, emphasizing delayed repolarization and Torsades de Pointes pro-arrhythmia. The utility of computational approaches is contingent upon realistic models of ventricular electrophysiology, robust characterization of drug-channel interactions and an understanding of channel-myocyte interactions and pro-arrhythmic mechanisms. Simulations evaluating effects on repolarization (hazard identification) should aid in selecting safer drug candidates early in drug discovery, while simulations evaluating risk of Torsades de Pointes (incorporating known risk factors) should quantify pro-arrhythmic risk and reduce the need for costly clinical QT studies later in development. The wider adoption of realistic models and simulation studies will depend on simulation performance compared with 'gold standard' clinical findings., (© 2012 Abbott Laboratories. British Journal of Pharmacology © 2012 The British Pharmacological Society.)
- Published
- 2012
- Full Text
- View/download PDF
6. How do the top 12 pharmaceutical companies operate safety pharmacology?
- Author
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Ewart L, Gallacher DJ, Gintant G, Guillon JM, Leishman D, Levesque P, McMahon N, Mylecraine L, Sanders M, Suter W, Wallis R, and Valentin JP
- Subjects
- Data Collection, Drug Design, Drug Evaluation, Preclinical economics, Drug Industry economics, Drug Industry organization & administration, Income statistics & numerical data, Outsourced Services, Pharmaceutical Preparations economics, Pharmacokinetics, Pharmacology economics, Pharmacology organization & administration, Toxicity Tests, Drug Evaluation, Preclinical methods, Drug Industry methods, Drug-Related Side Effects and Adverse Reactions, Pharmacology methods
- Abstract
Introduction: How does safety pharmacology operate in large pharmaceutical companies today? By understanding our current position, can we prepare safety pharmacology to successfully navigate the complex process of drug discovery and development?, Methods: A short anonymous survey was conducted, by invitation, to safety pharmacology representatives of the top 12 pharmaceutical companies, as defined by 2009 revenue figures. A series of multiple choice questions was designed to explore group size, accountabilities, roles and responsibilities of group members, outsourcing policy and publication record., Results: A 92% response rate was obtained. Six out of 11 companies have 10 to 30 full time equivalents in safety pharmacology, who hold similar roles and responsibilities; although the majority of members are not qualified at PhD level or equivalent. Accountabilities were similar across companies and all groups have accountability for core battery in vivo studies and problem solving activities but differences do exist for example with in vitro safety screening and pharmacodynamic/pharmokinetic modeling (PK/PD). The majority of companies outsource less than 25% of studies, with in vitro profiling being the most commonly outsourced activity. Finally, safety pharmacology groups are publishing 1 to 4 articles each year., Conclusion: This short survey has highlighted areas of similarity and differences in the way large pharmaceutical companies operate safety pharmacology., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
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7. An evaluation of hERG current assay performance: Translating preclinical safety studies to clinical QT prolongation.
- Author
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Gintant G
- Subjects
- Animals, Clinical Trials as Topic, Cricetinae, Drug Evaluation, Preclinical, Drug Labeling, Heart, Humans, Long QT Syndrome metabolism, Risk, Drug-Related Side Effects and Adverse Reactions, Ether-A-Go-Go Potassium Channels metabolism, Long QT Syndrome chemically induced
- Abstract
Block of delayed rectifier current (I(Kr), Kv11.1 encoding the hERG gene) is associated with delayed cardiac repolarization (QTc prolongation), a surrogate marker of proarrhythmia. Despite its recognized role in assessing QTc prolongation risk, a quantitative analysis of the utility and limitations of the hERG current assay has not been reported. To benchmark hERG assay performance, this retrospective study compared hERG block potency with drug-induced QTc prolongation assessed during rigorous thorough QT (TQT) clinical studies for 39 drugs from multiple classes. To place block in context, hERG safety margins (IC(50) values for block/mean maximal plasma drug concentrations during TQT studies) were compared to QTc prolongation (QTc increase≥5ms). Most (9/10) drugs eliciting essentially no hERG block at maximal concentrations demonstrate no QTc prolongation despite representing a wide hERG safety margin range. Based on receiver-operator characteristics, a hERG safety margin of 45 provided optimal overall performance linking safety margins to QTc prolongation (sensitivity (true positive rate)=0.64, specificity (true negative rate)=0.88); the area under the receiver-operator curve (0.72) is indicative of moderate overall concordance. Likelihood ratios calculated from multitier contingency tables suggest that QTc prolonging drugs are only 5-7 times as likely to demonstrate low safety margins (1-30 range) compared to drugs that do not prolong QTc. Paradoxically, higher safety margins demonstrate lesser confidence predicting prolongation. The overall limitations of hERG safety margins shown using these quantitative, evidence-based approaches highlight the need for additional preclinical assays and adaptive strategies throughout drug discovery to reliably mitigate QTc prolongation risk., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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8. ILSI-HESI cardiovascular safety subcommittee initiative: evaluation of three non-clinical models of QT prolongation.
- Author
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Hanson LA, Bass AS, Gintant G, Mittelstadt S, Rampe D, and Thomas K
- Subjects
- Action Potentials drug effects, Animals, Chemistry, Pharmaceutical, Data Interpretation, Statistical, Disease Models, Animal, Dogs, Dose-Response Relationship, Drug, ERG1 Potassium Channel, Electric Stimulation, Electrocardiography drug effects, Electrophysiology, Ether-A-Go-Go Potassium Channels drug effects, Ether-A-Go-Go Potassium Channels metabolism, Nerve Fibers physiology, Patch-Clamp Techniques, Pharmacokinetics, Purkinje Fibers drug effects, Purkinje Fibers physiology, Telemetry, Torsades de Pointes chemically induced, Torsades de Pointes physiopathology, Drug-Related Side Effects and Adverse Reactions, Long QT Syndrome chemically induced, Long QT Syndrome physiopathology
- Abstract
Introduction: Drugs that delay cardiac repolarization pose potential safety risks to patients and cause serious regulatory concern because of the link between QT interval prolongation and the potentially fatal arrhythmia torsades de pointes (TdP). Predicting which drugs will cause TdP is an inexact and difficult science. The utility of non-clinical assays was not well understood due in part to variability in methods, species, and consistency in the assays reported in the literature. The Health and Environmental Sciences Institute of the International Life Sciences Institute (ILSI/HESI) outlined a set of studies to determine how well selected commonly used non-clinical assays identified compounds known to cause TdP and prolong QT interval in humans., Methods: Compounds known to prolong ventricular repolarization and compounds considered safe by years of clinical use were tested in three assays: HERG ionic current, Purkinje fiber repolarization, and in vivo QT studies in conscious telemeterized dogs., Results: The data from each of these assays demonstrate that compounds that may pose a proarrhythmia risk for patients can be distinguished from those that are considered safe., Discussion: Taken collectively, the in-vitro and in-vivo preclinical results can be integrated to develop an accurate preclinical risk assessment to support clinical safety.
- Published
- 2006
- Full Text
- View/download PDF
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