Membrane repair as a therapeutic intervention for treating Becker Muscular Dystrophy

项目摘要 这一合并的第一/第二阶段SBIR项目的目标是实现商业化的关键里程碑， 蛋白质治疗贝克肌营养不良症（BMD），将提高肌肉细胞的修复能力 肌营养不良蛋白基因突变降低了表达水平， 或肌营养不良蛋白的功能。肌营养不良蛋白基因中的许多突变导致BMD，而其他突变导致BMD。 导致更严重的杜氏肌营养不良症（DMD）。Myos Inc.正在开发一种新的重组 三重蛋白72/Mitsugumin 53（TRIM 72/MG 53）的构建，膜修复的重要调节因子 在骨骼肌和心肌中。已知rhMG 53疗法改善肌营养不良蛋白中的疾病病理学。 缺陷小鼠模型和其他肌营养不良模型，强烈表明它可以增强 修复和恢复BMD中的肌肉功能。然而，最近潜在的毒性问题使原来的 rhMG 53蛋白序列对于蛋白质疗法而言是次优的。因此，我们设计了一个新版本的 rhMG 53蛋白通过优化其功能和生物化学性质用于治疗BMD。I/II期 该项目将进一步开发这种新的蛋白质，通过产生必要的数据，以支持一个新的研究 美国食品药品监督管理局（FDA）通过三个具体目标向美国食品药品监督管理局（FDA）提交IND申请。目标1将 开发用于生产该蛋白质的化学、生产和控制（CMC）方案。优化 中国人卵巢（CHO）细胞培养物的蛋白质生产将在CMO进行，重点是 CHO细胞中的蛋白质生产。我们还将对蛋白质进行长达24个月的稳定性测试， 在这方面的研究。交付物将是生产这种蛋白质的规模扩大方案， 目标2和目标3的蛋白质。Aim 2将完成一项临床前试验，研究这种蛋白质在治疗 小鼠BMD模型。这一目标将涉及在小鼠中进行三种剂量的蛋白质的临床前有效性试验 BMD模型。BMD小鼠的随机组群将被治疗8 - 45周，并且BMD小鼠的体重变化将被观察到。 营养不良表型将通过骨骼肌和心肌的各种测量来确定 结构和功能。这一目标的交付将是解决蛋白质是否可以有效地治疗啮齿动物 BMD模型。目的3将在小鼠中进行蛋白质的免疫原性和毒性研究。这一评估将 涉及毒性研究，包括重复给药研究、毒代动力学评估、代谢研究和 免疫原性评估。这些研究将在Myos和一家CRO进行， 进行此类研究的历史。这里的交付成果将是完成这些研究，以便数据可以 用于指导监管备案。该项目的成功完成将产生足够的数据， 向FDA提交IND申请，用于治疗BMD的临床试验。

PROJECT ABSTRACT The goal of this combined Phase I/II SBIR project is to accomplish key milestones in commercializing a protein therapeutic for Becker muscular dystrophy (BMD) that will enhance the repair capacity of muscle cell sarcolemmal membranes compromised by mutations in the dystrophin gene that reduce the expression level or function of the dystrophin protein. Many mutations in the dystrophin gene result can in BMD while others result in the more severe Duchenne muscular dystrophy (DMD). Myos Inc. is developing a novel recombinant construct of the tripartite protein 72/mitsugumin 53 (TRIM72/MG53), an essential regulator of membrane repair in skeletal and cardiac muscle. It is known that rhMG53 therapy ameliorates disease pathology in a dystrophin deficient mouse model and models of other muscular dystrophies, strongly suggesting that it may enhance repair and restoration of muscle function in BMD. However, recent potential toxicity concerns make the original rhMG53 protein sequence suboptimal for protein therapy. Therefore, we engineered a new version of the rhMG53 protein for use in treating BMD by optimizing its functional and biochemical properties. This Phase I/II project will further develop this novel protein by producing the data necessary to support an investigational new drug (IND) application to the U.S. Food and Drug Administration (FDA) through three specific aims. Aim 1 will develop Chemistry, Manufacturing, and Control (CMC) protocols for production of this protein. Optimization of protein production from Chinese Hamster Ovary (CHO) cell cultures will be conducted at a CMO focused on protein production in CHO cells. We will also conduct stability testing up to 24 months for the protein as part of the studies in this aim. The deliverables will be a scale-up protocol for production of this protein and generation of protein for aims 2 and 3. Aim 2 will complete a pre-clinical trial for the efficacy of this protein in treating a mouse model of BMD. This aim will involve a preclinical efficacy trial for three doses of the protein in a mouse model of BMD. Randomized cohorts of BMD mice will be treated with for 8-45 weeks and changes in the dystrophy phenotype will be determined through various measurements of skeletal and cardiac muscle structure and function. The deliverable for this aim will be to resolve if the protein can effectively treat a rodent model of BMD. Aim 3 will conduct immunogenicity and toxicity studies for protein in mice. This assessment will involve toxicity studies, including repeated-dose studies, toxicokinetic assessment, metabolic studies and immunogenicity assessment, in BALB/c mice. These studies will be conducted at Myos and a CRO with a long history of conducting such studies. The deliverable here will be completing these studies so the data can be used to guide regulatory filings. Successful completion of this project will result in sufficient data to prepare an IND application to the FDA for use in clinical trials for the treatment of BMD.