Optimization of Neoglycoside Antibiotics for Nosocomial Pathogens and Select Agen

描述（申请人提供）：革兰氏阴性菌多重耐药是ICU环境中感染患者的常见问题。对于铜绿假单胞菌和不动杆菌来说，没有抗生素对生物体起作用并不罕见，这基本上使我们回到了前抗生素时代。在选定药物中也定义了耐药性，例如马达加斯加鼠疫耶尔森菌的氨基糖苷耐药性。Achaogen已经开发了几个系列的新型氨基糖苷类抗生素（neglycosides）。这些药物对多种多重耐药革兰氏阴性杆菌和耐甲氧西林金黄色葡萄球菌（MRSA）的活性显著提高。在不同的系列中，先导化合物已被鉴定出对铜绿假单胞菌和不动杆菌具有强效活性。本提案的目的是在提案的范围内检查最多5个这些分子，对它们进行排序，并对至少两个分子进行新药应用。氨基糖苷的使用越来越少，因为它们的耐药性越来越强，而且有可能引起肾毒性。这些新糖苷消除了许多与耐药性有关的问题。在Specific Aim #1中，我们将使用我们的中空纤维感染模型来研究候选分子。我们可以确定暴露目标，这将导致最佳的细菌细胞杀死和耐药细菌亚群的抑制。这些目标将通过应用创新的大型数学混合模型来确定。在具体目标# 2中，我们将采用两种动物模型来验证这些暴露目标。由于小鼠和人类的半衰期不同，我们将采用一种新颖的方法，在所有动物模型中“人性化”给药。这些包括革兰氏阴性肺炎的小鼠模型和小鼠大腿感染作为皮肤/皮肤结构感染的替代品。后一种模型将在中性粒细胞减少和正常条件下运行。我们将应用另一种全新的模型来理解粒细胞对病原体的杀伤作用。我们将在了解粒细胞影响的情况下验证SA #1的暴露目标。在Specific Aim #3中，我们利用人类近端肾小管上皮细胞（hPRTE细胞）开发了一种全新的体外系统，可以生成模拟人类尿路特征的任何氨基/新糖苷的浓度-时间谱。通过对hPRTE细胞内药物量随时间的变化进行量化，并观察细胞凋亡或坏死情况，我们可以得出药物暴露、持续时间与肾毒性事件发生之间的关系。暴露与效应和毒性之间的关系允许探索剂量和持续时间，以同时优化这些关系（最大效应/最小毒性）。在Specific Aim # 4中，我们将采用种群PK模型和蒙特卡罗模拟来确定最佳药物剂量。我们的目标是将至少2个分子以最佳剂量/治疗持续时间带入NDA。多重耐药生物已经成为医院获得性感染患者的一个巨大问题。我们打算优化开发新的氨基糖苷类抗生素（neoglycosides）以满足这一需求，并为特定药物的治疗提供新产品，如鼠疫、炭疽和病原体如马尔氏伯克氏菌和假马尔氏菌。我们打算确定一种具有广谱的药物来解决与许多这些病原体相关的感染问题。然而，由于铜绿假单胞菌和不动杆菌具有特别的耐药性，因此难以在ICU环境中对严重感染的患者进行治疗，因此本提案的目的是确定一种专门针对这些后一种病原体进行优化的极有效活性的药物。

DESCRIPTION (provided by applicant): Multi-drug resistance in Gram-negative bacteria is a common problem in infected patients in the ICU environment. With Pseudomonas aeruginosa and Acinetobacter spp. it is not an uncommon event for there to be no antibiotics active for the organism, essentially returning us to the pre-antibiotic era. Resistance has also been defined in Select Agents, such as aminoglycoside resistance in Yersinia pestis in Madagascar. Achaogen has developed several series of new aminoglycoside antibiotics (neoglycosides). These agents have markedly improved activity against a wide variety of multi-resistant Gram-negative bacilli and also against Methicillin-Resistant Staphylococcus aureus (MRSA). In a different series, lead compounds have been identified with potent activity against Pseudomonas aeruginosa and Acinetobacter spp. It is the intent of this proposal to examine up to five of these molecules over the span of the proposal, rank order them and, for at least two of the molecules, to progress them into New Drug Applications. Aminoglycosides have become less used because of increasing resistance and their potential to cause nephrotoxicity. These neoglycosides obviate a great deal of the problems associated with resistance. In Specific Aim #1, we will employ our hollow fiber infection model to study candidate molecules. We can identify exposure targets that will result in optimal bacterial cell kill and suppression of resistant bacterial subpopulations. These targets will be identified through application of innovative large mathematical mixture models. In Specific Aim # 2, we will employ two animal models to validate these exposure targets. Because of the difference between murine and human half lives, we will employ a novel method of "humanizing" the drug administration in all animal models. These include a murine model of Gram-negative pneumonia and mouse thigh infection as a surrogate for skin/skin structure infection. This latter model will be run in both neutropenic and normal conditions. We will apply another completely novel model to all data, to understand pathogen kill by granulocytes. We will validate exposure targets from SA #1 with an understanding of the granulocyte impact. In Specific Aim #3, we developed a completely novel in vitro system with human proximal renal tubular epithelial cells (hPRTE cells) allowing generation of a concentration-time profile for any amino/neoglycoside that mimics the human urinary tract profile. By quantifying the amount of drug inside hPRTE cells over time and observing for apoptosis or necrosis, we can derive a relationship between drug exposure, duration and nephrotoxic event occurrence. Relationships between exposure and both effect and toxicity allows exploration of doses and durations to optimize these relationships simultaneously (maximal effect/ minimal toxicity). In Specific Aim # 4, we will employ population PK modeling with Monte Carlo simulation to identify optimal drug doses. Our aim is to bring at least 2 molecules to NDA with optimal doses/durations of therapy. Multi-resistant organisms have become a huge problem in patients with hospital-acquired infections. We intend to optimize the development of new aminoglycoside antibiotics (neoglycosides) to address this need and also to provide new products for the therapy of Select Agents, such as Plague, Anthrax and pathogens such as Burkholderia mallei and pseudomallei. We intend to identify an agent with very broad spectrum to address the infection problems associated with many of these pathogens. However, because Pseudomonas aeruginosa and Acinetobacter spp. are especially resistant and, hence, difficult to treat in seriously infected patients in the ICU setting, it is an aim of this proposal to identify an agent that is specifically optimized for extremely potent activity against these latter pathogens.