Development of a direct DUX4 inhibitor for Facioscapulohumeral Muscular Dystrophy (FSHD)

开发用于面肩肱型肌营养不良症 (FSHD) 的直接 DUX4 抑制剂

基本信息

批准号：
10482575
负责人：
Ali Rayet Ozes
金额：
$ 29.96万
依托单位：
ALTAY THERAPEUTICS, INC.
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10482575
关键词：
Address Affect American Animals Antibodies Area Binding Biological Assay Cell Death Cell Survival Cells Cessation of life Clinical Clinical Trials Computer software D4Z4 DNA DNA Binding DNA Binding Domain Development Diagnosis Disease Drug Kinetics Ectopic Expression Exhibits FDA approved Face Facioscapulohumeral Facioscapulohumeral Muscular Dystrophy Genes Genetic Transcription Grant Homeobox Human Impairment Implant Individual Lead Link Measures Mesenchymal Stem Cells Messenger RNA Mus Muscle Muscle Cells Muscle Fibers Muscular Atrophy Muscular Dystrophies Myoblasts Myosin Heavy Chains Normal Cell Open Reading Frames Osteoblasts Outcome Measure PAX3 gene PAX7 gene Pathway interactions Patients Pharmaceutical Chemistry Pharmaceutical Preparations Phase Ploidies Positioning Attribute Progressive Disease Publishing Quality of life Quantitative Reverse Transcriptase PCR Reporter Shoulder Signal Transduction Skeletal Muscle Small Business Innovation Research Grant Small Interfering RNA Specificity Stains Surface Testing Therapeutic Toxic effect United States Universities Upper arm Wheelchairs Xenograft Model Xenograft procedure appropriate dose barium chloride base commercialization cytotoxic cytotoxicity drug candidate drug development effective therapy fluorescence microscope human DNA in silico in vivo inhibitor locked nucleic acid mouse model muscle degeneration myogenesis novel p38 Mitogen Activated Protein Kinase prevent protein protein interaction screening side effect small molecule small molecule inhibitor success targeted treatment therapeutic target tibialis anterior muscle transcription factor translational impact

项目摘要

Abstract/Summary Facioscapulohumeral dystrophy (FSHD) is the third most common form of muscular dystrophy affecting over 30,000 Americans. FSHD is a progressive disease where patients initially lose muscle cells in the face, shoulders and upper arms before degeneration expands to include nearly all skeletal muscles and 20% become wheelchair bound. 95% of FSHD patients display a contraction of the highly polymorphic D4Z4 repeat (FSHD1) containing an open reading frame for the transcription factor (TF) Double Homeobox 4 (DUX4). DUX4 misexpression is associated with myoblast toxicity and is thought to be the driver of FSHD. It is believed that DUX4 induces myoblast death by upregulating target genes including MBD3L2, TRIM43, ZSCAN4, and LEUTX that are not normally expressed in muscle. Although there are no FDA approved therapies for FSHD, losmapimod, a small molecule p38 inhibitor, was shown to inhibit DUX4 transcription in FSHD patient cells and demonstrated clinical benefit in several outcome measures. However, losmapimod is not specific to DUX4 and FSHD, therefore developing multiple targeted therapies with different modes of inhibition would increase the success rate in treating FSHD with minimum long term side effects. We hypothesize that targeting DUX4 will block multiple pathways and reduce muscle cell death. Although TFs like DUX4 are attractive therapeutic targets, they are challenging to target with small molecules because they lack clear binding pockets, have large surface areas important for protein-protein interactions and contain large intrinsically disordered domains. At Altay Therapeutics, we developed a platform that enables identification of small binding pockets within intrinsically disordered domains in previously undruggable TFs, allowing a novel druggable approach for targeting DUX4 and development of potent and highly specific DUX4 inhibitors (DUX4i). We completed in-silico screening and identified inhibitors that reduced DUX4 DNA binding by targeting the disordered linker domain. Importantly, these DUX4i had minimal cytotoxicity, reduced DUX4 target genes and rescued DUX4 driven cell viability, important to treat FSHD. We propose three aims to identify and characterize the most promising lead and continue our efforts to develop a viable treatment for FSHD based on inhibiting DUX4. The successful completion of our proposal is intended to nominate a lead DUX4 drug candidate with the following aims, 1) Determine DUX4 target gene inhibition with our DUX4is and measure cytotoxicity in a broader panel of normal cells 2) Determine specificity of our DUX4is against other homeobox-containing genes such as PAX3/PAX7 and measure potential non-specific inhibition of normal myoblast differentiation 3) Measure in vivo efficacy of DUX4is in mice implanted with human FSHD myoblasts in the tibialis anterior muscles (xenograft model of FSHD). We will then pursue an SBIR phase 2 grant that will include medicinal chemistry efforts and additional animal studies and ultimately commercialization of a first-in-class DUX4 inhibitor for FSHD. The development of the first direct DUX4 inhibitor will position Altay Therapeutics to initiate clinical trials in FSHD to ultimately bring a much-needed therapy.

