FimH-Targeting Antibody-Recruiting Molecules as Novel Drugs for Preventing Complicated Urinary Tract Infections

1摘要。尿路感染（UTI）在世界范围内极为常见，并且可导致严重的 2例并发症，包括肾瘢痕和尿脓毒症。标准治疗依赖于抗生素：经验 3种治疗单纯性UTI（uUTI）、广谱治疗复杂性UTI（cUTI）和长期预防性治疗 4例为复发性UTI（鲁蒂）。这种持续的抗生素暴露不仅会破坏肠道微生物组， 泌尿系致病性大肠埃希菌（UPEC）和肺炎克雷伯菌（Kp）的5种抗菌药物耐药性， UTI的6个主要致病因子。多重耐药尿路病原体的全球传播，例如 7例由产超广谱β-内酰胺酶（ESBL）和耐碳青霉烯类肠杆菌科引起 8（CRE），已被CDC分别指定为“严重”和“紧急”公共卫生威胁。因此，我们认为， 迫切需要9种对抗多药耐药性的新策略。其中一种方法是瞄准目标， 10抑制UPEC的关键毒力因子FimH粘附素Kp的功能。FimH是表面暴露的， 11甘露糖结合蛋白，促进细菌与宿主膀胱上皮的结合，及其功能 12对于UTI的建立和持续至关重要。使用这种抗粘附策略， 13甘露糖苷FimH拮抗剂由Fimbrion和GlaxoSmithKline开发，目前处于1b期 14项治疗uUTI的临床试验。作为这次合作的后续行动，我们开始探索下一个 15代FimH拮抗剂，通过额外招募抗体靶向更难治疗的cUTI 16从宿主免疫系统。这些被称为FimH拮抗剂抗体募集分子（FimH-ARM）的分子， 17种基于甘露糖苷的治疗剂对FimH靶点具有纳摩尔亲和力，我们的早期原型FimH-ARM具有 18在uUTI小鼠模型中显示出降低急性膀胱感染严重程度的增强能力。我们 19假设除了FimH功能的拮抗之外，FimH-ARM将提供额外的机制， 通过免疫系统的参与和延长的药代动力学（PK）， 21在cUTI中优于常规甘露糖苷的上级功效。本提案的主要目标是：（1）生成一个 22种高效的FimH-ARM先导系列，将招募天然存在的人类抗体，以对抗尿路感染 23种细菌和（2）在cUTI模型中证明体内功效。为了实现这些目标，我们将（i）扩大 24 FimH-ARM库，以鉴定具有优化的小鼠PK特征的有效先导化合物，以及（ii）测试FimH-ARM库中的 在小鼠cUTI模型中的先导FimH-ARM的体内功效和（iii）选择我们的先进先导FimH-ARM和 26建立活性谱、MoA和PK基准，用于II期中的晚期先导化合物优化。成功将 27定义为：鉴定出一种先进的电极导线FimH-ARM，其体内疗效优于其母体药物上级 28小分子FimH拮抗剂和非劣效于标准治疗抗生素，并证明了额外的 29种免疫系统MoA超过FimH拮抗作用。这些研究将促进早期临床前开发 30的一种新型的，保肾治疗，用于预防由表达FimH的尿路病原体引起的cUTI。

1 ABSTRACT. Urinary tract infections (UTI) are extremely common world-wide, and can lead to serious 2 complications, including renal scarring and urosepsis. Standard-of-care treatments rely on antibiotics: empiric 3 treatment for uncomplicated UTI (uUTI), broad-spectrum for complicated UTI (cUTI), and long-term prophylaxis 4 for recurrent UTI (rUTI). This constant antibiotic exposure not only disrupts the gut microbiome but drives 5 antimicrobial resistance among uropathogenic Escherichia coli (UPEC) and Klebsiella pneumoniae (Kp), the 6 predominant causative agents of UTI. The global spread of multidrug-resistant uropathogens, such as those 7 caused by extended spectrum b-lactamase (ESBL)-producing and carbapenem-resistant Enterobacteriaceae 8 (CRE), has been designated by the CDC as “serious” and “urgent” public health threats, respectively. Therefore, 9 new strategies to combat multidrug resistance are desperately needed. One such approach is to target and 10 inhibit the function a key virulence factor of UPEC and Kp, the FimH adhesin. FimH is a surface-exposed, 11 mannose-binding protein that facilitates bacterial binding to the host urinary bladder epithelium, and its function 12 is essential for the establishment and persistence of a UTI. Using this anti-adhesive strategy, a small molecule 13 mannoside FimH antagonist was developed by Fimbrion and GlaxoSmithKline and is currently in Phase 1b 14 clinical trials for the treatment of uUTI. As a follow-up to this collaboration, we began exploring the next 15 generation of FimH antagonists that target the more difficult-to-treat cUTI, by additionally recruiting antibodies 16 from the host immune system. Known as FimH antagonist antibody recruiting molecules (FimH-ARMs), these 17 mannoside-based therapeutics have nanomolar affinity for the FimH target and our early protype FimH-ARM has 18 shown enhanced ability to reduce the severity of acute bladder infection in a mouse model of uUTI. We 19 hypothesize that in addition to antagonism of FimH function, FimH-ARMs will provide additional mechanisms of 20 action (MoAs) through engagement of the immune system and extended pharmacokinetics (PK), resulting in 21 superior efficacy over conventional mannosides in cUTI. The main goals of this proposal are: (1) to generate a 22 highly potent lead series of FimH-ARMs that will recruit naturally occurring human antibodies to uropathogenic 23 bacteria and (2) demonstrate in vivo efficacy in a model of cUTI. To accomplish these goals, we will (i) expand 24 the FimH-ARM library to identify potent lead compounds with optimized mouse PK profiles, and (ii) test the in 25 vivo efficacy of lead FimH-ARMs in a mouse cUTI model and (iii) Select our advanced lead FimH-ARM and 26 establish the spectrum of activity, MoA, and PK benchmarks for late lead optimization in Phase II. Success will 27 be defined as: identification of an advanced lead FimH-ARM, that shows in vivo efficacy superior to its parent 28 small molecule FimH antagonist and non-inferiority to a standard-of-care antibiotic and demonstrates additional 29 immune system MoAs beyond FimH antagonism. These studies will facilitate the early preclinical development 30 of a novel, antibiotic-sparing therapeutic, for preventing cUTI caused by FimH-expressing uropathogens.