Delivery of PAI-1-targeted intrapleural fibrinolytic therapy for empyema

摘要 仅在美国就有大约65,000名患者出现脓胸(EMP)或 每年都有复杂的肺炎旁胸腔积液。电磁脉冲的发生率正在增加。 全世界。EMP与严重的发病率有关，死亡率约为20%，每年 患者护理成本约为5亿美元。胸膜腔内纤溶治疗(IPFT)已得到应用 60多年来加速胸腔引流，防止肺限制，但其疗效和 安全状况，特别是成年人的安全状况仍然不确定。高达15%的患者会发生出血。 目前的IPFT协议使用经验性的剂量、标签外干预，并反映了基本的 对IPFT在EMP中的调控及其发病机制的认识。这些差距已经缩小了 为EMP或其他形式的EMP患者开发更可靠和更安全的IPFT 结缔组织胸膜损伤，构成了我们项目的科学前提。我们的初步数据 活性纤溶酶原激活物抑制物1(PAI-1)作为生物标志物和治疗靶点的有效性 用于IPFT。我们提供了概念证明，并证明了三种机械上不同的形式 PAI-1靶向IPFT能有效逆转四环素诱导的兔胸膜组织。 这些干预措施可以将IPFT中的纤溶酶剂量减少多达8倍，从而 降低出血风险。我们设计了一个配套的诊断测试；纤溶潜力 检测(FPA)，以监测PAI-1靶向或其他形式的IPFT的结果。我们的假设是 以PAI-1为靶点的IPFT能有效清除EMP胸腔内组织。我们还假设 FPA可以预测PAI-1靶向IPFT的结果，并最终用于选择 最有可能受益的对象。为了验证这一假设，我们开发并表征了一种新的 肺炎链球菌兔EMP模型，模拟急性期人EMP的主要特征 (96小时)到有组织的慢性阶段(7-21天)，具有多房性组织和 明显的胸膜增厚。我们的目标是测试PAI-1靶向治疗的有效性和安全性 肺炎链球菌EMP模型中的IPFT，并确定FPA是否预测胸膜损伤 结果。这一假设将在四个具体目标上进行检验，这四个目标是：1.改善 PAI-1靶向给药治疗兔EMP的疗效2.分子水平测定 EMP胸腔内纤溶的机制及高血压性脑脊液对其影响 PAI-1上的胞外DNA靶向IPFT；3.选择PAI-1的单一最有效形式 针对EMP中的IPFT，开发并验证配套的FPA测试，使用来自 模型和患者；4.优化用于电磁脉冲的新型IPFT的结构和共配方 并对其安全性和有效性进行评价。一系列最先进的生化、生理、组织 分析和成像技术将被用来完成这项工作。我们独一无二的 多学科团队包括纤溶、胸膜损伤等领域的顶尖专家 作为药物的配方和开发。该项目解决了当前未得到满足的需求： 识别和临床前审查新的、可能更有效和更安全的IPFT候选者 和FPA对EMP的诊断，这些诊断在临床上是容易处理的，最终可能会改善 临床结果。

Summary Approximately 65,000 patients in the United States alone develop empyema (EMP) or complicated parapneumonic pleural effusions each year. The incidence of EMP is increasing worldwide. EMP is associated with serious morbidity, a mortality of about 20%, and annual patient care costs of roughly $500 million. Intrapleural fibrinolytic therapy (IPFT) has been used for over sixty years to expedite pleural drainage and prevent lung restriction, but its efficacy and safety profile, especially in adults, remains uncertain. Bleeding occurs in up to 15% of patients. Current IPFT protocols use empirically dosed, off-label interventions and reflect rudimentary knowledge about the regulation of IPFT in EMP and its pathogenesis. These gaps have slowed the development of more reliable and safer IPFT for patients with EMP or other forms of loculated pleural injury and form the scientific premise for our project. Our preliminary data validates active plasminogen activator inhibitor 1 (PAI-1) as a biomarker and therapeutic target for IPFT. We provide proof of concept and show that three mechanistically different forms of PAI-1 targeted IPFT effectively reverse tetracycline-induced pleural organization in rabbits. These interventions allow for up to an 8-fold reduction of the dose of fibrinolysin in IPFT, thereby mitigating bleeding risk. We designed a companion diagnostic test; the Fibrinolytic Potential Assay (FPA), to monitor outcomes of PAI-1-targeted or other forms of IPFT. Our hypothesis is that PAI-1 targeted IPFT can effectively clear intrapleural organization in EMP. We also posit that FPA can predict outcomes of PAI-1-targeted IPFT and ultimately be used to select the subjects most likely to benefit. To test this hypothesis, we developed and characterized a new S. pneumoniae rabbit EMP model which simulates key features of human EMP from an acute (96h) to an organized chronic (7-21 days) phase with multiloculation-like organization and significant pleural thickening. Our objective is to test the efficacy and safety of PAI-1 targeted IPFT in the S. pneumoniae EMP model and determine if the FPA predicts pleural injury outcomes. This hypotheses will be tested in four Specific Aims, which are to: 1. Improve the efficacy of IPFT in rabbit EMP using PAI-1 targeted delivery; 2. Determine the molecular mechanisms governing intrapleural fibrinolysis in EMP and the effects of high levels of extracellular DNA on PAI-1 targeted IPFT; 3. Select the single most effective form of PAI-1 targeted IPFT in EMP, develop and validate the companion FPA test using EMP fluids from the model and patients; and 4. Optimize the structure and co-formulation of a novel IPFT for EMP and evaluate its safety and efficacy. A range of state-of-the-art biochemical, physiologic, tissue analysis, and imaging techniques will be used to accomplish the work. Our unique multidisciplinary team includes leading experts in the fields of fibrinolysis, pleural injury, as well as drug formulation and development. This project addresses current unmet needs: the identification and preclinical vetting of new, potentially more effective and safer IPFT candidates and FPA diagnostics for EMP that are clinically tractable and that could ultimately improve clinical outcomes.