Gene therapy in canine myotubular myopathy for clinical translation

犬肌管肌病的基因治疗的临床转化

• 批准号: 8875742
• 负责人: Martin K Childers
• 金额: $ 77.95万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8875742
• 关键词: Address; Affect; Affinity; Aftercare; Animal Model; Animals; Biochemical; Biodistribution; Biological Assay; Breathing; Breeding; Canis familiaris; Centronuclear myopathy; Cessation of life; Characteristics; Clinical; Clinical Trials; Collaborations; Contralateral; Coupling; Data; Development; Dose; Engineering; Failure; Female; Genes; Goals; Health; Histopathology; Human; Hybrids; Immune response; Injection of therapeutic agent; International; Intravenous infusion procedures; Knockout Mice; Life Expectancy; Limb structure; Liver; Lower Extremity; Measurement; Mediating; Modeling; Molecular; Mus; Muscle; Muscle Weakness; Mutation; Outcome Measure; Palliative Care; Pathology; Patients; Phenotype; Physiological; Protein phosphatase; Recombinant adeno-associated virus (rAAV); Respiratory Muscles; Respiratory Stimulants; Respiratory physiology; Safety; Saline; Series; Serotyping; Skeletal Muscle; Specificity; Striated Muscles; Symptoms; System; Testing; Tourniquets; Transgenes; Translations; Ventilator; X-linked myotubular myopathy; adeno-associated viral vector; congenital muscle disorder; effective therapy; gene replacement; gene replacement therapy; gene therapy; head-to-head comparison; improved; male; mutant; myotubularin; novel; phosphatidylinositol-3-phosphatase; premature; research study; respiratory; response; translational study; vector

DESCRIPTION (provided by applicant): Mutations in myotubularin cause X-linked myotubular myopathy (XLMTM), a devastating congenital muscle disorder causing severe muscle weakness and premature death from respiratory muscle failure. Only supportive, palliative care is available. We have shown that AAV-mediated gene replacement rescued severe muscle weakness in myotubularin-deficient mice. New data show that a single systemic treatment with rAAV-MTM1 sufficed for long-term (at least one year) survival and essentially complete amelioration of symptoms of mice with myotubularin-deficient muscles. However, for eventual therapy of XLMTM patients, it is imperative to employ a predictive large animal model to refine the delivery system, assess critical safety parameters such as the potential host immune response to vector and transgene, and optimize efficacy measurements. We, therefore, developed a breeding colony in which affected male dogs display a phenotype directly analogous to human XLMTM. In preliminary studies we confirmed that local gene replacement therapy, delivered intramuscularly in the hind limb of young dogs, improved both function and pathology in myotubularin-deficient skeletal muscles. Moreover, the first XLMTM dog in which rAAV-MTM1 was delivered systemically maintained nearly normal strength in all four limbs, and normal respiratory function for more than 6 months surviving > 4 months longer than any untreated mutant dog in our colony. The positive observations in the murine and canine models drive us to focus on the development of systemic rAAV-MTM1 gene therapy. We hypothesize that modest levels of myotubularin will suffice to sustain long-term functionality of striated muscles throughout the body, including the vital respiratory muscles. We propose to utilize the canine system to test this hypothesis and to optimize vector selection (Aim 1) and dosing (Aim 2), while assessing potential safety concerns. Towards this end our Specific Aims are: Aim 1. Test systemic MTM1 gene replacement in the canine model using a novel rAAV vector (serotype 2i8) engineered for effective delivery to skeletal muscle while avoiding the liver Aim 2. Determine dose-response relationships for safety, efficacy, and immune response parameters over a period of at least 32 weeks after systemic MTM1 gene replacement in young XLMTM dogs

描述（由申请人提供）：肌管蛋白突变导致X连锁肌管性肌病（XLM TM），这是一种毁灭性的先天性肌肉疾病，可导致严重肌无力和呼吸肌衰竭导致的过早死亡。只有支持性的姑息治疗可用。我们已经证明，AAV介导的基因置换挽救了肌管蛋白缺陷小鼠的严重肌无力。新的数据表明，用rAAV-MTM 1进行的单次全身治疗足以使具有肌微管蛋白缺陷的肌肉的小鼠长期（至少一年）存活并基本上完全改善其症状。然而，对于XLMTM患者的最终治疗，必须采用预测性大型动物模型来改进递送系统，评估关键安全性参数，例如对载体和转基因的潜在宿主免疫应答，并优化疗效测量。因此，我们开发了一个繁殖群体，其中受影响的雄性犬显示出与人XLMTM直接类似的表型。在初步研究中，我们证实了局部基因替代疗法，在幼犬后肢肌内注射，改善了肌微管蛋白缺乏的骨骼肌的功能和病理。此外，第一只全身递送rAAV-MTM 1的XLMTM狗在所有四肢中保持几乎正常的力量，并且正常的呼吸功能超过6个月，比我们群体中任何未治疗的突变狗存活> 4个月。在小鼠和犬模型中的阳性观察结果促使我们专注于系统性rAAV-MTM 1基因治疗的开发。我们假设适度水平的肌管蛋白足以维持全身横纹肌的长期功能，包括重要的呼吸肌。我们建议利用犬系统来检验这一假设，并优化载体选择（目标1）和剂量（目标2），同时评估潜在的安全性问题。为此，我们的具体目标是：目标1。使用新型rAAV载体（血清型2 i8）在犬模型中测试全身性MTM 1基因置换，该载体经工程改造以有效递送至骨骼肌，同时避免肝脏Aim 2。 在幼龄XLMTM犬中进行全身性MTM 1基因替代后，确定至少32周内安全性、有效性和免疫应答参数的剂量-反应关系