Development of annexin A2 plus tPA as a novel stroke thrombolytic therapy

描述（由申请人提供）：静脉注射重组tPA仍然是卒中紧急治疗中最有益的干预措施。然而，再灌注率低、治疗时间窗短、出血转化和神经毒性并发症是tPA临床应用的主要限制。在这个应用中，我们提出了一个转化计划，开发重组膜联蛋白A2蛋白（rA2）和低剂量tPA作为急性缺血性卒中的联合溶栓治疗。我们有8个具体目标，从控制良好的大鼠栓塞性中风模型实验到IND准备的临床前研究，并在我们5年的项目结束时提交。1. rA2联合低剂量tPA在大鼠局灶性栓塞模型中的剂量范围研究。2. 确定最佳rA2 +低剂量tPA组合对长期神经预后的影响。3. 量化再通/再灌注效果并在第二个研究地点复制神经保护。4. 确定rA2加低剂量tPA的治疗时间窗。5. 观察ra2 -低剂量tpa联合用药对雌性和老年大鼠脑卒中模型的疗效。6. 观察ra2 -低剂量tpa联合治疗高血压和糖尿病大鼠脑卒中的疗效。7. 确定rA2加低剂量tPA作为潜在卒中治疗药物的药代动力学和毒性概况。8. 根据疗效、药代动力学和毒性谱，提交rA2 + tPA最佳组合剂量的IND申请。在这个U01中，我们正在开发一种基于成熟方法的药物，即血栓溶解和再灌注。我们所要做的就是使tPA更好地发挥作用。我们的目标很明确。我们的里程碑是基于量化的“去不去”标准。要具有临床意义，该药物必须改善长期的神经功能。它一定会像它应该的那样再通化。它不仅要对健康的年轻男性有效，而且要对女性和有中风危险因素（高血压、老年）的动物有效。它必须是安全的。当然，最重要的是，它必须比标准的tPA剂量更好。我们的试验数据很有希望。我们的终点和里程碑与临床试验中所追求的目标直接相关，即神经学结果和成像。如果成功，这个转化UOI项目可能会为我们提供一种强大的中风治疗新方法。

DESCRIPTION (provided by applicant): Intravenous administration of recombinant tPA remains the most beneficial proven intervention for emergency treatment of stroke. However, low reperfusion rates, short treatment time windows, and complications of hemorrhagic transformation and neurotoxicity comprise the major limitations for tPA clinically. In this application, we propose a translational plan to develop recombinant Annexin A2 protein (rA2) plus low-dose tPA as a combination thrombolytic therapy for acute ischemic stroke. We have 8 specific aims going from experiments in well-controlled rat embolic stroke models to preclinical studies for IND preparation and submission at the end of our 5-year project. 1. Dose-ranging studies for rA2 combined with low-dose tPA in a rat focal embolic stroke model. 2. Determine effects of optimal rA2 plus low-dose tPA combination in long term neurological outcomes. 3. Quantify recanalization/reperfusion efficacy and replicate neuroprotection in 2nd research site. 4. Determine the therapeutic time window of rA2 plus low-dose tPA. 5. Examine efficacy of rA2-low-dose-tPA combination in female and aged rat stroke models. 6. Examine efficacy of rA2-low-dose-tPA combination in hypertensive and diabetic rat stroke models. 7. Determine pharmacokinetic and toxicity profiles of rA2 plus low-dose tPA as a potential stroke therapeutic. 8. Submit IND application for the optimal combination dose of rA2 plus tPA based on efficacy, pharmacokinetic and toxicity profiles. In this U01, we are developing a drug based on a proven approach, i.e. thrombolysis and reperfusion. All we seek to do is to make tPA work better. Our goals are straightforward. Our milestones are based on quantitative go-no-go criteria. To be clinically relevant, the drug must improve long-term neurological function. It must actually recanalize like it's supposed to. it must work not just in healthy young males, but also in female, and animals with stroke risk factors (hypertension, aged). It must be safe. And of course, most importantly, it must be better than the standard tPA dosing. Our pilot data are promising. Our endpoints and milestones are directly related with what will be pursued in a clinical trial, i.e. neurological outcomes and imaging. If successful, this translational UOI prgram may lead us to a powerful new approach for stroke therapy.