Vargas Hugo M, Bass Alan S, Breidenbach Alexander, Feldman Hal S, Gintant Gary A, Harmer Alexander R, Heath Bronagh, Hoffmann Peter, Lagrutta Armando, Leishman Derek, McMahon Nick, Mittelstadt Scott, Polonchuk Liudmila, Pugsley Michael K, Salata Joseph J, Valentin Jean-Pierre
Department of Investigative Toxicology, Amgen Inc, Thousand Oaks, CA 91320, USA.
J Pharmacol Toxicol Methods. 2008 Sep-Oct;58(2):72-6. doi: 10.1016/j.vascn.2008.04.001. Epub 2008 Apr 18.
Biological therapeutic agents (biologicals), such as monoclonal antibodies (mAbs), are increasingly important in the treatment of human disease, and many types of biologicals are in clinical development. During preclinical drug development, cardiovascular safety pharmacology studies are performed to assess cardiac safety in accord with the ICH S7A and S7B regulations that guide these studies. The question arises, however, whether or not it is appropriate to apply these guidelines, which were devised primarily to standardize small molecule drug testing, to the cardiovascular evaluation of biologicals. We examined the scientific literature and formed a consensus of scientific opinion to determine if there is a rational basis for conducting an in vitro hERG assay as part of routine preclinical cardiovascular safety testing for biologicals. We conclude that mAb therapeutics have very low potential to interact with the extracellular or intracellular (pore) domains on hERG channel and, therefore, are highly unlikely to inhibit hERG channel activity based on their targeted, specific binding properties. Furthermore, mAb are large molecules (>140,000 Da) that cannot cross plasma membranes and therefore would be unable to access and block the promiscuous inner pore of the hERG channel, in contrast with typical small molecule drugs. Consequently, we recommend that it is not appropriate to conduct an in vitro hERG assay as part of a preclinical strategy for assessing the heart rate corrected QT interval (QTc) prolongation risk of mAbs and other types of biologicals. It is more appropriate to assess QTc risk by integrating cardiovascular endpoints into repeat-dose general toxicology studies performed in an appropriate non-rodent species. These recommendations should help shape future regulatory strategy and discussions for the cardiovascular safety pharmacology testing of mAbs as well as other biologicals and provide guidance for the preclinical cardiovascular evaluation of such agents.
生物治疗药物(生物制剂),如单克隆抗体(mAb),在人类疾病治疗中日益重要,并且多种类型的生物制剂正处于临床开发阶段。在临床前药物开发过程中,会根据指导这些研究的ICH S7A和S7B法规进行心血管安全药理学研究,以评估心脏安全性。然而,问题在于,将主要用于规范小分子药物测试的这些指南应用于生物制剂的心血管评估是否合适。我们查阅了科学文献并形成了科学意见共识,以确定作为生物制剂常规临床前心血管安全测试的一部分进行体外人乙醚相关基因(hERG)检测是否有合理依据。我们得出结论,单克隆抗体治疗药物与hERG通道的细胞外或细胞内(孔道)结构域相互作用的可能性非常低,因此,基于其靶向、特异性结合特性,极不可能抑制hERG通道活性。此外,与典型的小分子药物不同,单克隆抗体是大分子(>140,000道尔顿),无法穿过质膜,因此无法进入并阻断hERG通道杂乱的内部孔道。因此,我们建议,作为评估单克隆抗体和其他类型生物制剂心率校正QT间期(QTc)延长风险的临床前策略的一部分,进行体外hERG检测是不合适的。通过将心血管终点纳入在合适的非啮齿类动物中进行的重复给药一般毒理学研究来评估QTc风险更为合适。这些建议应有助于塑造未来针对单克隆抗体以及其他生物制剂心血管安全药理学测试的监管策略和讨论,并为这类药物的临床前心血管评估提供指导。