A Novel RNA Therapeutics Platform to Treat Facioscapulohumeral Muscular Dystrophy and other Neuromuscular Disorders

摘要： 在这个快速通道SBIR应用中，miRecule建议开发一个肌肉专用平台（Muscle-NAVTM） 用于递送治疗性寡核苷酸以治疗遗传性神经肌肉疾病。50多个继承人 神经肌肉疾病，包括肌病、肌营养不良和代谢性肌肉疾病， 被鉴定为单基因基础，由单个基因的突变引起。寡核苷酸 通过特异性靶向突变疾病，治疗提供了纠正许多这些疾病的潜力- 致病基因。仍然存在的主要限制因素是递送有效剂量的这些大亲水性微球的能力。 分子进入受影响的肌肉细胞。Muscle-NAV将直接由miRecule的抗体技术组成 与治疗性寡核苷酸缀合。抗体将靶向肌肉表达的受体， 结合后通过内吞作用诱导摄取。一旦我们的新型蛋白质和共轭化学被内吞 有助于内体逃逸至细胞质。 第三种最常见的遗传性肌肉疾病是面肩肱型肌营养不良症（FSHD） 在美国，这是一种孤儿适应症，约有20，000例患者。FSHD是由遗传性突变引起的， 双重同源框4（DUX 4）基因的不适当表达。DUX 4的异常表达是严重的， 对肌肉组织有毒，导致氧化应激和肌肉细胞凋亡，降低肌肉功能。 DUX 4是一种转录因子，不能通过传统的小分子或生物制剂直接“药物化”。 治疗学几项研究表明，反义寡核苷酸（阿索）治疗有潜力， 直接抑制DUX 4，在临床前模型中逆转肌肉病理。然而，一个重要的障碍， 发展是一种有效的执行手段。为了验证我们的Muscle-NAV平台，我们建议提供我们的 (ASO)靶向DUX 4（miRecule candidate MC-DX 4）用于治疗FSHD。 在快速SBIR的第一阶段，我们将首先发现针对10种受体的新型抗体， 肌肉表达通过噬菌体展示筛选（AIM 1）。我们将展示选择性交付， 在体外肌细胞中的敲低（AIM 2）。然后筛选肌肉特异性生物分布的五种缀合物， 在FSHD小鼠模型中的有效递送和敲低，以及在小鼠中的安全性，以选择单一先导抗体 肌肉-NAV（AIM 3）偶联物。在快速通道SBIR的第二阶段，我们将优化规模扩大、工艺流程 开发，以及Muscle-NAV和MC-DX 4（AIM 4）的CMC释放测试。我们将使用这种高质量的代理商 表征非人灵长类动物（NHP）中的PK特征、FSHD小鼠模型中的PK/PD特征，以及 大鼠MTD/剂量范围/TK曲线（AIM 5）。我们还将展示竞争优势和长期- MC-DX 4在两种FSHD小鼠模型（AIM 6）中的长期治疗功效。这些研究的完成 将创建一个引人注目的数据包，我们将使用它来营销我们的肌肉的共同开发和许可协议， NAV平台，并使我们的IND前会议MC-DX 4作为FSHD的有效治疗。

Abstract: In this Fast Track SBIR application miRecule proposes to develop a muscle-specific platform (Muscle-NAVTM) for the delivery of therapeutic oligonucleotide to treat inherited neuromuscular disorders. Over 50 inherited neuromuscular disorders including myopathies, muscular dystrophies, and metabolic muscle disorders have been identified with a monogenic underpinning, resulting from mutations in a single gene. Oligonucleotide therapeutics offer the potential to correct many of these disorders by specifically targeting the mutated disease- causing gene. A major limiting factor that remains is the ability to deliver effective doses of these large hydrophilic molecules into affected muscle cells. Muscle-NAV will be composed of miRecule’s antibody technology directly conjugated to a therapeutic oligonucleotide. The antibody will be targeted to a muscle expressed receptor that induces uptake via endocytosis upon binding. Once endocytosed our novel protein and conjugation chemistry aids in endosomal escape to the cytoplasm. The third most common inherited muscle disorder is facioscapulohumeral muscular dystrophy (FSHD) an orphan indication in the US, with about 20,000 patients. FSHD results from inherited mutations that lead to inappropriate expression of the double homeobox 4 (DUX4) gene. The aberrant expression of DUX4 is severely toxic to muscle tissues, resulting in oxidative stress and apoptosis of muscle cells degrading muscle function. DUX4 is a transcription factor and is not directly “druggable” by traditional small molecules or biologic therapeutics. Several studies have displayed that antisense oligonucleotide (ASO) therapy has the potential to directly repress DUX4, reversing muscle pathology in pre-clinical models. However, a significant hurdle for the development is an effective means of delivery. To validate our Muscle-NAV platform we propose to deliver our (ASO) targeting DUX4 (miRecule candidate MC-DX4) for the treatment of FSHD. In phase 1 of the fast track SBIR, we will first discover novel antibodies for ten receptors with selective muscle expression through phage display screening (AIM 1). We will demonstrate selective delivery and knockdown in muscle cells in vitro (AIM 2). Then screen five conjugates for muscle specific biodistribution, effective delivery and knockdown in an FSHD mouse model, and safety in mice to select a single lead antibody conjugate for Muscle-NAV (AIM 3). In phase 2 of the fast track SBIR, we will optimize scale-up, process development, and CMC release tests for Muscle-NAV and MC-DX4 (AIM 4). We will use this high-quality agent to characterize PK profiles in Non-Human Primates (NHPs), PK/PD profiles in a mouse model of FSHD, and MTD/ Dosing Range/TK profiles in rats (AIM 5). We will also demonstrate the competitive advantage and long- term therapeutic efficacy of MC-DX4 in two mouse models of FSHD (AIM 6). The completion of these studies will create a compelling data package we will use to market co-development and licensing deals for our Muscle- NAV platform, and enable our pre-IND meeting for MC-DX4 as an effective treatment for FSHD.