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

• 批准号: 10627767
• 负责人: Yogen Saunthararajah
• 金额: $ 102.31万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10627767
• 关键词: ATPase Domain; Address; Adult; Biological Availability; 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; Enzyme Inhibition; Enzyme Repression; 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; Methods; Modeling; Molecular Target; Morbidity - disease rate; Mus; Natural experiment; Niacinamide; Nucleosomes; Oral; Outcome; Output; Patient Outcomes Assessments; Patients; Pharmaceutical Preparations; Positioning Attribute; Proliferating; 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; Water; Work; beta Globin; chromatin remodeling; cytotoxicity; design; experience; gamma Globin; hematopoietic differentiation; high risk; hydroxyurea; in vivo; infancy; inhibitor; innovation; interest; mortality; nonhuman primate; novel; novel therapeutics; pre-clinical; preservation; progenitor; small molecule

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.

摘要 SCD患者需要红细胞生成超过正常值的>10倍以勉强维持与正常值相容的血红蛋白水平。 死亡率低，补偿能力下降是早死的主要原因。因此，我们在项目中的总体目标 3是开发诱导HbF的方法，其是非细胞毒性的，并且保留或甚至增加骨髓储备。 从生物学上讲，我们的方法是“成熟开关”：从γ- 在非胎儿红细胞生成过程中，β-珠蛋白基因（HBG）向成人β-珠蛋白基因（HBB）的转变，首先需要 在HBG获得压制性标记正如在项目1中所考察的，压抑性标记是由以下因素催化的： 可药物化的酶，例如DNMT 1，并抑制这些酶有利于LCR与HBG的相互作用，产生 即使在患有严重的、HU难治性SCD的患者中，HbF也显著增加。此外，正如项目 2，延迟红细胞成熟的治疗可以潜在地扩大抑制红细胞成熟的成熟阶段窗口。 抑制酶，使更大的HbF诱导，同时增加红细胞输出每 骨髓干细胞是骨髓造血干细胞的重要组成部分。这种高度 在目标1中首次对创新但合理的概念进行了临床评价，通过将烟酰胺（维生素B3）， 其延迟造血成熟但不增殖，耐受性非常好，并且是造血干细胞的主要介导物。 补充谷氨酰胺治疗SCD的益处，THU-地西他滨是一种新型口服生物可利用的非细胞毒性药物， 针对DNMT 1的药物。目的2提出了一个更明显的概念，即尽管任何HbF诱导都是有效的， 可能有益的是，在HbF约30%的情况下实现最大保护可能需要联合以下抑制剂： 单个HBG抑制酶。核小体是染色质为阻遏而重塑的顶点 重新定位，物理上拒绝访问基础转录机器。这种能量昂贵的 工作由ISWI家族酶执行，例如，CHD 4（项目1）。因此，CHD 4抑制应该提供 HbF诱导的相应效力。因此，我们通过结构辅助筛选和优化 设计一流的CHD 4抑制剂-我们将评估这种抑制剂的HbF诱导效力， IND启用。目的1：进行口服烟酰胺（维生素B3）和口服THU-1的概念验证研究。 地西他滨单独和联合治疗重度SCD。这一概念验证研究的组合非- 诱导HbF和增加骨髓储备的细胞毒性口服治疗将随机分配成人SCD患者 单独使用烟酰胺或口服THU-地西他滨有早期死亡的风险。目的2：确定HbF诱导 体外和体内小分子CHD 4抑制效力，以证明IND使能研究的合理性。我们将 采用原代细胞离体系统比较新药物与已建立的药物的HbF诱导效力。 试剂，然后在SCD小鼠中进行评估（项目1），最后在非人灵长类动物模型中进行评估（项目2）。 因此，同时诱导HbF和增加骨髓造血干细胞的候选分子靶标是可能的。 在项目1和2中识别和验证的储备，由项目3转化为或朝向诊所。