Non-cytotoxic augmentation of fetal hemoglobin and bone marrow reserves

非细胞毒性增加胎儿血红蛋白和骨髓储备

基本信息

批准号：
10164850
负责人：
Yogen Saunthararajah
金额：
$ 102.46万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10164850
关键词：
ATPase Domain Address Adult Bioavailable Biological Biological Markers Bone Marrow CHD4 gene Cells Cessation of life Clinic Clinical Coagulation Process Cytotoxic agent DNA Modification Methylases Decitabine Drug Design Drug Targeting Drug usage Enhancers Enzymes Erythrocytes Erythroid Erythropoiesis Evaluation Family Fetal Hemoglobin Frequencies Genes Genetic Polymorphism Genetic Transcription Glutamine Goals Half-Life Hematopoietic Hematopoietic stem cells Hemoglobin Hemoglobin concentration result Hemolysis Human ISWI In Vitro Individual Inflammation Inherited Life Locus Control Region Marrow Mediator of activation protein Methods Modeling Molecular Target Morbidity - disease rate Mus Natural experiment Niacinamide Nucleosomes Oral Outcome Output Patient Outcomes Assessments Patients Pharmaceutical Preparations Protocols documentation Quality of life Randomized Recovery Refractory Regulation Repression Reserve Stem Cell Risk Safety Sickle Cell Anemia Stress Structure Supplementation System Tetrahydrouridine Time Translating Veno-Occlusive Disease Water Work beta Globin chromatin remodeling cytotoxicity design experience gamma Globin hematopoietic stem cell differentiation high risk hydroxyurea in vivo infancy inhibitor/antagonist innovation interest mortality nonhuman primate novel novel therapeutics pre-clinical preservation progenitor small molecule

项目摘要

ABSTRACT SCD patients require erythropoiesis >10-fold over normal to barely sustain hemoglobin levels compatible with life, and dwindling compensatory capacity is a major cause of early death. Therefore, our overall goal in Project 3 is to develop methods of inducing HbF that are non-cytotoxic and preserve or even increase marrow reserves. Biologically undergirding our approach is the `maturational switch': the switch of the shared enhancer from γ- globin (HBG) to the adult β-globin gene (HBB) during non-fetal erythropoiesis, a switch that first requires acquisition of repressive marks at HBG. As examined in Project 1, the repressive marks are catalyzed by druggable enzymes, e.g. DNMT1, and inhibiting these enzymes favors the LCR interaction with HBG, producing significant HbF increases even in patients with severe, HU-refractory SCD. Moreover, as examined in Project 2, treatments that retard erythroid maturation can potentially widen the maturation-stage window for inhibition of repressing enzymes, enabling greater HbF inductions while simultaneously increasing RBC output per progenitor, relieving some of the demands on dwindling and precious marrow stem cell reserve. This highly innovative but rational concept is evaluated clinically for the first time in Aim 1, by combining nicotinamide (vit.B3), which retards hematopoietic maturation but not proliferation, is very well-tolerated, and is a major mediator of the benefits of glutamine supplementation in SCD, with THU-decitabine, a novel orally bioavailable non-cytotoxic drug that targets DNMT1. Aim 2 addresses a more obvious concept, that although any HbF induction is potentially beneficial, achieving maximum protection with HbF ~30% may require combining inhibitors of individual HBG repressing enzymes. The culmination of chromatin remodeling for repression is nucleosome repositioning that physically denies access to the basal transcription machinery. This energetically expensive work is executed by ISWI family enzymes, e.g., CHD4 (Project 1). CHD4 inhibition should hence offer corresponding potency for HbF induction. We have therefore screened for and optimized through structure-aided design a first-in-class CHD4 inhibitor - we will evaluate this inhibitor for HbF inducing potency and drive toward IND-enabling. Aim 1: Conduct a proof-of-concept study of oral nicotinamide (vitamin B3) and oral THU- decitabine, alone and in combination, to treat severe SCD. This proof-of-concept study of combination non- cytotoxic oral therapy to both induce HbF and augment bone marrow reserves will randomize adult SCD patients at risk of early death to nicotinamide or oral THU-decitabine alone. Aim 2: Determine the HbF inducing potency of small molecule CHD4 inhibition in vitro and in vivo, to justify IND-enabling studies. We will employ primary cell ex vivo systems to compare the HbF inducing potency of the novel drug vs established agents, followed by evaluation in SCD mice (Project 1), and finally in non-human primate models (Project 2). Hence, candidate molecular targets for simultaneous induction of HbF and augmentation of bone marrow reserve, identified and validated in Projects 1 & 2, are translated into or toward the clinic by Project 3.

抽象的 SCD 患者需要比正常人多 10 倍的红细胞生成才能勉强维持与生命，而代偿能力下降是早逝的主要原因。因此，我们项目的总体目标。三是开发非细胞毒性的诱导 HbF 的方法，并保留甚至增加骨髓储备。从生物学角度来看，我们的方法的基础是“成熟转换”：共享增强子从 γ- 的转换在非胎儿红细胞生成过程中，珠蛋白（HBG）转变为成人β-珠蛋白基因（HBB），这一转变首先需要在 HBG 获得压抑标记正如项目 1 所研究的，压抑标记是由以下因素催化的。可药物酶，例如 DNMT1，抑制这些酶有利于 LCR 与 HBG 相互作用，产生即使患有严重 HU 难治性 SCD 的患者，HbF 也会显着升高。 2、延迟红细胞成熟的治疗可能会扩大抑制红细胞成熟阶段的窗口抑制酶，实现更大的 HbF 诱导，同时增加每单位红细胞输出祖细胞，缓解了对日益减少和宝贵的骨髓干细胞储备的高度需求。通过结合烟酰胺（vit.B3），在目标 1 中首次对创新但合理的概念进行临床评估，它延缓造血成熟但不延缓增殖，具有良好的耐受性，并且是造血功能的主要调节者使用 THU-地西他滨（一种新型口服生物可利用的非细胞毒性药物）补充谷氨酰胺对 SCD 的益处目标 2 的药物解决了一个更明显的概念，即尽管任何 HbF 诱导都是潜在有益，使用 HbF 实现最大保护 ~30% 可能需要结合以下抑制剂单个 HBG 抑制酶抑制染色质重塑的最终结果是核小体。物理上拒绝访问基础转录机制的重新定位这在能量上是昂贵的。工作由 ISWI 家族酶执行，例如 CHD4（项目 1）。因此，我们通过结构辅助筛选并优化了 HbF 诱导的相应效力。设计一流的 CHD4 抑制剂 - 我们将评估该抑制剂的 HbF 诱导效力并推动支持 IND 目标 1：进行口服烟酰胺（维生素 B3）和口服 THU- 的概念验证研究。地西他滨单独或联合治疗严重的 SCD，这是联合治疗的概念验证研究。诱导 HbF 和增加骨髓储备的细胞毒性口服疗法将随机化成年 SCD 患者单独服用烟酰胺或口服 THU-地西他滨有过早死亡的风险目标 2：确定 HbF 诱导因素。体外和体内小分子 CHD4 抑制的效力，以证明 IND 启用研究的合理性。使用原代细胞离体系统来比较新药与现有药物的 HbF 诱导效力药物，然后在 SCD 小鼠中进行评估（项目 1），最后在非人类灵长类动物模型中进行评估（项目 2）。因此，同时诱导 HbF 和增强骨髓的候选分子靶点在项目 1 和 2 中确定和验证的储备，由项目 3 转化为临床或转化为临床。