Chemotherapy-free cure of hemoglobin disorders through base editing

通过碱基编辑无需化疗即可治愈血红蛋白疾病

基本信息

批准号：
10754114
负责人：
Daniel Evan Bauer
金额：
$ 80.77万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10754114
关键词：
Address Affect Allogenic Amino Acids Antigens Autologous Autologous Transplantation Biological Assay Bone Marrow Bone Marrow Purging Bypass Cell Transplantation Cells Clinic Clinical Clinical Trials Clustered Regularly Interspaced Short Palindromic Repeats Coupling Cytokine Receptors DNA Damage Data Defect Development Disease Drug Kinetics Endowment Engineering Engraftment Epitopes Erythroid Cells Extracellular Domain FLT3 gene Face Fetal Hemoglobin Future Gene Modified Gene Transfer Genetic Genetic Engineering Globin Goals Guide RNA Hair Hematological Disease Hematology Hematopoiesis Hematopoietic Hematopoietic Stem Cell Transplantation Hematopoietic stem cells Hemoglobin Hemoglobinopathies Homologous Transplantation Human IL3RA gene Immune Immunotherapy Immunotoxins Infection Infertility Infusion procedures Intervention Life Ligands Malignant Neoplasms Measurable Medical Modeling Modification Monoclonal Antibodies Mucositis Nature Nausea Parameter Estimation Pathologic Patients Pharmaceutical Preparations Physiological Pre-Clinical Model Production Radiation therapy Regimen Regulation Resistance Risk Sickle Cell Anemia Specificity System Testing Therapeutic Therapeutic antibodies Time Toxic effect Transfusion Translations Transplantation Treatment Efficacy Validation base editing beta Thalassemia cellular engineering chemotherapy chimeric antigen receptor T cells clinical efficacy conditioning curative treatments derepression efficacy validation gene therapy genome-wide genotoxicity hemoglobin B innovation manufacturing process new technology novel strategies nuclease preservation protein function receptor research clinical testing response scale up sickling stem cell engraftment tool

项目摘要

PROJECT SUMMARY Sickle cell disease (SCD) and transfusion-dependent b-thalassemia (TDT) are severe, prevalent blood disorders for which fetal hemoglobin (HbF) induction can bypass the fundamental hemoglobin defects and hematopoietic stem/progenitor cell (HSPC) transplantation (HSCT) offers curative potential. Allogeneic and autologous trans- plant approaches can succeed, nonetheless, the short- and long-term toxicities of genotoxic alkylating chemo- therapy-based conditioning regimens remain a substantial barrier to the widespread application of curative HSCT for SCD and TDT. Immunotherapies targeting HSPC antigens have been proposed as a safer conditioning strat- egy, however the pharmacokinetics of these agents currently hamper their clinical efficacy. The long-term goal of our proposal is to address this unmet medical need by developing an effective, novel strategy for the engraft- ment and progressive enrichment of autologous gene modified HSPCs in SCD and TDT by coupling non-geno- toxic immunotherapy-based myeloablation with epitope-engineering. Our central hypothesis is that precise multiplexed base editing of HbF determinants and targeted epitopes within HSPCs can endow hematopoietic lineages with both HbF induction capacity and selective resistance to monoclonal Abs or CAR-T cells without affecting protein function or regulation (so-called stealth status). We have identified defined minimal amino-acid changes within the extracellular domains (ECD) of the cytokine receptors KIT, FLT3 and IL3RA, each expressed in long-term repopulating HSCs, that abrogate recognition by therapeutic Abs while preserving physiologic responses to stimulation with their respective ligands. Here, we will capitalize on these results and further expand the reach of these innovative genetic engineering tools with the objectives to i) generate “stealth” g-globin derepressed HSPCs by multiplex CRISPR-Cas base-editing; ii) validate efficacy of this approach on suitable pre-clinical models of b-hemoglobinopathy, and iii) further optimize and scale the manufacturing process for production of efficiently and precisely engineered cellular products suitable to progress to the clinic. We aim: 1) to optimize multiplex base editing approaches to simultaneously derepress HbF and engineer stealth HSPC epitopes that will generate immunotherapy resistant hematopoietic stem cells capable of ameliorating sickling and globin chain imbalance in SCD and TDT patient erythroid cells; 2) to maximize the engraftment of edited HSCs by optimizing immunotherapy regimens to enrich multiplex edited HSPCs through modeling parameters for therapeutic selection of edited HSPCs, and thereby obtaining proof-of-concept chemotherapy-free engraft- ment and selection of edited patient HSPCs; and 3) to identify conditions that produce efficient on-target base edits without measurable off-targets at clinical scale. This project will provide fundamental advancement of a new chemotherapy-free gene therapy approach to HSCT for hemoglobinopathies that should additionally have broad applicability to other hematopoietic disorders.

项目概要镰状细胞病 (SCD) 和输血依赖性 β 地中海贫血 (TDT) 是严重且普遍的血液疾病胎儿血红蛋白（HbF）诱导可以绕过基本的血红蛋白缺陷和造血功能干/祖细胞（HSPC）移植（HSCT）具有治疗潜力。植物方法可以成功，然而，遗传毒性烷基化化学物质的短期和长期毒性基于治疗的预处理方案仍然是治愈性 HSCT 广泛应用的重大障碍针对 HSPC 抗原的 SCD 和 TDT 免疫疗法已被提议作为更安全的调理策略。然而，这些药物的药代动力学目前阻碍了它们的临床疗效。我们的建议是通过制定一种有效的、新颖的移植策略来解决这一未得到满足的医疗需求。通过耦合非基因修饰的自体基因修饰的 HSPC 在 SCD 和 TDT 中的转化和逐步富集基于毒性免疫疗法的表位工程清髓术是我们的中心假设。 HSPC 内 HbF 决定簇和目标表位的多重碱基编辑可赋予造血功能具有 HbF 诱导能力和对单克隆 Abs 或 CAR-T 细胞的选择性抗性的谱系，无需我们已经确定了影响功能或调节的蛋白质（所谓的隐形状态）。细胞因子受体 KIT、FLT3 和 IL3RA 的胞外域 (ECD) 内的变化，各自表达在长期重新增殖的 HSC 中，消除了治疗性抗体的识别，同时保留了生理功能在这里，我们将利用这些结果并进一步扩展。这些创新基因工程工具的影响范围，其目标是 i) 产生“隐形”g-珠蛋白通过多重 CRISPR-Cas 碱基编辑去抑制 HSPC；ii) 验证该方法对合适的药物的功效； b-血红蛋白病的临床前模型，以及 iii) 进一步优化和规模化制造工艺生产适合临床应用的高效、精确设计的细胞产品。优化多重碱基编辑方法，同时解抑制 HbF 和设计隐形 HSPC 将产生能够改善镰状细胞的免疫治疗抗性造血干细胞的表位 SCD 和 TDT 患者红细胞中的球蛋白链失衡 2) 最大限度地提高编辑后的植入；通过建模参数优化免疫治疗方案以丰富多重编辑的 HSPC 用于编辑 HSPC 的治疗选择，从而获得概念验证的免化疗植入 3) 确定产生有效目标基础的条件该项目将在临床规模上实现无可测量脱靶的编辑。针对血红蛋白病的新的无化疗基因治疗方法 HSCT 还应具有广泛适用于其他造血系统疾病。