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.

项目摘要/摘要常染色体隐性疾病的Usher综合征3A型（USH3A）的特点是由于Clarin-1（CLRN1）基因突变而导致的听力和视力丧失。患有3型USHER综合征的人将通常需要在成年中期至晚期之前的耳蜗裂开，并被归类为法律上的盲人。这 USH3A中慢性，进行性，严重视力丧失（色素性视网膜炎，RP）的管理仍然是一个挑战。视网膜中的CLRN1表达受到细节调节。 AAV传递的基因增强疗法已有在USH3A小鼠的内耳中显示出有效性，但显示出对野生型残留功能的有害影响小鼠，表明AAV矢量剂量，启动子和输送方法的正确组合必须很好优化以开发为USH3A RP的安全基因疗法。但是，AAV的表达级别已传递基因表达很难控制，并且会随着时间的流逝而受到基因沉默。基因的替代方法编辑疗法可以直接修复基因组中的有缺陷的基因，导致内源性表达监管元件控制，并可能提供有前途的治疗策略，用于治疗USH3A RP和其他遗传性眼部疾病。当前的基因编辑工具遭受了脱靶安全问题和较低的维修费用效率。 2020年，我们的小组报告了一种新颖的CAS9变体，称为细致整合Cas9（MICAS9），具有提高的敲入（KI）效率，并大幅度降低了难以脱离的目标插入/删除事件（Indels）。我们认为，MICAS9策略的使用将提供安全和效率在视网膜中启用CLRN1基因校正。缺乏临床相关的动物模型是开发有效疗法的瓶颈 RP在USH3A中。兔子是研究眼病的经典模型。我们最近开发了兔子模型携带CLRN1框架（CLRN1 - / - ）和CLRN1N48K/N48K点突变。初步表征这些兔子中有CLRN1突变导致严重的渐进视力和听力变性。据我们所知，这些是第一个USH3A翻译的动物模型，令人信服地概括了渐进视力和听力退化表型。在此STTR快速应用中，利用了新颖的MICAS9工具和小说我们已经建立的兔子模型，我们建议开发一种基因编辑疗法，以治疗视力丧失 USH3A。在阶段1中，我们将表征CLRN1N48K/N48K兔（AIM1）的眼睛表型并发展 MICAS9介导的HCLRN1 cDNA靶向拟合所有CLRN1突变的靶向整合策略（AIM2）。通过这阶段的工作，我们将在USH3A兔视网膜中建立基因编辑的可行性。在第二阶段的工作中，我们将通过USH3A兔模型测试该USH3A基因编辑疗法的安全性和效率视网膜下注射，提供云母介导的USH3A基因编辑疗法的临床前证据。这新知识有可能推进3A型Usher综合征的第一类临床治疗。