Nonmyeloablative allogeneic PBSC in globin disorders

非清髓性同种异体 PBSC 在珠蛋白疾病中的应用

• 批准号: 8344824
• 负责人: John Tisdale
• 金额: $ 137.82万
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8344824
• 关键词: Ablation; Acute; Adult; Age; Allogeneic Bone Marrow Transplantation; Allogenic; Allografting; Animal Model; Child; Chimerism; Clinical Protocols; Clinical Trials; Comorbidity; Cyclosporine; Disease; Disseminated Malignant Neoplasm; Dose; Engraftment; Erythrocytes; Family member; Frequencies; Gene Transfer; Genes; Genotype; Globin; Goals; Hematopoietic; Hematopoietic Stem Cell Mobilization; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Hemoglobinopathies; Heterozygote; Human; Immune response; Immunosuppression; Individual; Institutional Review Boards; Investigation; Life Expectancy; Lung diseases; Marrow; Modeling; Mus; Non-Malignant; Organ; Organ failure; Patients; Peripheral; Peripheral Blood Stem Cell; Phenotype; Production; Regimen; Reporting; Safety; Severities; Siblings; Sickle Cell Anemia; Sickle Cell Trait; Signal Transduction; Sirolimus; Source; Stroke; Supportive care; Testing; Thalassemia; Time; Toxic effect; Transplantation; allograft rejection; base; chronic graft versus host disease; clinical application; conditioning; design; follow-up; graft vs host disease; hydroxyurea; improved; irradiation; meetings; mortality; peripheral blood; programs; success

Hematologic disorders such as the thalassemias and hemoglobinopathies, resulting from absent/reduced or abnormal production of one or more of the globin-molecule subunits, respectively, together constitute the most prevalent group of human monogenic diseases. Strategies which aim to replace the absent or defective globin gene have long been envisioned as potentially curative, and gene transfer strategies targeting hematopoietic stem cells have been central to this goal. Certainly, allogeneic bone marrow transplantation, a form of hematopoietic stem cell based gene transfer accomplished by replacement of the entire diseased organ with that from a donor with a normal genotype, has proven curative, yet procedural toxicities limit application. In order to expand application, we have explored nonmyeloablative transplant regimens which are designed to allow engraftment of allogeneic hematopoietic stem cells without the toxicity of conventional marrow ablative conditioning. Using mobilized peripheral blood stem cells as the source, we demonstrated reliable engraftment in the absence of marrow ablation in patients with metastatic cancer and extended these observations to patients ineligible for conventional myeloablative transplantation due to comorbidities. While clearly establishing the ability to achieve hematopoietic engraftment in humans without marrow ablation, procedural toxicity, mainly in the form of graft-versus-host disease, remained too high for application to nonmalignant disorders. We therefore returned to animal models and have recently developed a low intensity conditioning regimen designed to promote tolerance to the allograft. Based upon a unique mechanism for tolerance induction, we compared the use of immunosuppression with rapamycin to that with conventional immunosuppression with cyclosporine after low dose irradiation in a murine model of mobilized peripheral blood allograft rejection. Only mice treated with rapamycin demonstrated long-term hematopoietic chimerism, and the levels achieved exceeded 75% at greater than 4 months of follow up. In anticipation of moving these observations toward clinical application for adults with sickle cell anemia, we established the safety and feasibility of peripheral blood stem cell mobilization in individuals with sickle cell trait, as these heterozygotes represent approximately half of the sibling donor pool. We have now initiated a clinical trial for adults with sickle cell anemia and thalassemia, and have screened over 120 potential subjects and accrued 11 with homozygous sickle cell disease. All 10 patients have thus far undergone transplantation with early donor hematopoietic chimerism resulting in reversion of the phenotype. Nine of 10 patients are free of sickle cell disease with complete replacement of peripheral red blood cells by donor type. There has been no acute or chronic graft versus host disease, and the mixed hematopoietic chimerism observed suggests operational tolerance. We have reported these results and are continuing accrual to better determine the success rate of our regimen. We have also moved on to test this approach in the haplo-idendtical setting.

分别由一种或多种珠蛋白分子亚基的缺失/减少或异常产生引起的血液疾病，例如地中海贫血和血红蛋白病，共同构成了最普遍的人类单基因疾病。长期以来，人们一直认为旨在替换缺失或有缺陷的珠蛋白基因的策略具有潜在的治疗作用，而针对造血干细胞的基因转移策略一直是这一目标的核心。当然，同种异体骨髓移植是一种基于造血干细胞的基因转移形式，通过用具有正常基因型的供体的器官替换整个患病器官来完成，已被证明具有治愈性，但程序毒性限制了应用。 为了扩大应用范围，我们探索了非清髓移植方案，该方案旨在允许异体造血干细胞植入，而没有传统骨髓消融调理的毒性。 使用动员的外周血干细胞作为来源，我们在转移性癌症患者中证明了在没有骨髓消融的情况下可靠的移植，并将这些观察结果扩展到因合并症而无法进行常规清髓移植的患者。 虽然明确建立了在不进行骨髓消融的情况下在人体中实现造血移植的能力，但主要以移植物抗宿主病形式出现的程序毒性对于应用于非恶性疾病来说仍然太高。 因此，我们回到动物模型，最近开发了一种低强度调理方案，旨在促进对同种异体移植物的耐受性。 基于独特的耐受诱导机制，我们在动员外周血同种异体移植排斥的小鼠模型中，将低剂量照射后雷帕霉素免疫抑制的使用与环孢菌素传统免疫抑制的使用进行了比较。只有接受雷帕霉素治疗的小鼠表现出长期的造血嵌合状态，并且在超过 4 个月的随访中达到了超过 75% 的水平。 为了将这些观察结果应用于镰状细胞性贫血成人患者的临床应用，我们确定了镰状细胞性状个体外周血干细胞动员的安全性和可行性，因为这些杂合子约占同胞供体库的一半。我们现在已经启动了一项针对患有镰状细胞性贫血和地中海贫血的成人的临床试验，并筛选了 120 多名潜在受试者，并筛选出 11 名患有纯合镰状细胞病的受试者。 迄今为止，所有 10 名患者均接受了早期供体造血嵌合的移植，导致表型逆转。 10 名患者中有 9 名没有镰状细胞病，外周血红细胞完全被供体类型替代。 没有出现急性或慢性移植物抗宿主病，观察到的混合造血嵌合表明操作耐受。我们已经报告了这些结果，并正在继续累积，以更好地确定我们治疗方案的成功率。 我们还继续在单倍体相同的环境中测试这种方法。