Development of WecA-targeting immune potentiators to treat carbapenem-resistant Enterobacteriaceae (CRE) infections

开发 WecA 靶向免疫增强剂来治疗碳青霉烯类耐药肠杆菌 (CRE) 感染

• 批准号: 10415522
• 负责人: Terry Roemer
• 金额: $ 100万
• 依托单位: PROKARYOTICS, INC.
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10415522
• 关键词: Address; Anabolism; Antibiotics; Bacteremia; Bacteria; Bacterial Infections; Bacterial Pneumonia; Binding; Cancerous; Carbapenems; Cell Survival; Cells; Centers for Disease Control and Prevention (U.S.); Chemicals; Clinical; Colistin; Communities; Complement; Data; Development; Dose; Enterobacter; Enterobacteriaceae; Enterobacteriaceae Infections; Epidemic; Escherichia coli; Essential Genes; Exposure to; Formulation; Fosfomycin; Genes; Genetic; Goals; Gram-Negative Bacteria; Growth; HepG2; Hospitals; Imipenem; Immune; Immune Targeting; Immune system; Immunooncology; In Vitro; Infection; Innate Immune System; Ion Channel; Klebsiella pneumoniae; Lead; Libraries; Life; Maps; Mediating; Meropenem; Modeling; Multi-Drug Resistance; Mutation; New Agents; O Antigens; Oral; Organism; Orthologous Gene; Pathogenesis; Pathway interactions; Pattern; Permeability; Pharmaceutical Preparations; Pharmacology; Phase; Plasmids; Polymyxins; Production; Property; Pseudomonas aeruginosa; Rattus; Reporter; Reporting; Resistance; Risk; Rodent; Rodent Model; Route; Safety; Septicemia; Serum; Siderophores; Source; Superbug; Taro Vegetable; Testing; analog; antimicrobial; bactericide; base; beta-Lactam Resistance; beta-Lactamase; beta-Lactams; carbapenem resistance; carbapenem-resistant Enterobacteriaceae; commensal bacteria; doripenem; drug repurposing; extracellular; gene product; gut microbiota; in vivo; inhibitor/antagonist; innovation; member; mortality; mutant; new therapeutic target; novel; novel therapeutics; overexpression; pathogen; periplasm; programmed cell death protein 1; public health relevance; resistance mechanism; scale up; screening; success; tigecycline

Abstract In 2013, the CDC designated carbapenem-resistant Enterobacteriaceae (CRE) an Urgent Threat, and in 2017, the WHO designated it a Priority 1 “critical superbug”. As few therapies remain to treat CRE, the risk of “pan- resistant” CRE, untreatable by any currently available antibiotic, increases. Entirely new agents with novel mechanisms of action (MOA) not cross-resistant to SOC agents languish. Our proposal aims to develop an O- antigen (O-a) biosynthetic inhibitory agent that potentiates serum-mediated killing (SMK) and is efficacious in a CRE rodent model of infection. We have shown that the O-a biosynthesis gene wecA, a nonessential gene under standard growth conditions, is essential for growth and pathogenesis in the presence of mammalian serum. Our proposal outlines a plan to develop synthetic inhibitors of WecA that we previously discovered and optimized to inhibit the Gram-positive WecA ortholog, TarO. Our Aims are: Aim 1 (Phase 1; Ph1). Screening, MOA studies, and Proof-of-Concept in vivo Studies. (1) Complete lux reporter screening of the tarocin focused library for SMK against WT and ΔtolC E. coli (Ec), (2) directly confirm tarocins inhibit EcWecA as their MOA for eliciting SMK, (3) demonstrate that tarocin-induced SMK extends to Kp, and (4) demonstrate proof-of-concept in vivo efficacy. Milestone 1. Screen ~600 additional tarocin analogs for SMK activity and identify up to 4 chemically distinct tarocin subseries demonstrating i) > 4-fold EC50 shift in SMK by EcWecA overexpression, ii) dose-dependent depletion of O-a in a whole-cell context, iii) causal drugR mutations mapping to EcwecA, iv) SMK activity against Kp DtolC, v) >90% HepG2 cell viability at 25X MIC, and vi) favorable 50% protective dose for survival in a rat septicemia model using an efflux-deficient Ec strain. Aim 2 (Ph2). Lead ID/Opt. Identify tarocins with potent WT Ec and Kp SMK by (1) empirically testing analogs for SMK against panel of Ec/Kp permeability/efflux deficient mutants, (2) employing recent physicochemical rules of GN entry, and (3) exploring siderophore conjugation to drive SAR efforts. We will also optimize PK and drug- like properties. Milestone 2. Identify up to 3 analogs demonstrating i) Ec/Kp WT activity (MIC in serum [MICs] <1 ug/ml), ii) PK exposure to cover MICs for 4 hrs, iii) Ec/Kp target/pathway engagement selectivity including tarocinR wecA mutation in Kp, v) Ec/Kp FOR <1x10-9 at 8X MICs, vi) MICs90 <2 ug/ml (100 isolates), and vii) > 90% HepG2/HEK293 viability at 50X MICs, clean vs CYP/ion channels (>10 uM), and PanLabs IC50 >10 uM. Aim 3 (Ph2). In vivo efficacy demonstration. (1) Optimize synthetic routes to efficiently prepare 3 analogs for formulation and dose-ranging rat PK studies, (2) identify formulation vehicles for the 3 analogs to enable oral and IV PK dosing in in vivo studies, and (3) demonstrate in vivo efficacy for our top compound in a rodent septicemia model using Ec and Kp strains. Milestone 3. Synthesize 500 mg (>95% purity) of up to 3 optimal analogs that best satisfy Aim 2 milestones, identify formulation in a safety approved vehicle that achieves 10X MICS90 target exposure, and demonstrate > 3 log reduction of Ec and Kp bacterial burden after 24h treatment.

摘要