Translational Research for Retinal Degeneration Therapies

描述（由申请人提供）：提出了一项多研究者、多中心的研究计划，目的是在RPGR突变引起的x连锁RP犬模型中完成基于基因的视网膜治疗的开发，然后再用于人类患者。这种严重的早发性人类疾病在北美约占8-10%的RP病例，在欧洲占15-20%，在单纯性患者中占25%。该应用程序建立在当前资助期间取得的成功基础上，开发了一种基于aav5的病毒载体，该载体与人类IRBP启动子和人类全长RPGR cDNA一起，在“慢”疾病模型（XLPRA1）中防止视网膜退化，或在“快”疾病模型（XLPRA2）中阻止退化并保持光感受器正常完整性。这种载体现在作为评估治疗范例的基准治疗试剂，并通过玻璃体内递送途径测试一种新的治疗方法。该应用程序将评估由RPGRORF15停止或移码突变引起的具有明显光感受器变性的狗的基因治疗，并分为3个目标，将：1-评估治疗的长期疗效，确定剂量反应范围，以确定疗效与毒性剂量；2-通过针对患者相关疾病阶段的治疗促进转译研究，使用当前资助期内建立的标准评估治疗结果；3-通过玻璃体内途径递送的改良载体进行比较疗效研究，避免受损病变光感受器的继发性手术创伤。描述了四个协调模块(M)，利用每个小组的特殊专业知识，为拟议的翻译研究创建一个互补和集中的方法。M1（大型动物实验）将制作狗模型，并为这项工作提供基础设施资源；M2（大型动物治疗）将在犬模型中进行治疗研究，并开发出用于结果评估的离体形态学措施；M3（非侵入性研究-狗模型）将建立功能和结构疾病特征，并使用适合于RPGR疾病的非侵入性结果测量方法评估治疗的成功。并将结果与离体形态学研究相关联~ M4（分子治疗发展）将为视网膜下和玻璃体内递送提供治疗载体。本应用程序中描述的研究代表了模块科学家之间长期合作的延续，该合作已经将RPE65-LCA患者的视网膜基因治疗带入了I期临床试验。宾夕法尼亚大学领导了与佛罗里达大学的合作。

DESCRIPTION (provided by applicant): A multi-investigator, multi-center research plan is proposed to finalize the development of gene-based retinal therapy in dog models of X-linked RP caused by mutations in RPGR prior to use in human patients. This uniformly severe, early onset human disease accounts for ~ 8-10% RP cases in North America, 15-20% in Europe, and 25% of simplex patients. The application builds on the success achieved during the current funding period which developed an AAV5-based viral vector that, together with the human IRBP promoter and human full-length RPGR cDNA, prevents the retina from degenerating in the 'slow' disease model (XLPRA1), or arrests the degeneration and maintains the photoreceptors at normal integrity in the 'fast' disease model (XLPRA2). This vector now serves as the benchmark therapeutic reagent for assessing treatment paradigms, and testing a novel therapeutic approach via the intravitreal route of delivery. The application will evaluate gene therapy in dogs having phenotypically distinct photoreceptor degenerations caused by stop or frameshift mutations in RPGRORF15, and is divided into 3 aims that will: 1-assess the long term efficacy of treatment and determine the dose-response range to establish efficacy vs toxicity dose~ 2- facilitate translational studies by targeting treatment to patient-relevant disease stage to assess treatment outcomes using criteria established during the current funding period~ 3- carry out comparative efficacy studies on modified vectors delivered via the intravitreal route that avoid secondary surgical trauma in compromised diseased photoreceptors. Four coordinated modules (M) are described that take advantage of the special expertise of each group to create a complementary and focused approach to the proposed translational studies. M1 (Large Animal experimental) will produce the dog models, and provide infrastructure resources for this work~ M2 (Large Animal Therapy) will carry out therapy studies in the canine models and develop ex vivo morphologic measures for outcome assessment~ M3 (Non-invasive Studies-Dog Models) will establish functional and structural disease features, and evaluate success of therapies using non-invasive outcome measures chosen appropriate for RPGR disease, and correlate the results with ex vivo morphologic studies~ M4 (Molecular Therapeutic Development) will provide therapeutic vectors for both subretinal and intravitreal delivery. The research studies described in this application represents a continuation of a longstanding collaboration between the module scientists that already has brought retinal gene therapy for RPE65-LCA patients to a Phase I clinical trial. The University of Pennsylvania leads this collaboration with the University of Florida.