Development of 211Astatine-Conjugated Anti-CD45 Antibody-Based Conditioning for Hematopoietic Stem Cell Gene Therapy and Editing

用于造血干细胞基因治疗和编辑的基于 211Astatine 缀合抗 CD45 抗体的调理的开发

• 批准号: 10687021
• 负责人: HANS-PETER KIEM
• 金额: $ 86.19万
• 依托单位: FRED HUTCHINSON CANCER CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10687021
• 关键词: Address; Affect; Alkylating Agents; Allogenic; Animals; Antibodies; Antigens; Astatine; Autologous; Autologous Transplantation; Blood Platelets; Busulfan; CD45 Antigens; CRISPR/Cas technology; Canis familiaris; Cardiopulmonary; Cells; Child; Clinical; Data; Developed Countries; Development; Diameter; Disease; Dose; Dose Limiting; Engineering; Engraftment; Erythrocytes; Fc Receptor; Foundations; Gene Modified; Genes; Globin; Growth; Half-Life; Hematologic Neoplasms; Hematopoietic; Hematopoietic stem cells; Hemoglobin; Hemoglobin F Disease; Hemoglobinopathies; Hereditary Disease; Hour; IgG1; IgG2; IgG4; Immunocompetent; Immunologics; Infertility; Kidney; Life Expectancy; Liver; Longevity; Macaca; Macaca mulatta; Mendelian disorder; Modeling; Morbidity - disease rate; Mus; Mutation; Organ; PTPRC gene; Patients; Persons; Protocols documentation; Quality of life; Radioimmunotherapy; Radioisotopes; Reagent; Recovery; Regimen; Reporting; Risk; Second Primary Cancers; Series; Sickle Cell Anemia; Solid; Stroke; Technology; Testing; Thalassemia; Therapeutic antibodies; Toxic effect; Transplantation; Variant; Whole-Body Irradiation; antibody conjugate; antibody engineering; cell killing; cell type; clinical phenotype; clinical translation; cohort; conditioning; experience; gene replacement; gene replacement therapy; gene therapy; gene transplantation for gene therapy; genome editing; genomic locus; hematopoietic cell transplantation; hematopoietic engraftment; hemoglobin B; improved; in vivo; interest; liver injury; mouse model; next generation; nonhuman primate; novel; novel therapeutics; progenitor; stem cell gene therapy; transplantation therapy

ABSTRACT The inherited disorders of hemoglobin (Hb) are the most common monogenic diseases worldwide and, even in developed countries, associated with substantial morbidity and shortened life expectancy. Allogeneic hematopoietic cell transplantation (HCT) is clinically pursued as a means to treat the underlying cause of these disorders – the genetic defect in the patients’ hematopoietic stem and progenitor cells (HSPCs). However, this approach is limited by the availability of HLA-matched donors in the majority of patients and associated immunological complications. Use of autologous HSPCs either transduced with a functional b-hemoglobin gene or modified with recently-developed genome-editing technologies would overcome the current limitations of allogeneic HCT. In particular, the recapitulation of naturally-occurring hereditary persistence of fetal hemoglobin (HPFH) mutations in HSPCs using gene editing can, in principle, reverse the clinical phenotype of these disorders. However, just like with allogeneic HCT, there is still need for conditioning to facilitate engraftment of these cells. To date, this is accomplished with g-beam total body irradiation (TBI) or alkylating agents such as busulfan which carry the risk of significant toxicities including infertility, growth retardation, and – as has already been reported – secondary malignancies. Thus, a critical remaining factor for next-generation transplant approaches and gene therapy/editing will be the development of nongenotoxic conditioning regimens that have minimal toxicity and allow robust engraftment of allogeneic or modified autologous HSPCs. One promising strategy is the use of radioimmunotherapy (RIT) with a-emitting radionuclides conjugated to antibodies targeting CD45, an antigen expressed on almost all hematopoietic cells except platelets and erythrocytes and some of their progenitors. Compared to b-emitters, a-emitters deliver a higher amount of energy over just a few cell diameters for potent, precise, and efficiently targeted cell kill and minimized toxicity to non-targeted surrounding cells. With a half-life of 7.2 hours, astatine-211 (211At) is ideal for patient application. Based on our previous studies in dogs demonstrating that 211At-anti-CD45 RIT can replace g-beam TBI as conditioning before allogeneic HCT, we are currently using 211At-anti-CD45 RIT in patients with active hematologic malignancies. We now plan to develop 211At-anti-CD45 RIT as conditioning before autologous transplantation of gene-modified HSPCs for people with hemoglobinopathies, exploiting Fc engineering of antibodies to further minimize non-specific toxicities associated with RIT. We hypothesize that optimized 211At-anti-CD45 RIT will enable engraftment of autologous HSPCs edited with CRISPR/Cas9 at the g-globin gene locus to reproduce HPFH mutations and have significantly less off-target toxicities and better tolerability than the standard conditioning with high-dose g-beam TBI. As we are interested in rapid clinical translation of our findings and have already collected substantial data demonstrating feasibility, we will test this hypothesis in our established nonhuman primate model of autologous HCT for hemoglobinopathies.

抽象的 血红蛋白（HB）的遗传性疾病是全球最常见的单基因疾病，甚至在 发达国家与大量发病率相关，预期寿命缩短。同种异体 在临床上追求造血细胞移植（HCT）作为治疗这些原因的一种手段 疾病 - 患者造血茎和祖细胞（HSPC）的遗传缺陷。但是，这个 方法受到大多数患者的HLA匹配供体的可用性的限制 免疫学并发症。使用自体HSPC，要么用功能性B-丝状球蛋白基因翻译 或通过最近开发的基因组编辑技术进行修改将克服当前的局限 同种异体HCT。特别是，胎儿血红蛋白的自然遗传持久性的概括 （HPFH）使用基因编辑的HSPC突变原则上可以逆转这些突变 疾病。但是，就像同种异体HCT一样，仍然需要进行调节以促进植入 这些细胞。迄今 存在重大毒性风险在内 据报道 - 继发性恶性肿瘤。这是下一代移植的关键剩余因素 方法和基因治疗/编辑将是开发具有 最小的毒性，使同种异体或修饰自体HSPC的牢固植入。一个诺言 策略是使用放射免疫疗法（RIT）与靶向抗体偶联的A-A-A-Timitte radiuclides的使用 CD45，一种在几乎所有造血细胞上表达的抗原 他们的祖先。与b-emitter相比，A-Emerters仅在几个单元格上提供更高的能量 直径，具有潜在的，精确且有效靶向细胞杀死的直径，并最小化对周围未靶向的毒性 细胞。 Astatine-211（211AT）的半衰期为7.2小时，非常适合患者使用。根据我们以前的 狗的研究表明211AT-ANTI-CD45 RIT可以在同种异体之前替代G梁TBI作为条件 HCT，我们目前正在使用活性血液学恶性肿瘤患者使用211AT-ANTI-CD45 RIT。我们现在计划 在自体移植基因修饰的HSPC之前，开发211AT-ANTI-CD45 RIT作为条件 患有血红蛋白病的人，利用抗体的FC工程以进一步最大程度地减少非特异性 与RIT相关的毒性。我们假设优化的211AT-ANTI-CD45 RIT将使 用CRISPR/CAS9在G-Globin基因基因座编辑的自体HSPC，以重现HPFH突变并具有 与高剂量G梁的标准条件相比 TBI。由于我们对我们发现的快速临床翻译感兴趣，并且已经收集了大量数据 证明可行性，我们将在我们已建立的非人类私人模型中检验这一假设 HCT用于血红蛋白病。