Developing gene therapy strategies to treat alpha thalassemia

开发治疗α地中海贫血的基因治疗策略

• 批准号: 10545021
• 负责人: Tippi Mackenzie
• 金额: $ 71.1万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10545021
• 关键词: Address; Adult; Affect; Alleles; Binding; Biological Assay; Birth; Blood Transfusion; CRISPR screen; Caring; Cell Differentiation process; Cell Transplantation; Cells; Chronic; Chronic Disease; Clinic; Clinical; Clinical Trials; Clustered Regularly Interspaced Short Palindromic Repeats; Collaborations; Compensation; Data; Disease; Dissociation; Embryo; Engraftment; Ensure; Erythrocytes; Erythroid; Erythropoiesis; First Pregnancy Trimester; Frequencies; Gene Deletion; Gene Mutation; Genes; Globin; Grant; Guide RNA; Health; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Hemoglobin; Hemoglobin H; Hemoglobinopathies; High Pressure Liquid Chromatography; Human; Immigration; Immunodeficient Mouse; In Vitro; Initiator Codon; Institution; International; Intrauterine Blood Transfusion; Length; Lentivirus Vector; Mediating; Medical; Mendelian disorder; Morbidity - disease rate; Mus; Mutate; Neurological outcome; Nucleic Acid Regulatory Sequences; Outcome; Oxygen; PTPRC gene; Patients; Pattern; Phase I/II Clinical Trial; Production; Proteins; Regimen; Registries; Safety; Scheme; Severity of illness; Site; Specificity; Stem cell transplant; Testing; Toxic effect; Transfusion; Transgenes; Transplantation; Work; alpha Globin; alpha thalassemia major; alpha-Thalassemia; beta Globin; beta Thalassemia; derepression; design; experimental study; fetal; first-in-human; functional restoration; gamma Globin; gene replacement; gene therapy; genome editing; hematopoietic stem cell differentiation; improved; in utero; in vivo; innovation; insertion/deletion mutation; iron chelation therapy; postnatal; pre-clinical; reconstitution; repaired; restoration; southeast Asian; treatment strategy; vector; zeta Globin

ABSTRACT Alpha-thalassemia is one of the most common monogenic diseases in the world; while the carrier frequency is highest in those with South East Asian heritage, there is an expanding health burden in the US due to immigration patterns. Although the most severe form of disease, α-thalassemia major (ATM, in which all four alpha-globin genes are deleted), was formerly often lethal in utero, numerous patients are now surviving to birth after intrauterine blood transfusions, often with excellent neurologic outcomes. However, these patients have a severe chronic disease that requires monthly transfusions or a stem cell transplantation after birth. Patients with a three-gene mutation (such as those with Hemoglobin H-Constant Spring, HbH-CS) can also have severe disease requiring chronic transfusions. While several gene therapy treatments have been developed for patients with β-thalassemia, there are no such therapies for patients with the most severe forms of α-thalassemia, indicating a major unmet medical need. Due to the similarity to β-thalassemia—lack of functional hemoglobin tetramers and formation of toxic globin aggregates in absence of the corresponding binding partner—we believe we can adapt gene therapy strategies that have successfully corrected β-thalassemia in the clinic into analogous approaches for correction of α-thalassemia. These strategies include: 1) CRISPR/AAV- mediated genome editing to replace a copy of β-globin with an α-globin transgene (Aim 1, conducted by Drs. Matthew Porteus and Kyle Cromer at Stanford); 2) Lentiviral delivery of an α-globin cassette with erythroid-specific expression (Aim 2, conducted by Dr. Donald Kohn at UCLA); and 3) CRISPR- mediated de-repression of ζ-globin, the embryonic precursor to α-globin (Aim 3, conducted by Drs. Tippi MacKenzie and Bruce Conklin at UCSF). Our multi-institutional team has been actively collaborating to develop these strategies and the preliminary data presented in this grant. All three independent strategies will be developed in vitro and assessed based on their ability to normalize the globin chain imbalance and restore functional hemoglobin tetramers to α-thalassemia-derived HSCs (obtained from patients with ATM and HbH-CS cared for at UCSF). Furthermore, primary and secondary mouse transplantation experiments will be performed to ensure that edited HSCs retain their ability to engraft and reconstitute hematopoietic lineages in vivo. The expected outcome of the proposed work is a significant advancement toward a universal cure for α-thalassemia by generating substantial pre-clinical data (for one or more approaches) that may be developed into an IND with the FDA for an innovative first-in-human phase I/II clinical trial for ex vivo correction of this disease.

抽象的 α-地中海贫血是世界上最常见的单基因疾病之一；而承运人 具有东南亚血统的人的频率最高，健康负担不断扩大 the US due to immigration patterns.虽然重型 α 地中海贫血是最严重的疾病 （ATM，其中所有四个α-珠蛋白基因都被删除），以前在子宫内通常是致命的，许多 现在，患者在宫内输血后能够存活到分娩，通常神经系统状况良好 结果。然而，这些患者患有严重的慢性疾病，需要每月输血 or a stem cell transplantation after birth.具有三基因突变的患者（例如患有 血红蛋白 H-Constant Spring，HbH-CS）也可能患有需要长期输血的严重疾病。 虽然已经针对 β 地中海贫血患者开发了几种基因疗法，但 对于最严重形式的 α-地中海贫血患者，尚无此类疗法，这表明存在重大未满足的治疗方法 医疗需要。由于与β-地中海贫血相似——缺乏功能性血红蛋白四聚体和 在没有相应的结合伙伴的情况下形成有毒的球蛋白聚集体——我们相信我们 可以采用已在临床上成功纠正β地中海贫血的基因治疗策略 纠正α-地中海贫血的类似方法。 These strategies include: 1) CRISPR/AAV- 介导的基因组编辑，用 α-珠蛋白转基因取代 β-珠蛋白副本（目标 1，进行 由博士。 Matthew Porteus and Kyle Cromer at Stanford); 2) Lentiviral delivery of an α-globin cassette 具有红细胞特异性表达（目标 2，由 UCLA 的 Donald Kohn 博士进行）； 3) CRISPR- 介导 β-珠蛋白（α-珠蛋白的胚胎前体）的去抑制（目标 3，由 Drs. 进行） Tippi MacKenzie and Bruce Conklin at UCSF). Our multi-institutional team has been actively 合作制定这些战略和本次赠款中提供的初步数据。全部三个 将在体外制定独立的策略，并根据其标准化能力进行评估 珠蛋白链失衡并恢复 α-地中海贫血来源的 HSC 的功能性血红蛋白四聚体 （从 UCSF 护理的 ATM 和 HbH-CS 患者获得）。此外，初级和 将进行二次小鼠移植实验，以确保编辑后的 ​​HSC 保留其功能 体内移植和重建造血谱系的能力。 The expected outcome of the 拟议的工作是通过产生 α-地中海贫血的普遍治愈方法的重大进步 大量临床前数据（针对一种或多种方法）可开发为 IND FDA 批准一项创新的首次人体 I/II 期临床试验，用于体外纠正这种疾病。