Toward Safer Gene Therapy for Hemophilia A

迈向更安全的 A 型血友病基因治疗

• 批准号: 10333185
• 负责人: Roland W. Herzog
• 金额: $ 257.22万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-05 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10333185
• 关键词: Address; Attention; Basic Science; Biology; Birth; Blood Coagulation Disorders; Blood Coagulation Factor; Cells; Cellular Stress Response; Clinical Research; Clinical Trials; Commercial Sectors; Communities; DNA; Development; Disease; Dose; Elements; Event; F8 gene; Factor VIII; Gene Transfer; Generations; Genetic Recombination; Genome; Goals; Grant; Hemophilia A; Hepatic; Hepatocyte; Hepatotoxicity; Human; Human Biology; Immune; Immune Tolerance; Immune response; Immune system; Immunobiology; Immunology; In Vitro; Individual; Insertional Mutagenesis; Investigation; Knowledge; Lead; Link; Liver; Molecular; Molecular Analysis; Molecular Virology; Normal Range; Outcome; Patients; Pharmacotherapy; Phase III Clinical Trials; Positioning Attribute; Probability; Production; Proteins; Protocols documentation; Research Personnel; Role; Safety; Steroids; Structure; Testing; Therapeutic; Time; Toxic effect; Transfer Factor; Transgenes; Translations; United States Food and Drug Administration; Variant; Viral; Viral Genes; adaptive immune response; adeno-associated viral vector; amyloid formation; design; endoplasmic reticulum stress; experience; gene therapy; improved; in vivo; male; mouse model; nuclease; particle; programs; protein misfolding; response; vector; vector genome

PROJECT SUMMARY ABSTRACT Gene therapy for the X-linked bleeding disorder hemophilia holds much promise to accomplish a lasting cure. Four clinical trials utilizing adeno-associated viral (AAV) gene transfer to the livers of males with severe hemophilia are currently being investigated in multiple Phase III clinical trials. Hemophilia A (deficiency in factor VIII, FVIII), the more common form of the disease (~80% of patients), has traditionally been more difficult to treat by gene therapy because FVIII is a large molecule and not efficiently expressed and secreted. Nonetheless, initial results demonstrated complete correction of the disease. However, FVIII levels declined substantially over time, raising worrying questions about durability, and patients also experienced prolonged mild hepatotoxicity despite steroid drug treatment during the first year of gene therapy. Multiple recent observations raise serious questions about the safety of hepatic gene therapy for hemophilia A. These urgently need to be addressed so that this promising approach can be safely applied to patients and to achieve sustained correction. For instance, the reasons for hepatotoxicity and for the decline in FVIII expression are unclear, highlighting critical gaps in our knowledge of the interactions between the vector and hepatocytes and between the FVIII expression and hepatocytes, as well as the role of the immune system in long-term outcome. There is also renewed concern about insertional mutagenesis. We will address these basic and mechanistic questions related to the biology of AAV and FVIII. The central hypothesis of this proposal is that multiple interconnected features of AAV and FVIII biology limit durability of therapeutic expression and pose serious safety concerns. Further, we postulate that unraveling these mechanisms will allow for design of vectors and protocols that minimize these problems, thus resulting in lasting therapy and enhanced safety. The program combines expertise in FVIII biology, cellular stress responses, immunology, and AAV vector biology and is structured into 3 scientific Projects, an administrative Core and 2 scientific Cores. Project 1 (Kaufman) seeks to overcome FVIII protein misfolding and cell toxicity. Project 2 (Xiao) will uncover the mechanisms that lead to formation of subgenomic AAV vector particles that form during vector production through nuclease and recombination activities. Project 3 (Herzog) will define the mechanisms of innate and adaptive immune responses to AAV-FVIII gene transfer. The objectives of the three projects will be supported by an administrative core (Core A), a core that provides human hepatocytes for in vitro and in vivo studies (Core B), and a core that performs development and molecular analysis of AAV vectors (Core C). Overall, this project applies the expertise of the individual investigators towards addressing major unanswered questions in FVIII biology, gene therapy for hemophilia, liver-directed gene transfer, and molecular and immunobiology of AAV vectors.

项目概要摘要 X连锁出血性疾病血友病的基因疗法有望实现持久治愈。 利用腺相关病毒 (AAV) 基因转移至患有严重疾病的男性肝脏的四项临床试验 血友病目前正在多个 III 期临床试验中进行研究。 A 型血友病（缺乏因子 VIII、FVIII）是这种疾病的更常见形式（约 80% 的患者），传统上更难治疗 通过基因治疗，因为 FVIII 是一个大分子，不能有效表达和分泌。尽管如此， 初步结果表明该疾病已完全治愈。然而，FVIII 水平大幅下降 时间，引发了关于耐久性的令人担忧的问题，并且患者还经历了长期的轻度肝毒性 尽管在基因治疗的第一年进行了类固醇药物治疗。最近的多项观察结果引起了严重的 关于甲型血友病肝基因治疗的安全性问题。这些迫切需要解决，以便 这种有希望的方法可以安全地应用于患者并实现持续的矫正。例如， 肝毒性和 FVIII 表达下降的原因尚不清楚，这凸显了我们在 了解载体与肝细胞之间以及 FVIII 表达与肝细胞之间相互作用的知识 肝细胞，以及免疫系统在长期结果中的作用。也有新的担忧 关于插入突变。我们将解决这些与生物学相关的基本和机制问题 AAV 和 FVIII。该提案的中心假设是 AAV 和 FVIII 的多个相互关联的特征 生物学限制了治疗表达的持久性并造成严重的安全问题。此外，我们假设 解开这些机制将允许设计能够最大限度地减少这些问题的载体和协议，从而 从而实现持久治疗并提高安全性。该项目结合了 FVIII 生物学、细胞应激方面的专业知识 反应、免疫学和 AAV 载体生物学，分为 3 个科学项目、一个行政项目 核心和 2 个科学核心。项目 1（Kaufman）旨在克服 FVIII 蛋白错误折叠和细胞毒性。 项目 2（Xiao）将揭示导致亚基因组 AAV 载体颗粒形成的机制， 在载体生产过程中通过核酸酶和重组活动形成。项目 3 (Herzog) 将定义 AAV-FVIII 基因转移的先天和适应性免疫反应机制。三者的目标 项目将得到管理核心（核心 A）的支持，该核心为体外提供人类肝细胞 和体内研究（核心 B），以及执行 AAV 载体开发和分子分析的核心（核心 C）。总体而言，该项目运用个别研究人员的专业知识来解决主要问题 FVIII 生物学、血友病基因治疗、肝脏定向基因转移和分子生物学中尚未解答的问题 和 AAV 载体的免疫生物学。