Takahashi Ryan H, Khojasteh Cyrus, Wright Matthew, Hop Cornelis E C A, Ma Shuguang
Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Drug Metab Lett. 2017 Nov 17;11(1):21-28. doi: 10.2174/1872312811666170710193229.
The regulatory guidances on metabolites in safety testing (MIST) by US Food and Drug Administration (FDA) and International Conference on Harmonisation (ICH) describe the necessity to assess exposures of major circulating metabolites in humans at steady state relative to exposures achieved in nonclinical safety studies prior to the initiation of large scale clinical trials. This comparison can be accomplished by measuring metabolite concentrations in animals and humans with validated bioanalytical methods. However, bioanalysis of metabolites in multiple species and multiple studies is resource intensive and may impact the timelines of clinical studies.
A simple, reliable and accurate method has been developed for quantitative assessment of metabolite coverage in preclinical safety species by mixing equal volume of human plasma with blank plasma of animal species and vice versa followed by an analysis using LC-SRM or LC-HRMS. Here, we explored the reliability and accuracy of this method in several development projects at Genentech and compared the results to those obtained from validated bioanalytical methods.
The mixed-matrix method provided comparable accuracy (within ±20%) to those obtained from validated bioanalysis but does not require authentic standards or radiolabeled compounds, which could translate to time and resource savings in drug development.
Quantitative assessment of metabolite coverage in safety species can be made using mixed matrix method with similar accuracy and scientific rigor to those obtained from validated bioanalytical methods. Moving forward, we are encouraging the industry and regulators to consider accepting the mixed matrix method for assessing metabolite exposure comparisons between humans and animal species used in toxicology studies.
美国食品药品监督管理局（FDA）和国际协调会议（ICH）关于安全性试验中代谢物（MIST）的监管指南描述了在大规模临床试验开始前，有必要评估人体稳态下主要循环代谢物的暴露量，并与非临床安全性研究中所达到的暴露量进行比较。这种比较可以通过使用经过验证的生物分析方法测量动物和人体中的代谢物浓度来完成。然而，对多个物种和多项研究中的代谢物进行生物分析需要大量资源，并且可能会影响临床研究的时间表。
已开发出一种简单、可靠且准确的方法，通过将等量的人血浆与动物物种的空白血浆混合，反之亦然，然后使用液相色谱-选择性反应监测（LC-SRM）或液相色谱-高分辨质谱（LC-HRMS）进行分析，来定量评估临床前安全性物种中的代谢物覆盖情况。在此，我们在基因泰克的几个开发项目中探索了该方法的可靠性和准确性，并将结果与从经过验证的生物分析方法获得的结果进行比较。
混合基质法提供了与经过验证的生物分析相当的准确度（±20%以内），但不需要真实标准品或放射性标记化合物，这可以在药物开发中节省时间和资源。
可以使用混合基质法对安全性物种中的代谢物覆盖情况进行定量评估，其准确度和科学严谨性与经过验证的生物分析方法相当。展望未来，我们鼓励行业和监管机构考虑接受混合基质法，用于评估毒理学研究中使用的人类和动物物种之间的代谢物暴露比较。
