Center for Research Translation of Systemic Exon-skipping in Muscular Dystrophy

描述(申请人提供)：20世纪80年代末，杜兴氏肌营养不良症基因和蛋白的发现使人们对快速转化为合理的治疗方法寄予厚望。通过基因疗法和干细胞疗法向小鼠模型肌肉传递新的功能基因的早期报道助长了这一希望。然而，这些研究阐明了人类应用面临的非常高的障碍。治疗材料(细胞、病毒载体)不足、系统传递方面的挑战以及免疫障碍仍然是证明外源基因传递效果的障碍。另一种方法是修复患者自己的基因，作为一线实验疗法的两种创新的小分子方法已经出现：停止密码子阅读和外显子跳过。这两种方法都在进行人体临床试验，旨在诱使突变基因产生营养不良蛋白。在临床严重的DMD犬模型中，跳过外显子的方法是第一个显示多种功能结果改善的治疗方法。建议的CORT专注于外显子跳过，这是一种对大多数DMD患者充满希望的方法。外显子跳跃作为一种药物开发计划是非常复杂的。患者有不同的突变，药物必须针对共享重叠缺失的患者组进行定制。考虑到药物开发的高成本，有一种正在形成的共识，即跳过外显子应该作为一类获得药物批准。应对三种外显子特异性药物进行系统研究，以显示其安全性和有效性。针对这三种药物优化的程序和规则然后可以推广到其他不太适用的外显子特定药物，减少了监管障碍。本CORT的目标是系统地研究三种最常见的外显子特异性药物(外显子45，51.53)。项目1将确定与药物产生的框内转录本相对应的剪接保真度和蛋白质功能。项目2将使用多个实验系统优化每个外显子的序列选择，并在一年的临床前疗效研究中测试优化的药物。项目3将对靶向框内缺失(Becker肌营养不良症)进行第一次自然病史研究；这将允许通过生产相关的半功能性肌营养不良蛋白来预测临床疗效。这三个项目利用了两个研究核心：核心B(体外和体内功能分析)和核心C(分子诊断和细胞库)。

DESCRIPTION (provided by applicant): The identification of the Duchenne muscular dystrophy gene and protein in the late 1980's led to high hopes of rapid translation to rational therapeutics. Early reports of delivering new functional genes to mouse model muscle via gene therapy and stem cell therapy fueled this hope. However, these same studies illuminated the very high hurdles facing human applications. Insufficient therapeutic material (cells, viral vectors), challenges in systemic delivery, and immunological hurdles all remain barriers to demonstration of efficacy of exogenous gene delivery. An alternative approach Is to repair the patient's own gene, and two innovative small molecule approaches have emerged as front-line experimental therapeutics: stop codon read through, and exon skipping. Both approaches are In human clinical trials, and aim to coax dystrophin protein production from mutant genes. In the clinically severe dog model of DMD, the exon-skipping approach is the first therapeutic method that showed improvement of multiple functional outcomes. The proposed CORT is focusing on exon-skipping, the approach that holds promise for the majority of DMD patients. Exon skipping as a drug development program Is highly complex. Patients have different mutations, and drugs must be customized to groups of patients sharing overlapping deletions. Given the high cost of drug development, there is an emerging consensus that exon skipping should achieve drug approval 'as a class'. Three exon-specific drugs should be systematically studied, showing safety and efficacy. The procedures and rules optimized for these three drugs can then be generalized to other, less commonly applicable exon- specific drugs, with reduced regulatory hurdles. The goal of this CORT is to systematically study the three most commonly applicable exon-specific drugs (exons 45,51.53). Project 1 will determine the splicing fidelity and protein function corresponding to the In-frame transcripts generated by the drugs. Project 2 will optimize sequence selection for each exon using multiple experimental systems, and test optimized drugs in a 1 yr pre-clinical efficacy study. Project 3 will carry out the first natural history study of the targeted in-frame deletions (Becker muscular dystrophy); this will permit some prediction of clinical efficacy from production of the relevant semi-functional dystrophin proteins. These three Projects draw upon two research cores: Core B (In vitro and In vivo functional assays), and Core C (Molecular diagnostics and cell banking).