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

• 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
• 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

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/概要 面肩肱营养不良（FSHD）是第三种最常见的肌营养不良症， 三万美国人。FSHD是一种进行性疾病，患者最初会失去面部、肩部和颈部的肌肉细胞。 在退化扩大到几乎所有的骨骼肌和20%成为轮椅之前， 绑定95%的FSHD患者显示出高度多态性D4Z4重复序列（FSHD 1）的收缩， 转录因子（TF）双同源框4（DUX4）的开放阅读框。DUX4错误表达是 与成肌细胞毒性相关，被认为是FSHD的驱动因素。据信DUX4诱导 通过上调靶基因（包括MBD 3L2、TRIM 43、ZSCAN 4和LEUTX）而导致成肌细胞死亡，而这些基因不是 通常在肌肉中表达。虽然没有FDA批准的FSHD疗法，但losmapimod，一种小的 分子p38抑制剂显示出抑制FSHD患者细胞中的DUX4转录，并证实了临床 在多个结果指标中获益。然而，losmapimod对DUX4和FSHD不是特异性的，因此， 开发具有不同抑制模式的多种靶向治疗将提高治疗的成功率。 以最小的长期副作用治疗FSHD。我们假设靶向DUX4将阻断多个 减少肌肉细胞死亡。虽然TF如DUX4是有吸引力的治疗靶标，但它们 用小分子靶向具有挑战性，因为它们缺乏清晰的结合口袋，具有大的表面积， 对于蛋白质-蛋白质相互作用是重要的，并且包含大的内在无序结构域。在阿勒泰 在治疗学方面，我们开发了一个平台，能够识别内在的小结合口袋， 在以前不可用的TF中的无序结构域，允许一种新的靶向DUX4的可药用方法 和开发有效的和高度特异性的DUX4抑制剂（DUX4i）。我们完成了计算机模拟筛选， 鉴定了通过靶向无序接头结构域减少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DUX4靶基因并拯救DUX4驱动的细胞活力，这是重要的 治疗FSHD我们提出了三个目标，以确定和描述最有前途的铅，并继续我们的 努力开发基于抑制DUX4的FSHD的可行治疗。我们成功完成了 该提案旨在提名具有以下目的的DUX4候选药物：1）确定DUX4靶点 使用我们的DUX4is进行基因抑制，并在更广泛的正常细胞组中测量细胞毒性2）确定 我们DUX4的特异性是针对其他含有同源框的基因，如PAX3/PAX7， 3）测量DUX4is在植入的小鼠中的体内功效 与人FSHD成肌细胞在胫骨前肌（FSHD的异种移植物模型）中。我们将继续追求 SBIR第2阶段拨款将包括药物化学工作和额外的动物研究， 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 Altay Therapeutics将启动FSHD的临床试验，最终带来急需的治疗。