Pediatric toxicity and efficacy in long-term systemic treatment with anti-sense

描述(申请人提供)：Duchenne肌营养不良症是最常见的单基因儿童先天错误，全世界每3500名活产男性中就有一人受到影响。治疗DiViD最有前景的分子治疗方法是全身注射反义寡核苷酸(AO)，药物改变mrna的剪接，并将帧外缺失的功能转录本转换为能够产生半功能性(Becker样)的框内转录本。 营养不良蛋白。在Duchenne营养不良的大动物(狗)模型中，我们已经证明静脉(IV)给药高 剂量吗啉氧能够将营养不良蛋白的产量恢复到野生型水平的约20%，并导致多种功能、组织学和成像结果指标的稳定或改善(Yokota等人)。2009年)。针对外显子51的初步人体临床试验表明，直接肌肉注射和静脉注射都可以导致Dystrophin的产生。然而，预计重复剂量20毫克/公斤-100毫克/公斤可能需要持续的疗效。由申请者赞助的小鼠和非人类灵长类动物的GLP毒性研究表明，每周大剂量静脉注射可导致药物在肾脏近端小管细胞中积聚。这种积聚在停止给药后消失，肾脏损害的标准标记物没有升高。然而，DiViD患者的服药需要是终生的，而且还没有优化的服药计划或药物浓度来平衡肌肉和肾脏积累的疗效。在这里，我们聚集了一个跨学科的团队来定义吗啡剂量的治疗窗口。项目1与正在进行的剂量范围临床试验合作，通过尿液生物标记物和脱落的肾脏细胞来监测肾脏毒性。项目2定义了AO浓度和给药方案对药物在肾小管细胞中累积的影响，并开展了一个生物标记物发现计划，以确定敏感和可靠的尿液中吗啡相关细胞损伤的生物标记物。项目3使用已建立的小鼠药物测试核心，定义了能够在肌营养不良症小鼠模型中提供持续临床疗效的最佳给药方案。肾脏毒理学评估核心为这些项目提供支持。

DESCRIPTION (provided by applicant): Duchenne muscular dystrophy is the most common monogenic pediatric inborn error, affecting one in 3,500 live born males world-wide. The most promising molecular therapeutic approach for DIVID is systemic delivery of anti-sense oligonucleotides (AOs), where the drugs alter mRNA splicing, and converting out-of-frame loss-off function transcripts to in-frame transcripts capable of producing semi-functional (Becker-like) dystrophin. In the large animai (dog) model of Duchenne dystrophy, we have shown that intravenous (iV) delivery of high dose morpholino AOs is able to rescue dystrophin protein production to about 20% of wild-type levels, and cause stabilization or improvement of multiple functional, histological, and imaging outcome measures (Yokota et al. 2009). Initial human clinical trials using morpholino AO directed at exon 51 have shown that both direct intramuscular injection and IV administration can result in de novo dystrophin production. However, it is anticipated that repeated doses of 20 mg/kg - 100 mg/kg are likely required for sustained efficacy. GLP toxicity studies in mice and non-human primates, sponsored by the applicants, have shown that high dose weekly IV injections can lead to accumulation of drug in kidney proximal tubule cells. This accumulation resolved after termination of dosing, and there were no elevation of standard markers of kidney damage. However, dosing of DIVID patients will need to be life-long, and there has been no optimization of dosing schedules or drug concentrations that balance efficacy in muscle vs. kidney accumulation. Here, we bring together an interdisciplinary team to define the therapeutic window of morpholino dosing. Project 1 collaborates with an ongoing dose-ranging clinical trial to monitor kidney toxicity through urine biomarkers and shed renal cells. Project 2 defines the effects of AO concentrations, and dosing regimen on drug accumulation in kidney tubule cells, and also carries out a biomarker discovery program to define sensitive and reliable urine biomarkers for morpholino-associated cell damage. Project 3 defines the optimal dosing regimen able to provide sustained clinical efficacy in the mouse model of muscular dystrophy, using an established murine drug-testing core. A kidney toxicology assessment core supports these projects.