Development of multispecific antibodies for the treatment of Pseudomonas aeruginosa infection

摘要 铜绿假单胞菌是一种主要病原体，可导致广泛的医院和社区- 获得性感染。治疗这些感染的最大障碍是抗生素耐药性；不断上升的疫情-- 多重耐药铜绿假单胞菌是一个主要的公共卫生问题。因此，有一个紧急的 需要开发新的治疗方法，以绕过细菌应用的耐药机制。 Inhibrx开发了一个基于单域抗体(SdAb)的平台，以支持开发新的 抗生素根据不同的作用机制来规避耐药性的发展。这个平台 是一种模块化形式，其中多个仅骆驼重链抗体结合域首尾相连， 与效应域(Fc)一起，创建针对多个 表位。我们建议开发一种针对铜绿假单胞菌的治疗性抗体，同时针对多个靶点。 在一个还含有功能性人IgG1的分子中，分泌出三重毒素和细胞表面靶标 FC域。Inhibrx使用其多功能抗体形式开发出两种六价铅，三特异性，人类- 针对T3SS毒力机制关键成分的两个表位具有特异性的分子 并对抗在所有铜绿假单胞菌菌株中高度保守的外膜脂蛋白。这些防腐剂- IES与所有测试的假单胞菌菌株结合，并在小鼠感染模型中显示出更好的疗效 成为目前潜在的抗假单胞菌抗体疗法的领先者。 我们假设，基于这些抗体的治疗方法将被证明优于所有其他现有的绿脓杆菌- 吉诺萨疗法。毒素阻断功能有望保护招募到in-in部位的免疫细胞。 感染，而细胞结合‎的能力将使细菌的调理，随后他们的吞噬和 由免疫系统清除。‎在这个项目中，我们寻求通过调查来获得我们的候选抗体- 国家新药(IND)使毒理学成为可能。在阶段I(特定目标#1)中，我们建议将这些反- 体外结合铜绿假单胞菌和阻断T3SS依赖细胞毒的能力及比较 它们在体内感染模型中的有效性，确立了其中一种作为临床候选药物。这个PRO的第二阶段- OJECT将专注于进行IND启用研究，以促进采用在阶段选择的候选抗体 I到临床试验。首先将在人类FcRN转基因小鼠身上进行特定目标#2的药代动力学(PK)测试， 因为人类抗体在野生型啮齿动物中的半衰期通常相对较短。IND-启用多剂量毒素- 然后将在非人类灵长类动物(NHP)中进行iCity研究，以确定我们临床上的安全性和PK 候选人。在这个项目结束时，Inhibrx将开发出一种亟需的抗体疗法 用于治疗将准备用于IND备案的耐多药假单胞菌。我们希望这次治疗会有很好的效果- 对耐多药铜绿假单胞菌感染具有平和和变革性。

Abstract Pseudomonas aeruginosa is a major pathogen that causes a wide range of hospital- and community- acquired infections. The greatest obstacle to treating these infections is antibiotic resistance; the rising preva- lence of multidrug-resistant (MDR) P. aeruginosa is a major public health concern. Thus, there is an urgent need to develop novel therapeutics, which can circumvent drug resistance mechanisms applied by bacteria. Inhibrx has developed a platform based on single domain antibodies (sdAb) to enable development of novel antibiotics based on different mechanisms of action to circumvent the development of resistance. This platform is a modular format wherein multiple camelid heavy chain only antibody binding domains are joined end to end, together with an effector domain (Fc), to create multi-specific, multivalent antibodies targeting multiple epitopes. We propose to develop a therapeutic antibody against P. aeruginosa that simultaneously targets mul- tiple secreted toxins as well as a cell-surface target, in a molecule that also contains a functional human IgG1 Fc domain. Inhibrx has used its versatile antibody format to develop two lead hexavalent, tri-specific, human- ized molecules with specificity against two epitopes of a crucial component of the T3SS virulence mechanism and against an outer membrane lipoprotein that is highly conserved in all P. aeruginosa strains. These antibod- ies bind to all Pseudomonas strains tested and show improved efficacy in a murine infection model compared to the current leader in potential anti-Pseudomonas antibody therapeutics. We hypothesize that a therapeutic based on these antibodies will prove superior to all other existing P. aeru- ginosa therapeutics. Toxin blocking functionality is expected to protect immune cells recruited to the site of in- fection, while cell binding ‎capability will enable opsonization of the bacteria, followed by their phagocytosis and clearance by the immune system. ‎In this project we seek to take our candidate antibodies through Investiga- tional New Drug (IND) enabling toxicology. In Phase I (Specific Aim #1) we propose to characterize these anti- bodies for their ability to bind P. aeruginosa and block T3SS dependent cytotoxicity in vitro and to compare their efficacy in in vivo models of infection, establishing one of them as a clinical candidate. Phase II of this pro- ject will focus on performing IND enabling research to facilitate taking the candidate antibody selected in Phase I to clinical trials. Pharmacokinetics (PK) will first be tested in Specific Aim #2 in human FcRn transgenic mice, as human antibodies generally have relatively short half-lives in wildtype rodents. IND-enabling multi-dose tox- icity studies will then be performed in non-human primates (NHPs) to determine safety and PK of our clinical candidate. At the conclusion of this project, Inhibrx will have developed a much needed antibody therapeutic for treating MDR Pseudomonas that will be ready for IND filing. We expect this therapeutic to be highly im- pactful and transformative for MDR P. aeruginosa infections.