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
