Novel AAV Variants for Diabetic Macular Edema

描述（由申请人提供）：本提案的目的是研究表达可溶性FLT-1的新型腺相关病毒（AAV）变体治疗糖尿病黄斑水肿（DME）的疗效，FLT-1是vegf介导的新生血管和血管通透性的有效抑制剂。二甲醚是糖尿病视网膜病变的一种晚期形式，是美国工作年龄人群失明的主要原因，是美国一个日益严重的公共卫生问题。已知血管内皮生长因子（VEGF）在糖尿病视网膜病变的进展中起核心作用，是一种有效的血管通透性诱导剂。使用抗vegf药物治疗在大型临床试验中显示出优于热激光的优势，正在成为治疗二甲醚的新护理标准。虽然这些VEGF抑制剂提供了一个有意义的进步比以前的治疗方法，需要频繁的玻璃体内给药代表了一个主要的缺点。AAV已成为眼科基因治疗临床应用的一种经过验证的载体，代表了一种长期、持续向眼睛输送蛋白质的有希望的策略。尽管AAV在早期临床试验中取得了成功，但AAV的趋向性限制了其在眼部的广泛应用。在微创手术后，能够有效转导整个视网膜的AAV变异的发展

DESCRIPTION (provided by applicant): The objective of this proposal is to examine the efficacy of novel adeno-associated virus (AAV) variants expressing soluble FLT-1, a potent inhibitor of VEGF-mediated neovascularization and vascular permeability, to treat diabetic macular edema (DME). DME is an advanced form of diabetic retinopathy and the leading cause of blindness among working-age Americans, representing a large and growing public health problem in the United States. Vascular endothelial growth factor (VEGF) is known to play a central role in the progression of diabetic retinopathy and is a potent inducer of vascular permeability. Pharmacotherapy using anti-VEGF agents, which has shown superiority to thermal laser in large clinical trials, is emerging as a new standard of care in the treatment of DME. Although these VEGF inhibitors provide a meaningful advance over previous therapies, the need for frequent intravitreal administrations represents a major shortcoming. AAV has emerged as a proven vector for clinical applications of ocular gene therapy and represents a promising strategy for long-term, sustained delivery of proteins to the eye. Despite its success in early clinical trials, AAV tropism limits its utility for numerous applications in the eye. The developmet of AAV variants capable of efficiently transducing the entire retina following a minimally invasive intravitreal injection would enable further applications in the clinic. We are developing soluble Flt-1 (sFLT), a highly potent (~10 pM) and naturally occurring anti- angiogenic peptide that binds and inactivates VEGF. In our preliminary data, we have identified novel AAV variants that can transfect specific cell types in the retina with high efficiency and specificity following intraviteal administration. In this Phase I proposal, we will quantify levels of sFLT produced by novel AAV variants in vivo. We will also assess and quantify vascular leakage in a rat model of diabetic retinopathy. If this Phase I project demonstrates efficacy of an AAV variant expressing sFLT, these experiments will lay the groundwork for Phase II studies to further substantiate the promise of AAV variants as a treatment for DME. PUBLIC HEALTH RELEVANCE: Diabetic macular edema (DME) is the leading cause of blindness among working-age Americans and a growing public health problem in the United States. VEGF inhibitors are emerging as a new standard of care in treating DME, but require that patients have frequent injections into their eyeball over a period of several years. We propose to develop a therapeutic based on new adeno-associated virus technology that would provide for long-term delivery of anti-VEGF therapeutics in DME without the need for frequent re-injections.