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

描述(申请人提供)：静脉注射重组tPA仍然是中风紧急治疗中最有益的已证实的干预措施。然而，tPA再通率低、治疗时间窗短、出血转化和神经毒性等并发症是tPA临床应用的主要局限性。在这项应用中，我们提出了一个翻译计划，开发重组Annexin A2蛋白(RA2)和小剂量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卒中模型实验到临床前研究，以便在我们5年的项目结束时准备和提交IND。1.Ra2联合小剂量tPA在大鼠局灶性栓塞性卒中模型中的量程研究。2.确定最佳RA2加小剂量tPA联合治疗对远期神经预后的影响。3.量化再通/再灌注疗效，复制研究2点的神经保护作用。4.确定RA2加小剂量tPA的治疗时间窗。5.观察Ra2-小剂量-tPA联合用药对雌性和老年大鼠卒中模型的影响。6.观察Ra2-小剂量-tPA联合应用对高血压和糖尿病大鼠卒中模型的影响。7.确定RA2加小剂量tPA作为潜在的卒中治疗药物的药代动力学和毒性。8.根据疗效、药代动力学和毒性情况，提交Ra2+tPA最佳组合剂量的IND申请。在这款U01中，我们正在基于一种成熟的方法开发一种药物，即溶栓和再灌注。我们所要做的就是让tPA发挥更好的作用。我们的目标很明确。我们的里程碑是基于量化的Go-Not-Go标准。为了具有临床相关性，该药物必须改善长期的神经功能。它实际上必须像它应该的那样进行再分析。它不仅必须适用于健康的年轻男性，也必须适用于女性和有中风风险因素的动物(高血压，老年人)。它一定是安全的。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将在临床试验中追求的东西直接相关，即神经结果和成像。如果成功，这种翻译的UOI程序可能会引导我们找到一种强有力的中风治疗新方法。

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.