A New Toxicity Screen to Assess Mitochondrial DNA Content and Protein Synthesis

评估线粒体 DNA 含量和蛋白质合成的新毒性筛选

基本信息

批准号：
8005606
负责人：
Ross John Whittaker
金额：
$ 27.01万
依托单位：
VALA SCIENCES, INC.
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-08-15 至 2012-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8005606
关键词：
AIDS therapy Accounting Acute Adverse effects Algorithms Animals Antibiotics Antiviral Agents Biological Assay Biological Models Boxing Cardiac Cardiac Myocytes Cardiomyopathies Cardiotoxicity Cell Line Cell model Cells Clinical Trials Computer software Data Development Drug Kinetics Drug toxicity Failure Generations Health Care Costs Hepatocyte Hepatotoxicity Human Impairment In Vitro Industry Investments Long-Term Effects Measures Membrane Potentials Mitochondria Mitochondrial DNA Mitochondrial Proteins Modeling Molecular Neonatal Patients Pharmaceutical Preparations Pharmacologic Substance Phase Phase III Clinical Trials Plague Ploidies Poison Protein Biosynthesis Protein Synthesis Inhibition Rattus Reactive Oxygen Species Safety Sampling Scheme Screening procedure Signal Transduction Solutions Staging Staining method Stains Stem cells System Techniques Testing Tissues Toxic effect Toxicity Tests Toxin Ventricular Withdrawal base chemotherapeutic agent cost drug candidate drug development drug withdrawal in vitro Model induced pluripotent stem cell novel pre-clinical predictive modeling public health relevance research and development

项目摘要

DESCRIPTION (provided by applicant): Investment in research and development by pharmaceutical companies has more than tripled since the early 1990's, but the number of the new molecular entity (NME) approvals has remained stagnant. The industry is still plagued by costly late stage attrition in phase II and phase III clinical trials. Around the turn of the millennium, lack of efficacy was the main reason clinical trials were halted. However, advances in pharmacokinetics have enhanced our predictive capabilities and toxicity is now the number one reason for clinical trial failures, accounting for approximately 30-40% of withdrawals. Just as advancements in pharmacokinetics enhanced our predictive abilities and reduced clinical trial failures due to problems with efficacy, similar improvements in toxicity screening are needed to reduce the number of late stage clinical trial withdrawals. Effective predictive assays and in vitro models that are introduced early in the drug development cycle could not only aid in decreasing clinical trial withdrawals but also reduce preclinical development costs by identifying toxic candidates early on, reducing the number and cost of animal trials, and allowing a more focused effort on high quality drug candidates. Assessing mitochondrial impairment as a mechanism of toxicity represents a significant problem in toxicity screening. Traditionally, mitochondrial toxicity has been considered retrospectively; more than half of the drugs that carry black box warnings for hepato- and cardiotoxicity have been shown to act as mitochondrial toxins. While several assays exist to measure the acute effects of drugs on the mitochondria such as changes in membrane potential, mitochondrial integrity and reactive oxygen species generation, there are few assays that can assess more long term effects such as mitochondrial DNA (mtDNA) depletion and inhibition of mitochondrial protein synthesis. These two mechanisms of mitochondrial related toxicity are associated with serious and potentially fatal side effects. A number of drugs including AIDS therapies, antibiotics, and chemotherapeutic agents are associated with toxic side effects related to mtDNA depletion and inhibition of mitochondrial protein synthesis. Additionally, the FDA has mandated that all new antiviral drugs must demonstrate that they do not result in mtDNA depletion. Regardless, there are no commercially available assays that directly measure mtDNA content and/or assess mitochondrial protein synthesis. Therefore, we are proposing the development of a new assay, and an associated software solution, for use with high content screening systems, to directly measure mtDNA content and assess mitochondrial protein synthesis. The assay will then be tested in hepatocyte and cardiac model systems against compounds known to cause mtDNA depletion and protein synthesis inhibition. We also proposing the development of a predictive, in vitro, model utilizing cardiomyocytes derived from human induced pluripotent stem cells for application to safety screening during the early stages of drug development. PUBLIC HEALTH RELEVANCE: Increasing pharmaceutical R&D costs are a major contributor to the overall cost of healthcare. A large proportion of these costs are incurred due to compound attrition during preclinical and clinical trial testing. Toxicity is the primary reason for compound attrition and identifying toxic compounds early in the drug development cycle is one of the most effective ways to reduce development costs. The proposed project aims to develop an assay and a stem cell based model system to provide better predictive capabilities during early stage testing, in order to identify that demonstrate toxicities related to mitochondrial DNA depletion and protein synthesis inhibition and eliminate them early on in the development scheme.

描述（由申请人提供）：自1990年代初以来，制药公司对研发的投资已经增加了两倍多，但是新分子实体（NME）批准的数量仍然停滞不前。在第二阶段和第三阶段临床试验中，该行业仍然受到昂贵的后期流失的困扰。在千年之际，缺乏疗效是临床试验停止的主要原因。但是，药代动力学的进步增强了我们的预测能力，毒性现在是临床试验失败的第一原因，约占戒断的30-40％。正如药代动力学的进步增强了我们的预测能力和由于功效问题而导致的临床试验失败减少一样，还需要类似的毒性筛查以减少晚期临床试验提取的数量。在药物开发周期初期引入的有效预测性测定和体外模型不仅可以帮助减少临床试验提取，而且还可以通过早期识别有毒候选人来降低临床前开发成本，从而减少动物试验的数量和成本，并允许进行。更集中于高质量的候选药物。将线粒体损伤评估为毒性机制是毒性筛查中的一个重大问题。传统上，线粒体毒性被追溯考虑。超过一半的肝毒性和心脏毒性警告的药物已被证明是线粒体毒素的作用。尽管存在几种测定方法来测量药物对线粒体的急性影响，例如膜电位变化，线粒体完整性和活性氧的产生，但很少有测定方法可以评估更多的长期效应，例如线粒体DNA（MTDNA）dna和抑制作用线粒体蛋白的合成。线粒体相关毒性的这两种机制与严重且潜在的致命副作用有关。包括艾滋病疗法，抗生素和化学治疗剂在内的许多药物与与mtDNA耗竭和抑制线粒体蛋白合成有关的毒性副作用有关。此外，FDA已要求所有新的抗病毒药物必须证明它们不会导致mtDNA耗竭。无论如何，都没有直接测量mtDNA含量和/或评估线粒体蛋白合成的商业可用测定法。因此，我们提出了一种新测定和相关软件解决方案的开发，用于与高含量筛选系统一起使用，以直接测量mtDNA含量并评估线粒体蛋白质的合成。然后，该测定将在肝细胞和心脏模型系统中测试，以针对已知引起mtDNA耗竭和蛋白质合成抑制的化合物进行测试。我们还提出了利用源自人类诱导的多能干细胞的心肌细胞的预测性，体外模型的发展，以在药物开发的早期阶段应用安全筛查。公共卫生相关性：增加药物研发成本是导致医疗总成本的主要贡献者。由于临床前和临床试验测试期间的复合损耗，这些成本中的很大一部分是由于消耗而产生的。毒性是加热损耗的主要原因，并在药物开发周期初期鉴定有毒化合物是降低开发成本的最有效方法之一。拟议的项目旨在开发一种测定法和基于干细胞的模型系统，以在早期测试中提供更好的预测能力，以确定证明与线粒体DNA耗竭和蛋白质合成抑制相关的毒性，并在开发方案中早期消除它们。