Chemically Modified Peptide Agents for Next-Generation Conjugate Therapies to Treat Duchenne Muscular Dystrophy

用于治疗杜氏肌营养不良症的下一代结合疗法的化学修饰肽制剂

• 批准号: 9677955
• 负责人: Colin MacLaine Fadzen
• 金额: $ 1.02万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9677955
• 关键词: Chemically; Modified; Peptide; Agents; Next

Project Summary Duchenne muscular dystrophy (DMD) is a severe disease affecting approximately 1 in 3500 boys, causing profound muscle weakness and degeneration over time. The average life expectancy is 26 years of age and death is typically a result of either cardiomyopathy or respiratory infection. Very limited therapeutic options exist for the treatment of these children. DMD is caused by mutations in the gene encoding the dystrophin protein. One promising approach to treatment involves exon skipping, a process in which an antisense oligonucleotide induces the mutation-containing exon to be spliced out of the final dystrophin mRNA transcript. The FDA recently provisionally approved the first and only DMD-specific therapy, Eteplirsen, which carries out its effect via exon skipping. Eteplirsen belongs to a class of antisense therapeutics known as phosphorodiamidate morpholino oligonucleotide (PMO). Although PMOs are attractive molecules to trigger exon skipping and dystrophin restoration, their clinical efficacy has been limited by poor delivery across the cell membrane and into the nucleus. Peptides have shown promise in facilitating the nuclear delivery of cargoes. However, only a limited number of peptide sequences have been explored for the delivery of PMOs and peptides are prone to proteolytic degradation in serum. Thus, I propose to develop a peptide-based delivery platform to generate new agents for the delivery of PMOs that will enhance nuclear delivery and exon skipping and improve stability in serum. One approach will be to create linear and branched chimeras of peptide sequences, in order to explore how peptide sequence and structural diversity can improve PMO delivery. Simultaneously, a second approach will be to create macrocyclic peptides with fluorine-rich linkers, as macrocycles often confer benefits in terms of stability and delivery. These two approaches will be evaluated both in a cellular green fluorescent protein assay with a reporter PMO and in skeletal muscle cells from a mouse model of DMD with a therapeutic PMO. The compounds generated in this work will be leads for next- generation conjugate DMD therapies with improved clinical efficacy. More generally, given the ease of conjugation of these peptide-based scaffolds to other cargoes of interest, I envision that this work can be readily applied to improve other therapies for congenital diseases in which the major limiting factor is intracellular delivery.

项目摘要 杜氏肌营养不良症（DMD）是一种严重的疾病，约1/3500的男孩受到影响，造成 严重的肌肉无力和退化平均预期寿命为26岁， 死亡通常是心肌病或呼吸道感染的结果。治疗选择非常有限 是为了治疗这些孩子。DMD是由编码肌营养不良蛋白的基因突变引起的 蛋白一种有希望的治疗方法涉及外显子跳跃，这是一个反义寡核苷酸被插入外显子的过程。 寡核苷酸诱导含有突变的外显子从最终的肌营养不良蛋白mRNA转录物中剪接出来。 FDA最近临时批准了第一种也是唯一一种DMD特异性治疗药物Eteplirsen， 通过外显子跳跃来实现其作用。Eteplirsen属于一类反义疗法，称为 磷酰二胺吗啉代寡核苷酸（PMO）。虽然PMO是有吸引力的分子， 外显子跳跃和肌营养不良蛋白恢复，其临床疗效受到细胞内传递不良的限制 进入细胞核。肽在促进货物的核递送方面显示出前景。 然而，仅探索了有限数量的肽序列用于递送PMO， 肽在血清中易于蛋白水解降解。因此，我建议开发一种基于肽的递送 平台，以产生用于递送将增强核递送和外显子跳跃的PMO的新试剂 并提高在血清中的稳定性。一种方法将是创造线性和分支嵌合体的肽 序列，以探索肽序列和结构多样性如何改善PMO递送。 同时，第二种方法将是产生具有富氟接头的大环肽，如 大循环通常在稳定性和交付方面带来好处。将对这两种方法进行评估 在用报告基因PMO的细胞绿色荧光蛋白测定中和在来自 具有治疗性PMO的DMD小鼠模型。在这项工作中产生的化合物将是下一步的线索- 新一代缀合物DMD疗法具有改善的临床功效。更一般地说，考虑到 将这些基于肽的支架与其他感兴趣的货物缀合，我设想这项工作可以 易于应用于改善先天性疾病的其他疗法，其中主要限制因素是 细胞内递送。