Drug Repurposing Screening for Rare and Neglected Diseases

传统药物的发现和开发平均需要12年时间，每一种到达患者手中的新药都要花费数亿美元。用现有的临床前和临床数据重新定位已批准的药物和临床阶段化合物可以大大加快这一进程，特别是对于罕见、低患病率的疾病和发展中国家普遍流行的疾病，否则制药业通常会忽视这些疾病。 我们正在应用新的技术和方法进行筛查，例如使用患者来源的诱导多能干细胞(IPS)和高含量筛查平台的基于表型细胞的疾病模型。我们的方法是与整个研究生态系统的领先研究人员合作，包括NIH、学术机构和生物制药公司。我们的目标包括：(1)确定用于分析开发的药物靶标或疾病表型；(2)用于高通量筛选的分析开发和优化；(3)药物再用途筛选，以确定降低疾病表型的活性化合物；(4)使用体外分析和动物模型确认化合物活性；以及(5)将任何新发现的候选化合物推进到临床试验，用于治疗罕见和被忽视的疾病。 我们已经为一系列治疗领域的多个项目进行了药物再用途筛选，包括罕见的遗传疾病、细菌和病毒感染性疾病以及分子靶向癌症。 视网膜色素变性(RP)是一种罕见的眼部退行性疾病，可导致早盲。我们进行了筛选，以确定有助于突变视蛋白正确折叠或清除的化合物，以用于潜在的RP治疗。Smith-Lemli-Opitz综合征(SLOS)是一种罕见的代谢疾病，由影响多个器官的胆固醇合成缺陷引起。我们在SLOS患者的原代细胞中完成了高通量筛查，使用质谱仪测量胆固醇水平，以确定潜在的新治疗候选方案。 为了确定治疗埃博拉病毒感染的有效药物组合，我们同样筛选了数千种药物组合。这导致了两种3种药物组合的鉴定，它们将所需的单独药物浓度降低到其临床人体血浆浓度。为了开发强大的高通量肝炎病毒感染的药物发现分析，我们鉴定了促进iPS细胞分化的肝细胞成熟的化合物。 多项合作涉及对耐药细菌进行筛选。我们与NIH的内部同事一起，对10株多重耐药的临床分离株进行了有针对性的药物联合筛选，包括肺炎克雷伯菌、鲍曼不动杆菌、铜绿假单胞菌、弗劳地柠檬酸杆菌、阴沟肠杆菌和大肠杆菌。已经确定了三组3-药物组合，它们广泛地抑制了这些耐药细菌的生长。在与校外合作伙伴的其他合作中，我们正在筛选其他耐药肺炎克雷伯菌(KP4640)和鲍曼不动杆菌(AB 5075)，以及莱姆病的主要原因伯氏疏螺旋体。 为了确定罕见癌症的新治疗选择，我们与NIH的壁内和壁外合作伙伴进行了许多合作。在一个项目中，我们筛选了抑制表达突变剪接因子(U2AF1-S34F突变)的细胞生长的化合物。这些剪接因子突变是反复发生的，而且总是杂合性的，它们通常涉及高度保守的蛋白质结构域中单个或几个氨基酸残基的替代，这可能是癌症发生的驱动因素。另一种蛋白质，Kinesin-14，已经成为神经母细胞瘤的抗癌药物靶点，我们已经进行了筛选，以确定抑制其功能的化合物。另一个项目的重点是利用卵巢癌细胞株进行筛选，以确定能够克服顺铂药物治疗耐药性的化合物。第三个肿瘤学合作的重点是确定更个性化的、针对患者的治疗。与NIH的同事们一起，我们使用10个患者来源的胰腺癌细胞株的批准药物库进行了抗癌药物谱筛选。

Conventional drug discovery and development takes an average of 12 years and costs hundreds of millions of dollars for each new drug that reaches patients. Repositioning of approved drugs and clinical-stage compounds with existing preclinical and clinical data can greatly expedite the process, particularly for rare, low-prevalence diseases and the more wide-spread diseases endemic to the developing world that are otherwise typically neglected by the pharmaceutical industry. We are applying new technologies and approaches for screening, such as phenotypic cell-based disease models using patient-derived induced pluripotent stem (iPS) cells and high-content screening platforms. Our approach is to collaborate with leading investigators from across the research ecosystem, including at NIH, academic institutions, and biopharmaceutical companies. Our objectives include (1) identification of drug targets or disease phenotypes for assay development; (2) assay development and optimization for high-throughput screening; (3) drug repurposing screening to identify active compounds that reduce disease phenotypes; (4) confirmation of compound activity using in vitro assays and animal models; and (5) advancement of any newly-identified candidate compounds to clinical trials for the treatment of rare and neglected diseases. We have performed drug repurposing screens for multiple projects across a range of therapeutic areas, including rare genetic disorders, bacterial and viral infectious diseases, and molecularly-targeted cancers. Retinitis pigmentosa (RP) is a rare degenerative disease of the eye that leads to premature blindness. We conducted screens to identify compounds that either aid in the proper folding or clearance of mutant opsin for the potential treatment of RP. Smith-Lemli-Opitz syndrome (SLOS) is a rare metabolic condition caused by a defect in cholesterol synthesis that affects multiple organs. We completed a high-throughput screen in primary cells derived from SLOS patients, using mass spectrometry to measure cholesterol levels, to identify potential new therapeutic candidates. To identify effective drug combinations for treatment of Ebola virus infection, we similarly screened thousands of drug combinations. This led to identification of two 3-drug combinations that reduced required individual drug concentrations to their clinical human plasma concentrations. To develop robust high-throughput drug discovery assays for hepatitis virus infection, we identified compounds that enhance maturation of differentiated hepatocytes from iPS cells. A number of collaborations have involved screening against drug-resistant bacteria. With NIH intramural colleagues, we performed targeted drug combination screens for 10 multidrug-resistant clinical isolates including Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Citrobacter freundii, Enterobacter cloacae, and Escherichia coli. Three sets of 3-drug combination have been identified that broadly suppressed the growth of these drug-resistant bacteria. In other collaborations with extramural partners, we are screening against other drug-resistant strains of K. pneumoniae (KP 4640) and A. baumannii (AB 5075), as well as Borrelia burgdorferi, the predominant cause of Lyme disease. To identify new therapeutic options for rare cancers, we have engaged in a number of collaborations with NIH intramural and extramural partners. In one project, we screened to identify compounds that inhibit the growth of cells expressing a mutant splicing factor (U2AF1-S34F mutation). These splicing factor mutations are recurrent and invariably heterozygous, and they often involve the substitution of a single or several amino acid residues in highly conserved protein domains that are likely drivers of carcinogenesis. Another protein, kinesin-14, has emerged as an anti-cancer drug target for neuroblastoma, and we have performed screens to identify compounds that inhibit its function. Another project focuses on identifying compounds that can overcome resistance to cisplatin drug therapy, using an ovarian cancer cell line for screening. A third oncology collaboration is focused on identifying more personalized, patient-specific treatments. With colleagues at the NIH, we have performed anti-cancer drug profiling screens using the library of approved drugs in 10 patient-derived pancreatic cancer cell lines.