Antisense oligonucleotide treatment for myotonic dystrophy

描述（由申请人提供）：1型肌强直性营养不良（DM1）是一种相对常见的肌肉营养不良形式。遗传基础是DMPK 3'非翻译区CTG重复序列的扩增，DMPK是一种编码蛋白激酶的基因，在骨骼、心脏、平滑肌和神经元中表达。这种不寻常的突变引起RNA优势，其中含有扩增CUG （CUG^" "）重复序列的RNA表达导致细胞功能障碍。突变RNA在核病灶中积累，并引发一系列复杂的下游事件，如RNA剪接调节中的缺陷。因此，一种有吸引力的治疗方法是通过加速有毒RNA的清除，从根源上解决问题。为此，我们建议开发针对突变的人DMPK {mut1 - hdmpk) mRNA的RNase h活性反义寡核苷酸（ASOs）。先前的研究表明，ASOs在骨骼肌和念珠菌肌中的生物分布和活性较低。相反，我们发现系统递送的ASOs在野生型小鼠的肌肉中高度活跃，当靶向保留在细胞核中的转录本时-可能是因为这是RNase H活跃的隔室。因此，我们假设cug扩增的转录本也可能在肌肉中显示出有效的敲除，因为它们也保留在细胞核中。与这一观点相一致的是，皮下注射ASO 4周后，转基因小鼠的肌肉中CUG(R)“”转录物被高效地敲低，RNA剪接紊乱被逆转，肌强直得以恢复。我们现在寻求开发最有效的，具有系统活性的ASOs，靶向mut- hDMPK转录本，用于骨骼肌和心肌的切割。开发计划要求鉴定在细胞中高度活跃的ASOs，选择在转基因小鼠中显示最佳mut1 - hdmpk敲除的ASOs，消除在啮齿动物和猴子中显示不可接受毒性的ASOs，然后使用gmp制造的药物进行IND- enabling毒理学/药理学研究。为了实现这些目标，我们已经形成了一个学术-商业合作，包括将DM1药物治疗带到临床所需的所有科学，临床，监管和制造专业知识。

DESCRIPTION (provided by applicant): Myotonic dystrophy type 1 (DM1) is a relatively common form of muscular dystrophy. The genetic basis is an expansion of CTG repeats in the 3' untranslated region of DMPK, a gene encoding a protein kinase expressed in skeletal, cardiac, and smooth muscle, and in neurons. This unusual mutation gives rise to RNA dominance, in which expression of RNA containing an expanded CUG (CUG^"'') repeat leads cell dysfunction. The mutant RNA accumulates in nuclear foci and initiates a complex cascade of downstream events, such as, defects in the regulation of RNA splicing. An attractive therapeutic approach, therefore, is to attack the problem at its root cause, by accelerating the clearance of the toxic RNA. To this end, we are proposing to develop RNase H-active antisense oligonucleotides (ASOs) targeting the mutant human DMPK {mut-hDMPK) mRNA. Previous studies have indicated that biodistribution and activity of ASOs in skeletal and candiac muscle is low. In contrast, we have found that systemically-delivered ASOs are highly active in muscle of wild-type mice, when targeted against a transcript that is retained in the nucleus - presumably because this is the compartment in which RNase H is active. We therefore postulated that CUG-expanded transcripts may also show efficient knockdown in muscle, because they also are retained in the nucleus. Consistent with this idea, subcutaneous administration of ASO for four weeks caused highly effective knockdown of CUG(R)"'' transcripts in muscle, reversal of RNA splicing derangements, and rescue of myotonia in transgenic mice. We seek now to develop optimally-effective, systemically-active ASOs that target mut- hDMPK transcripts for cleavage in skeletal and cardiac muscle. Development plans call for identification of ASOs that are highly active in cells, selection of ASOs that show optimal mut-hDMPK knockdown in transgenic mice, elimination of ASOs that show unacceptable toxicity in rodents and monkeys, and then IND- enabling toxicology/pharmacology studies using GMP-manufactured drug. To accomplish these goals we have formed an academic-commercial collaboration that includes all of the scientific, clinical, regulatory, and manufacturing expertise that is needed to bring a drug treatment for DM1 to the clinic. PUBLIC HEALTH RELEVANCE: Myotonic dystrophy is an inherited disease that causes progressive disability and premature death. No treatment is currently available that can improve the symptoms or slow the disease progression. The goal of this project is to develop a drug treatment for myotonic dystrophy.