Rational design of AAV vectors with human hepatocyte tropism and neutralizing antibody evasion

具有人肝细胞趋向性和中和抗体逃避性的AAV载体的合理设计

• 批准号: 10546241
• 负责人: Chengwen Li
• 金额: $ 26.11万
• 依托单位: BEDROCK THERAPEUTICS, INC.
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10546241
• 关键词: Affect; Albumins; American; Anatomy; Animal Model; Animals; Binding; Biology; Blindness; Blood Component Removal; Canis familiaris; Capsid; Cells; Clinic; Clinical; Clinical Research; Clinical Trials; Data; Dependovirus; Directed Molecular Evolution; Disease; Dose; Engineering; FDA approved; Flow Cytometry; Gene Delivery; Gene Transduction Agent; Gene Transfer; Genetic Diseases; Goals; Hepatocyte; High Prevalence; Human; Immunize; Immunohistochemistry; In Vitro; Industry; Infection; Intravenous Immunoglobulins; Investigation; Libraries; Liver; Liver diseases; Masks; Mediating; Mendelian disorder; Mental Depression; Methods; Mus; Muscular Atrophy; Mutation; Organ; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacologic Substance; Phase; Plasma; Play; Population; Preparation; Prevalence; Price; Primates; Production; Property; Quality of life; Rare Diseases; Research Personnel; Role; Safety; Serotyping; Serum; Spinal; Surface; System; Technology; Therapeutic; Time; Tissues; Traction; Tropism; Variant; Virion; Xenograft Model; Xenograft procedure; adeno-associated viral vector; base; clinical development; cost; cross reactivity; delivery vehicle; efficacy testing; experimental study; gene therapy; humanized mouse; mortality; mutant; neutralizing antibody; novel; phase 2 study; rational design; success; therapeutic transgene; vector; virtual

Adeno-associated virus (AAV) vectors have been successfully applied in clinical trials in patients with diverse disorders. Two AAV based gene therapy drugs have been recently approved by the FDA. Luxturna has been valued at $850,000 for a one-time treatment for a rare form of blindness and Zolgensma priced at $2,100,000 for spinal muscle atrophy. As such, AAV vector based gene therapy is an increasingly attractive market. Although successful in clinical studies, two concerns restrict broader AAV vector applications for patients requiring liver targeted AAV gene therapy following systemic administration: low human hepatocyte transduction and neutralizing antibody (Nab)-mediated inhibition of AAV transduction. Several approaches have been explored for AAV transduction enhancement or capsid Nab evasion. Engineering of the AAV capsid presents a very powerful and popular technology that has been extensively studied to develop novel AAV vectors for enhanced transduction in animal models or Nab escape in vitro. However, it has been demonstrated that the results from mouse experiments do not recapitulate those of large animals such as primates and dogs. Thus, the data for AAV variants generated in animal cells and organs may not translate into successful human applications. Recently, a mouse xenograft model with human hepatocytes has been used to develop human liver targeted AAV vectors for gene therapy. In our previous studies, we have successfully isolated several AAV mutants from the liver of chimeric mice with human hepatocyte xenografts in the presence of human Nabs (IVIG) using the AAV shuffled capsid library approach. Specifically, BDRK001 (AAV mutant LP2-10) demonstrated a much higher ability to evade Nabs than any other AAV serotypes or mutants. However, BDRK001 was not enhanced for transduction in human hepatocytes when compared to the best natural serotype. In this application, we will use rational design strategy to generate novel AAV capsids by variable region I (VRI) domain swapping of BDRK001 using natural serotypes or mutants with high human liver tropism. This panel will then be evaluated in chimeric mice for human hepatocyte transduction (Aim 1) and Nab evasion (Aim 2). Bedrock's long-term goal of this approach is low dose AAV gene therapy for the successful treatment of a variety of liver diseases, independent of the patient's Nab prevalence.

腺相关病毒（AAV）载体已成功应用于各种疾病患者的临床试验， 紊乱两种基于腺相关病毒的基因治疗药物最近获得FDA批准。Luxturna一直是 价值85万美元的一次性治疗一种罕见形式的失明和Zolgensma售价210万美元 治疗脊髓性肌肉萎缩因此，基于AAV载体的基因治疗是一个越来越有吸引力的市场。 尽管在临床研究中取得了成功，但两个问题限制了AAV载体在患者中的更广泛应用 全身给药后需要肝靶向AAV基因治疗：低人肝细胞 转导和中和抗体（Nab）介导的AAV转导抑制。几种方法 已经探索了AAV转导增强或衣壳Nab逃避。AAV工程 衣壳是一种非常强大和流行的技术，已经广泛研究以开发新的 用于在动物模型中增强转导或体外Nab逃逸的AAV载体。然而已经 表明小鼠实验的结果并不能概括大型动物的结果， 灵长类动物和狗。因此，在动物细胞和器官中产生的AAV变体的数据可能无法翻译。 成功地应用于人类。最近，已经建立了具有人肝细胞的小鼠异种移植物模型。 用于开发用于基因治疗的人肝靶向AAV载体。在我们以前的研究中，我们有 成功地从具有人肝细胞异种移植物的嵌合小鼠的肝脏中分离了几种AAV突变体， 使用AAV改组衣壳文库方法检测人Nab（IVIG）的存在。具体而言，BDRK 001 (AAV突变体LP 2 -10）表现出比任何其它AAV血清型高得多的逃避Nab的能力，或 变种人然而，与BDRK 001相比，BDRK 001在人肝细胞中的转导没有增强。 最佳天然血清型。在本申请中，我们将使用合理的设计策略来产生新的AAV衣壳， 使用天然血清型或突变体进行的BDRK 001可变区I（VRI）结构域交换， 向性然后将在嵌合小鼠中评价该组的人肝细胞转导（Aim 1）， Nab回避（目标2）。基岩的长期目标，这种方法是低剂量的AAV基因治疗， 成功治疗各种肝病，与患者的Nab患病率无关。