Membrane repair as a therapeutic intervention for treating Becker Muscular Dystrophy

项目摘要 这一合并的I/II阶段SBIR项目的目标是在将 贝克肌营养不良症(BMD)的蛋白质治疗将增强肌肉细胞的修复能力 肌营养不良蛋白基因的突变降低了表达水平，损害了肌膜 或营养不良蛋白的功能。营养不良蛋白基因的许多突变会导致BMD，而其他基因突变则会导致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 膜修复必需调节因子--三体蛋白72/MG53的构建 在骨骼肌和心肌中。众所周知，重组人MG53治疗可以改善肌营养不良症的疾病病理。 缺乏小鼠模型和其他肌肉营养不良模型，强烈表明它可能会增强 骨密度患者肌肉功能的修复与恢复。然而，最近潜在的毒性问题使最初的 重组人MG53蛋白序列不适合蛋白质治疗。因此，我们设计了一个新版本的 通过优化其功能和生化性质来治疗骨密度的重组人MG53蛋白。这是第一阶段/第二阶段 该项目将通过产生必要的数据来进一步开发这种新的蛋白质，以支持一种新的研究 通过三个具体目标向美国食品和药物管理局(FDA)提出药品(IND)申请。目标1将 制定生产这种蛋白质的化学、制造和控制(CMC)协议。系统的优化 中国仓鼠卵巢(CHO)细胞培养物的蛋白质生产将在CMO进行，该CMO专注于 CHO细胞中的蛋白质生产。我们还将对这种蛋白质进行长达24个月的稳定性测试，作为 在这一目标上的研究。可交付成果将是这种蛋白质的生产和生成的放大协议 目标2和目标3的蛋白质。目标2将完成一项临床前试验，以确定该蛋白质在治疗急性胰腺炎中的疗效。 小鼠骨密度模型。这一目标将包括在小鼠身上进行三种剂量的蛋白质的临床前疗效试验。 骨密度模型。随机分组的BMD小鼠将接受为期8-45周的治疗，并在 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。这一目标的成果将是解决蛋白质是否可以有效地治疗啮齿动物 骨密度模型。Aim 3将在小鼠身上进行蛋白质的免疫原性和毒性研究。这项评估将 涉及毒性研究，包括重复剂量研究、毒代动力学评估、代谢研究和 免疫原性评估，在BALB/c小鼠。这些研究将在Myos和一家CRO进行， 进行这类研究的历史。这里的交付内容是完成这些研究，因此数据可以 用于指导监管备案。该项目的成功完成将产生足够的数据来准备 向FDA申请IND，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.