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: 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
• 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

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患者需要比正常水平高10倍的红细胞生成，以勉强维持与 生命，而补偿能力的下降是早逝的主要原因。因此，我们在项目中的总体目标 3是开发无细胞毒性、保存甚至增加骨髓储备的诱导HBF的方法。 我们的方法在生物学上得到了“成熟开关”的支持：来自γ的共享增强子开关- 在非胎儿红细胞生成过程中，珠蛋白(Hbg)到成人β-珠蛋白基因(Hbb)的转换，这是第一个需要 在HBG获得压抑标记。正如在项目1中检查的那样，抑制标记由以下因素催化 可药物酶，如DNMT1，并抑制这些酶有利于LCR与HBG的相互作用，产生 即使在严重的难治性SCD患者中，HBF也显著增加。此外，正如在项目中检查的那样 2，延缓红系成熟的治疗可能会扩大抑制红系成熟的成熟阶段窗口。 抑制酶，实现更大的HBF诱导，同时增加RBC产量 祖细胞，缓解了对日益减少和宝贵的骨髓干细胞储备的一些需求。如此之高 在目标1中，通过结合烟酰胺(Vit.B3)，首次在临床上评估创新但合理的概念， 它可以延缓造血成熟，但不能抑制增殖，耐受性很好，是一种主要的 补充谷氨酰胺对SCD的益处，清华地西他滨是一种新的口服生物利用型非细胞毒性药物 靶向DNMT1的药物。目标2解决了一个更明显的概念，即尽管任何HBF诱导都是 潜在的好处是，要在HBF~30%的情况下实现最大保护，可能需要联合使用 单个HBG抑制酶。核小体是染色质重塑的顶峰 重新定位在物理上拒绝访问基本的转录机器。这款能源价格昂贵 工作由ISWI家族酶执行，例如CHD4(项目1)。因此，CHD4抑制应该提供 相应的HBF诱导效价。因此，我们通过结构辅助进行了筛选和优化 设计一种一流的CHD4抑制剂-我们将评估该抑制剂诱导HBF的效力并推动 启用IND。目的1：进行口服烟酰胺(维生素B3)和清华口服液的概念验证性研究 地西他滨单独或联合治疗严重的SCD。这项概念验证研究结合了非 同时诱导HBF和增加骨髓储备的细胞毒性口服疗法将随机分配成年SCD患者 单独服用烟酰胺或口服清华地他滨有过早死亡的风险。目的2：确定HBF的诱导 小分子CHD4抑制在体外和体内的效力，以证明启用IND的研究的合理性。我们会 使用原代细胞体外系统比较新药和已建立的药物诱导HBF的效力 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和骨髓扩增的候选分子靶点 在项目1和2中确定和验证的储备，由项目3转换到诊所或朝向诊所。