Host Directed Orynotide for MDR Gram Negative Bacterial Infections

项目摘要 这项拨款提案的目标是推进一种新型大环肽的临床前开发， Orynotide™ MTD 12813，用于治疗多重耐药（MDR）革兰氏阴性细菌感染， 最初的重点是由碳青霉烯耐药肠杆菌科（CRE）引起的感染。的出现 多种CRE病原体的感染已经造成了紧急的公共卫生威胁，因为碳青霉烯类是 作为治疗由MDR细菌病原体比例增加引起的感染的最后药物。只有两个物种， 肺炎克雷伯氏菌和大肠埃希氏菌每年在美国引起估计140，000例医院感染。 仅在美国，许多人对碳青霉烯耐药。全球一致认为，新的预防性和 迫切需要治疗策略来对抗日益严重的MDR细菌感染问题。的 申请人，θ-防御素生物学领域的领导者，正在通过开发Orynotides， 一类新的宿主导向的抗微生物大环肽生物启发的结构和生物 θ-防御素的性质，大环肽仅在旧大陆猴中表达（但不是 人类）。利用θ-防御素的多效性宿主防御特性，我们产生了一个新的 Orynotides，包括几种在MDR革兰氏阴性败血症模型中高度有效的化合物。 点击到铅研究确定MTD 12813作为临床前开发的主要候选药物，作为第一个 用于MDR革兰氏阴性感染类免疫抑制剂。在小鼠腹膜脓毒症模型中， MTD 12813的单剂量给药是高度有效的（伴随细菌的存活率提高 清除率）。pneumoniae和CRE-E。大肠杆菌，另外还显示， 对耐多药鲍曼不动杆菌引起的败血症有效。与病原体的范围一致 MTD 12813在体内对其有活性，我们表明肽的作用模式是免疫性的， 促进宿主介导的细菌清除，刺激吞噬作用和中性粒细胞募集， 调节否则失调的促炎细胞因子的水平。这些数据表明MTD 12813是 一种有效治疗革兰氏阴性细菌病原体的新型免疫抑制剂。所述肽 易于生产（约1.5 g），在人血浆和全血中高度稳定，对细菌具有抗性 蛋白酶，并且当通过多种途径施用时耐受良好。在拟议的研究中，我们将推进 MTD 12813的临床前表征。目标1研究将包括GLP MTD 12813和其他 关键试剂、药代动力学（PK）和PK/药效学分析以及ADME研究。目标2将重点 阐明细胞和分子水平的作用机制。Aim 3目标包括临床前 大鼠和比格犬的非GLP安全性和毒代动力学研究，免疫原性评价，开发 抗药抗体测定，并最终进行正式的GLP安全性研究。这些目标的目的是 将MTD 12813的临床前开发推进到向FDA提交IND申请。

PROJECT SUMMARY The goal of this grant proposal is to advance the preclinical development of a novel macrocyclic peptide, Orynotide™ MTD12813, for treatment of multidrug resistant (MDR) Gram negative bacterial infections, with the initial focus being on infections caused by carbapenem-resistant Enterobacteriaceae (CRE). The emergence of infections by multiple CRE pathogens has created an urgent public health threat, because carbapenems are drugs of last resort for infections caused by an increasing fraction of MDR bacterial pathogens. Just two species, Klebsiella pneumoniae and Escherichia coli, cause an estimated 140,000 nosocomial infections per year in the United States alone, and many are carbapenem resistant. There is global consensus that new preventive and therapeutic strategies are urgently needed to combat the growing problem of MDR bacterial infections. The applicants, leaders in the field of θ-defensin biology, are responding to this need by developing Orynotides, a new class of host-directed antimicrobial macrocyclic peptides bioinspired by the structural and biological properties of theta (θ)-defensins, macrocyclic peptides expressed exclusively in Old World monkeys (but not humans). Exploiting the pleiotropic host defense properties of θ-defensins, we produced a library of novel Orynotides that includes several compounds that are highly effective in MDR Gram negative septicemia models. Hit-to-lead studies identified MTD12813 as the lead Orynotide candidate for preclinical development as a first- in-class immunotherapeutic agent for MDR Gram negative infections. In the mouse peritoneal sepsis model, single dose administration of MTD12813 is highly effective (enhanced survival with concomitant bacterial clearance) against multiple strains of CRE-K. pneumoniae and CRE-E. coli, and additionally was shown to be effective in septicemia caused by MDR Acinetobacter baumannii. Consistent with the range of pathogens against which MTD12813 is active in vivo, we showed that the peptide’s mode of action is immunotherapeutic, promoting host-mediated bacterial clearance, stimulating phagocytosis and neutrophil recruitment, while modulating levels of otherwise dysregulated proinflammatory cytokines. These data indicate that MTD12813 is a novel immunotherapeutic agent effective in the treatment of Gram negative bacterial pathogens. The peptide is readily manufacturable ( ~1.5 g on hand), highly stable in human plasma and whole blood, resistant to bacterial proteases, and well tolerated when administered by numerous routes. In the proposed studies, we will advance the preclinical characterization of MTD12813. Aim 1 studies will include production of GLP MTD12813 and other critical reagents, pharmacokinetic (PK) and PK/pharmacodynamic analyses, and ADME studies. Aim 2 will focus on illuminating mechanism(s) of action at the cellular and molecular level. Aim 3 objectives will include preclinical non-GLP safety and toxicokinetic studies in rats and beagle dogs, evaluation of immunogenicity, development of an antidrug antibody assay, and culminate with formal GLP safety studies. The goal of these aims is to advance the preclinical development of MTD12813 to IND filing with the FDA.