Genome Editing Therapy for Usher Syndrome Type 3

针对 3 型亚瑟综合症的基因组编辑疗法

基本信息

批准号：
10759804
负责人：
MICHAEL C IANNUZZI
金额：
$ 28.99万
依托单位：
GENETOBE INC.
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10759804
关键词：
Acute Address Adult Animal Model Biodistribution Blindness CRISPR/Cas technology Cells Chronic Clarin-1 Classification Clinical Research Clinical Treatment Cochlear Implants Code Complementary DNA Consumption Custom Data Disease Dose Electroretinography Elements Evaluation Event Exons Eye Eye diseases Functional Imaging Gene Expression Gene Mutation Gene Silencing Genes Genome Genomic DNA Hearing Human Image Knock-in Knock-out Knowledge Labyrinth Lead Legal Blindness Measurement Mediating Messenger RNA Methods Modeling Muller&apos s cell Mus Mutation Natural History Optical Coherence Tomography Oryctolagus cuniculus Other Genetics Pathology Patients Periodicals Persons Phase Phenotype Point Mutation Rare Diseases Regulatory Element Reporting Retina Retinal Degeneration Retinitis Pigmentosa Safety Small Business Technology Transfer Research Structure Symptoms Testing Therapeutic Therapeutic Index Time Toxic effect Treatment Efficacy Usher Syndrome Usher Syndrome Type 3 Usher Syndrome Type 3A Variant Vision Wild Type Mouse Work acute toxicity adeno-associated viral vector autosome base editing causal variant clinically relevant cost design dosage early onset efficacy evaluation gene augmentation therapy gene correction gene therapy genomic locus hearing impairment improved insertion/deletion mutation insight legally blind mouse model mutant mutation correction novel overexpression pre-clinical prime editing progressive hearing loss promoter repair strategy repaired retinal imaging retinal toxicity safety assessment safety testing screening side effect single-cell RNA sequencing structural imaging subretinal injection success therapeutic development therapeutic evaluation therapeutic genome editing therapeutically effective therapy development tool treatment strategy

项目摘要

PROJECT SUMMARY/ABSTRACT Usher syndrome type 3A (USH3A), an autosomal recessive disorder, is characterized by progressive loss of hearing and vision due to a clarin-1 (CLRN1) gene mutation. A person with type 3 Usher syndrome will usually require cochlea implants by mid- to late adulthood and classified as being legally blind. The management of the chronic, progressive, severe vision loss (retinitis pigmentosa, RP) in USH3A remains a challenge. CLRN1 expression in retina is finely regulated. AAV delivered gene augmentation therapy has shown efficacy in the inner ear of USH3A mice but shown detrimental effects on retinal function in wildtype mice, indicating the right combination of AAV vector dose, promoter, and delivery method needs to be well optimized to develop a safe gene therapy for USH3A RP. However, the expression level of AAV delivered gene expression is hard to control and is subject to gene silencing over time. The alternative approach of gene editing therapy can directly repair a defective gene in the genome, result in expression under endogenous regulatory element control, and may provide a promising therapeutic strategy for treatment of USH3A RP and other genetic eye disorders. Current gene editing tools suffer from off-target safety concerns and low repair efficiency. In 2020, our group reported a novel Cas9 variant, known as meticulous integration Cas9 (miCas9), with improved knock-in (KI) efficiency and dramatically reduced undesirable on- and off-target insertion/deletion events (indels). We believe the use of miCas9 strategy will provide the safety and efficacy to enable the CLRN1 gene correction in the retina. The lack of clinically relevant animal models is the bottleneck to developing effective therapeutics for RP in USH3A. The rabbit is a classic model to study eye diseases. We recently developed rabbit models carrying the CLRN1 frameshift (CLRN1−/−) and the CLRN1N48K/N48K point mutation. Preliminary characterization of these rabbits has shown that CLRN1 mutations lead to severe progressive vision and hearing degeneration. To our knowledge these are the first USH3A translational animal models that convincingly recapitulates the progressive vision and hearing degeneration phenotype. In this STTR FAST TRACK application, taking advantage of the novel miCas9 tools and the novel rabbit models we have established, we propose to develop a gene editing therapy to treat vision loss in USH3A. In Phase1, we will characterize the eye phenotypes of the CLRN1N48K/N48K rabbits(aim1) and develop a miCas9 mediated hCLRN1 cDNA targeted integration strategy that fit for all CLRN1 mutations(aim2). Through this Phase I work, we will establish the feasibility of gene editing in the USH3A rabbit retina. In Phase II work, we will test the safety and efficacy of this USH3A gene editing therapy in our USH3A rabbit model through subretinal injection, to provide the preclinical evidence of miCas9 mediated USH3A gene editing therapy. This new knowledge has the potential to advance a first-in-class clinical treatment for Usher Syndrome Type 3A.

项目概要/摘要 Usher 综合征 3A 型 (USH3A) 是一种常染色体隐性遗传疾病，其特征是进行性进展患有 3 型亚瑟综合症的人会因 clarin-1 (CLRN1) 基因突变而丧失听力和视力。通常需要在成年中后期植入耳蜗，并被归类为法定盲人。 USH3A 患者慢性、进行性、严重视力丧失（色素性视网膜炎，RP）的治疗仍然是一个重要的任务 AAV 传递的基因增强疗法对视网膜中的 CLRN1 表达进行了精细调节。对 USH3A 小鼠的内耳显示出功效，但对野生型小鼠的视网膜功能显示出影响小鼠，表明 AAV 载体剂量、启动子和递送方法的正确组合需要良好优化开发针对 USH3A RP 的安全基因疗法，但 AAV 的表达水平却有所提高。基因表达很难控制，并且随着时间的推移会受到基因沉默的影响。编辑疗法可以直接修复基因组中的缺陷基因，使其在内源性下表达调控元件控制，可能为治疗 USH3A RP 和目前的基因编辑工具存在脱靶安全问题和修复率低的问题。 2020年，我们的团队报告了一种新的Cas9变体，称为精细整合Cas9（miCas9），提高敲入 (KI) 效率并显着减少不良的命中和脱靶情况我们相信 miCas9 策略的使用将提供安全性和有效性。启用视网膜中的 CLRN1 基因校正。缺乏临床相关的动物模型是开发有效治疗方法的瓶颈 USH3A 中的 RP 是研究眼部疾病的经典模型。携带 CLRN1 移码 (CLRN1−/−) 和 CLRN1N48K/N48K 点突变。这些兔子的研究表明，CLRN1 突变会导致严重的进行性视力和听力退化。据我们所知，这些是第一个 USH3A 转化动物模型，令人信服地概括了进行性视力和听力退化表型。在此 STTR FAST TRACK 应用程序中，利用新颖的 miCas9 工具和新颖的我们已经建立了兔子模型，我们建议开发一种基因编辑疗法来治疗视力丧失 USH3A。在第一阶段，我们将表征 CLRN1N48K/N48K 兔子的眼睛表型（aim1）并开发一个 miCas9 介导的 hCLRN1 cDNA 靶向整合策略适合所有 CLRN1 突变 (aim2)。在第一阶段工作中，我们将建立 USH3A 兔视网膜基因编辑的可行性。在第二阶段工作中，我们将通过以下方式在我们的 USH3A 兔子模型中测试这种 USH3A 基因编辑疗法的安全性和有效性：视网膜下注射，为 miCas9 介导的 USH3A 基因编辑治疗提供临床前证据。新知识有可能推动 3A 型亚瑟综合症的一流临床治疗。