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) 遗传性疾病是全世界最常见的单基因疾病，甚至在 发达国家，与高发病率和缩短预期寿命相关。 造血细胞移植（HCT）在临床上被视为治疗这些疾病根本原因的一种手段 疾病——患者造血干细胞和祖细胞（HSPC）的遗传缺陷。 该方法受到大多数患者中 HLA 匹配供体的可用性的限制以及相关的 使用转导功能性 b 血红蛋白基因的自体 HSPC。 或用最近开发的基因组编辑技术进行修改将克服当前的局限性 同种异体 HCT 特别是胎儿血红蛋白自然发生的遗传性持久性的再现。 原则上，使用基因编辑对 HSPC 进行 (HPFH) 突变可以逆转这些细胞的临床表型 然而，就像同种异体 HCT 一样，仍然需要进行调节以促进移植。 迄今为止，这是通过 g 束全身照射 (TBI) 或烷化剂（例如）来完成的。 白消安具有严重毒性的风险，包括不孕、生长迟缓，并且——正如已经发生的那样 据报道，继发性恶性肿瘤是下一代移植的一个关键因素。 方法和基因治疗/编辑将是非基因毒性调理方案的开发 毒性最小，并允许同种异体或修饰的自体 HSPC 牢固植入。 策略是使用放射免疫疗法（RIT），将发射的放射性核素与靶向抗体结合 CD45，一种在除血小板和红细胞以及某些造血细胞之外的几乎所有造血细胞上表达的抗原 与 b 发射体相比，a 发射体仅通过几个细胞即可提供更高的能量。 直径可有效、精确且高效地杀死目标细胞，并将对非目标周围环境的毒性降至最低 根据我们之前的研究，astatine-211 (211At) 的半衰期为 7.2 小时，是患者应用的理想选择。 对狗的研究表明 211At-抗 CD45 RIT 可以替代 g 束 TBI 作为同种异体前的调理 HCT，我们目前正在对活动性血液恶性肿瘤患者使用 211At-抗 CD45 RIT。我们现在计划。 开发 211At-抗 CD45 RIT 作为基因修饰 HSPC 自体移植前的预处理 患有血红蛋白病的人，利用抗体的 Fc 工程进一步减少非特异性 我们勇敢地说，优化的 211At-抗 CD45 RIT 将能够植入 使用 CRISPR/Cas9 在 g-球蛋白基因位点编辑自体 HSPC，以重现 HPFH 突变，并具有 与高剂量 G 形束的标准调节相比，脱靶毒性显着降低，耐受性更好 TBI。因为我们对我们的发现的快速临床转化感兴趣并且已经收集了大量数据。 为了证明可行性，我们将在我们建立的非人类灵长类动物自体模型中测试这一假设 用于血红蛋白病的 HCT。