Validation and qualification of an ex vivo human cardiac tissue based assay for the assessment of the potential cardiotoxicity of pharmaceutical compounds

PROJECT SUMMARY Drug induced cardiac toxicity and adverse events remain a major challenge for both industry as well as regulators The current strategies for early identification of these potential liabilities in the drug discovery and development process involves a combination of in vitro assays animal models and an extensive ECG based cardiac repolarization study which is conducted on human subjects during Phase clinical trial These latter studies are known as Thorough QT studies TQT since they have specifically focused on drug related changes in the QT interval a biomarker for cardiac repolarization and the induction of pro arrhythmic cardiac activity While these strategies have contributed in the identification of potentially dangerous pro arrhythmic molecules it is also becoming apparent that this approach is amenable to significant improvements Recently the leadership at the Division of Cardiovascular and Renal Products of the FDA Center for Drug Evaluation and Research has facilitated a number of initiatives aimed at soliciting the development and validation of novel experimental models for assessing cardiac safety of new drugs As explicitly stated by the regulators the goal is to replace the TQT clinical studies with one or more pre clinical assays by July Dr Norman Stockbridge CSRC HESI FDA Meeting July Silver Spring MD Species differences create insurmountable limitations for all approached based on animal models In addition newer strategies relying on cardiomyocytes artificially derived from stem cells or iPS cells do not faithfully replicate all the physiological features of native adult human cardiomyocytes and do not model the effects of aging and comorbidities AnaBios has recently developed a novel ex vivo human heart based drug safety evaluation platform which is currently undergoing formal Biomarker Qualification at the FDA The technology relies upon the utilization of viable human donor hearts in the laboratory for conducting ex vivo measurements of cardiac action potentials to determine the arrhythmogenicity of new drugs This approach was initially validated in Phase I using a set of reference compounds tested in blinded fashion We demonstrated the ability of this human ex vivo assay to correctly discriminate pro arrhythmic from non pro arrhythmic drugs This new approach provides the next of kin to a human clinical cardiac study but avoids the risks related to drug exposure in humans in the clinic as well as the high costs and extended timelines which come with the clinical studies The present Phase II proposal will fully leverage our ex vivo human heart methods by further validating and refining the arrhythmogenicity model and by advancing the platform to a commercialization ready stage that will permit service of a large number of drug safety evaluations By providing researchers with the relevant human based safety data we anticipate the services resulting from this Phase II project will transform cardiac drug safety assessment PROJECT NARRATIVE The identification of cardiotoxic drugs in advance of adverse events in humans remains an area of major challenge for pharmaceutical companies and Federal regulators The present proposal aims at developing a predictive robust and cost effective laboratory methodology based on human cardiac tissue from organ donors It is expected that the technology outcome of this project will significantly improve the ability to identify potentially dangerous new drugs and therefore reduce or eliminate human exposure to such agents