摘要/总结面肩肱型营养不良症 (FSHD) 是第三种最常见的肌营养不良症，影响超过 30,000 名美国人。 FSHD 是一种进行性疾病，患者最初会失去面部、肩部的肌肉细胞退化之前的上臂和上臂扩展到几乎所有骨骼肌，20% 的人成为轮椅边界。 95% 的 FSHD 患者表现出高度多态性 D4Z4 重复序列 (FSHD1) 的收缩，其中包含转录因子 (TF) 双同源框 4 (DUX4) 的开放阅读框。 DUX4 错误表达是与成肌细胞毒性有关，被认为是 FSHD 的驱动因素。据信 DUX4 诱导上调靶基因（包括 MBD3L2、TRIM43、ZSCAN4 和 LEUTX）导致成肌细胞死亡通常在肌肉中表达。尽管尚无 FDA 批准的治疗 FSHD 的疗法，但洛斯马莫德（losmapimod）是一种小型药物。分子 p38 抑制剂，被证明可以抑制 FSHD 患者细胞中的 DUX4 转录，并经临床证明受益于多项结果指标。然而，losmapimod 并不特定于 DUX4 和 FSHD，因此开发具有不同抑制模式的多种靶向疗法将提高治疗的成功率以最小的长期副作用治疗 FSHD。我们假设针对 DUX4 将阻止多个途径并减少肌肉细胞死亡。尽管像 DUX4 这样的 TF 是有吸引力的治疗靶点，但它们小分子靶向具有挑战性，因为它们缺乏清晰的结合袋，具有较大的表面积对于蛋白质-蛋白质相互作用很重要，并且包含大的本质上无序的结构域。在阿勒泰治疗学方面，我们开发了一个平台，可以识别本质上的小结合袋以前不可成药的 TF 中的无序结构域，允许一种新的可成药方法来靶向 DUX4 以及开发有效且高度特异性的 DUX4 抑制剂 (DUX4i)。我们完成了计算机筛选和鉴定出通过靶向无序接头结构域来减少 DUX4 DNA 结合的抑制剂。重要的是，这些 DUX4i 具有最小的细胞毒性，减少了 DUX4 靶基因并挽救了 DUX4 驱动的细胞活力，这一点很重要治疗 FSHD。我们提出三个目标来识别和描述最有前途的领先者并继续我们的研究努力开发基于抑制 DUX4 的可行的 FSHD 治疗方法。我们的顺利完成该提案旨在提名一个主要的 DUX4 候选药物，其目标如下：1）确定 DUX4 靶点使用我们的 DUX4is 进行基因抑制并测量更广泛的正常细胞组中的细胞毒性 2) 确定我们的 DUX4 针对其他包含同源盒的基因（例如 PAX3/PAX7）的特异性并测量潜力正常成肌细胞分化的非特异性抑制 3) 测量植入小鼠中 DUX4is 的体内功效与胫骨前肌中的人 FSHD 成肌细胞（FSHD 异种移植模型）。然后我们将追求 SBIR 第 2 阶段资助将包括药物化学工作和额外的动物研究，并最终用于 FSHD 的一流 DUX4 抑制剂的商业化。第一个直接 DUX4 抑制剂的开发阿勒泰医药将启动 FSHD 临床试验，最终带来急需的治疗方法。