A novel, multiparametric cardiac safety assay using human myocytes

描述（由申请人提供）：近年来，与使用非心脏药物相关的不良心脏事件（包括心源性猝死）的报道越来越多，这是一个主要的公共卫生问题。事实上，在过去的15年中，有6种非心脏药物因与获得性长QT综合征（acLQTS）有关而不得不退出市场，这种综合征的特征是点扭转心律失常和心源性猝死。由于acLQTS对患者护理以及未来治疗性化合物的发展具有巨大的影响，因此及早认识到治疗性化合物的心脏负荷是很重要的。为了减少acLQTS的发生率，监管机构与制药行业合作制定了指南，评估新的测试化合物延缓心脏复极的潜力。不幸的是，大多数已经建立的安全性测试并不能可靠地识别与动作电位延长无关的机制（如异常脉冲传导、复极化动力学或钙调节失调）产生心律失常的化合物。此外，大多数安全性试验是在异源表达系统或非人类心肌细胞中进行的，这可能进一步限制了它们对人类风险的预测价值，因为心脏复极的物种间差异。因此，许多心脏毒性化合物可能在传统的安全筛选中未被检测到，但在药物开发的后期阶段甚至在批准用于人类使用后显示出心律失常。鉴于大多数临床前安全性分析的重大缺陷，本提案旨在开发和验证一种新的集成分析平台，以高特异性和敏感性检测全面的心律失常原底物。我们的检测平台利用来自诱导多能干细胞的人类心肌细胞和多种生理相关参数的荧光记录，包括动作电位持续时间、钙瞬态和传导速度，以检测心律失常事件的风险增加。该提案的具体目标是：1。用一组表征良好的测试化合物验证我们的新型分析平台。2. 目的：建立一种具有高预测价值的多参数心律失常风险评估算法。本提案中描述的综合分析平台有可能取代目前在先导物发现和先导物开发之间使用的整个临床前安全性分析系统，因为没有其他临床前安全性分析方法如此全面。

DESCRIPTION (provided by applicant): A major public health concern in recent years has been increasing reports of adverse cardiac events, including sudden cardiac death, that have been associated with use of non-cardiac drugs. In fact, in the last 15 years six non-cardiac drugs had to be withdrawn from the market after being linked to acquired long QT syndrome (acLQTS) which is characterized by torsades de pointes arrhythmias and sudden cardiac death. Since acLQTS has enormous consequences for patient care as well as for the development of future therapeutic compounds, it is important that the cardiac liability of therapeutic compounds be recognized early on. To reduce the incidence of acLQTS, regulatory agencies in collaboration with pharmaceutical industry have instituted guidelines that assess the potential of novel test compounds to delay cardiac repolarization. Unfortunately, most safety tests that have been instituted do not reliably identify compounds that produce arrhythmias by mechanisms unrelated to action potential prolongation such as abnormal impulse conduction, repolarization dynamics or calcium dysregulation. In addition, most safety tests are performed either in heterologous expression systems or non-human cardiomyocytes which may further limit their predictive value for human risk due to interspecies variation in cardiac repolarization. Thus, many cardiotoxic compounds may go undetected in conventional safety screens yet demonstrate proarrhythmia during later stages of drug development or even after approval for human use. Given the significant shortcomings of most preclinical safety assays the present proposal has been designed to develop and validate a novel, integrated assay platform that detects a comprehensive range of proarrhythmia substrates with high specificity and sensitivity. Our assay platform utilizes human cardiomyocytes derived from induced pluripotent stem cells and fluorescent- based recordings of multiple physiological relevant parameters including action potential duration, calcium transients and conduction velocity to detect an increased risk for proarrhythmic events. The specific aims of the proposal are: 1. to validate our novel assay platform with a panel of well characterized test compounds. 2. To develop a novel multiparametric algorithm to assess proarrhythmic risk with high predictive value. The integrated assay platform described in the present proposal has the potential to supplant a whole battery of preclinical safety assays currently used at the interface between lead discovery and lead development as no other preclinical safety assay is as comprehensive.