Evaluation of Kininostatin for Treatment of Wet AMD

描述：先进视力疗法公司（AVT）正在开发针对眼疾的新疗法，眼疾是发达国家致盲的主要原因。最初适应症为新生血管疾病、湿性老年性黄斑变性和糖尿病性增生性视网膜病变。疾病的病理生理特征是脉络膜或视网膜血管生长异常，导致血管渗漏、出血，最终导致失明。大多数治疗方法都集中在抑制血管内皮生长因子（VEGF），这是一种主要的血管生成刺激。其中一种需要直接向眼部反复注射的治疗方法在最初的临床试验中显示出希望，但最近的三期数据令人失望。多种促血管生成因子与眼部新生血管形成有关，仅以一种刺激为目标，VEGF可能不足以抑制这一过程。因此，需要一种更好的输送系统和治疗方法。AVT开发了一种新的慢病毒基因转移载体，在单次眼内给药后，将为视网膜提供治疗性蛋白质的持续递送。此外，AVT已经确定了一种新的抗血管生成药物，kininostatin，其作用机制导致内皮细胞功能的抑制，不依赖于血管生成刺激。AVT的策略是将其基因传递系统与动肌抑制素相结合，以快速开发和销售一种治疗眼部疾病的优越产品。这个第一阶段的项目有四个具体目标。1)肌动抑制素表达质粒的生成与优化，包括肌动抑制素蛋白分泌和生物活性的体外评价。肌动蛋白抑制素是高分子量肌动蛋白原的蛋白水解裂解片段，是一种丰富的多功能血浆蛋白，通常不从细胞分泌。因此，在载体生成之前，优化kininostatin表达盒可能是必要的。2)编码激肌抑制素的BIV载体的生成和质量控制测试，包括激肌抑制素分泌和生物活性的验证。3)开发肌动抑制素载体体外和体内评估所需的检测方法，包括肌动抑制素特异性ELISA和免疫组织化学检测。4)视网膜下注射动肌抑制素载体对相关鼠眼新生血管模型的疗效评价。新血管形成/血管渗漏的抑制将通过荧光素血管造影和组织学分析等几种方法进行评估。II期研究将重点关注载体在第二种啮齿动物眼新生血管模型和非人类灵长类动物中的功效评估、临床前安全性研究、载体下游加工和产品制造。I期和II期研究的目的是为IND提交和I期临床试验的启动积累足够的数据。

DESCRIPTION: Advanced Vision Therapies, Inc. (AVT) is developing novel therapies for ocular disorders that are the major causes of blindness in the developed world. The initial indications are the neovascular diseases, wet age-related macular degeneration and diabetic proliferative retinopathy. Disease pathophysiology is characterized by abnormal blood vessel growth in the choroid or retina resulting in vessel leakage, hemorrhage, and ultimately to blindness. Most therapies are focused on inhibiting vascular endothelial growth factor (VEGF), a major angiogenic stimulus. One such therapy, which required repeated injections directly into the eye, showed promise in initial clinical trials, but recent Phase III data have been disappointing. A variety of pro-angiogenic factors have been implicated in ocular neovascularization, and the targeting of only one stimulus, VEGF, may not be sufficient to inhibit this process. Therefore, a better delivery system and therapeutic are required. AVT has developed a novel lentiviral gene transfer vector that following a single intra-ocular administration, will provide sustained delivery of a therapeutic protein to the retina. In addition, AVT has identified a novel anti-angiogenic agent, kininostatin, whose mechanism of action results in inhibition of endothelial cell function, independent of the angiogenic stimulus. The AVT strategy is to combine its gene delivery system with kininostatin to rapidly develop and market a superior product for treatment of ocular disease. There are four specific aims for this Phase I project. 1) Generation and optimization of kininostatin expression plasmids including in vitro evaluation of kininostatin protein secretion and biological activity. Kininostatin is a proteolytic cleavage fragment of high-molecular weight kininogen, an abundant, multifunctional plasma protein, and is not normally secreted from cells. Therefore, optimization of the kininostatin expression cassettes may be warranted prior to vector generation. 2) Generation and quality control testing of a BIV vector encoding kininostatin including verification of kininostatin secretion and biological activity. 3) Development of assays required for in vitro and in vivo evaluation of kininostatin vectors, including a kininostatin-specific ELISA and immunohistochemistry assay. 4) Efficacy evaluation of the kininostatin vector following subretinal injection into a relevant rodent model of ocular neovascularization. Inhibition of neovascularization/vascular leakage will be evaluated through several methods including fluorescein angiography and histological analyses. The Phase II studies will focus on vector efficacy evaluation in a second rodent model of ocular neovascularization and in non-human primates, preclinical safety studies, vector downstream processing and product manufacturing. The objective of the Phase I and II studies is to accrue sufficient data for IND submission and initiation of a Phase I clinical trial.