MICA: Single-domain antibody oligonucleotides conjugates for brain delivery of oligonucleotide therapeutics

MICA：单域抗体寡核苷酸缀合物，用于脑部递送寡核苷酸治疗剂

• 批准号: MR/X004686/1
• 负责人: Francois Halloy
• 金额: $ 64.75万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FX004686%2F1
• 关键词: MICA; Single; domain; antibody; oligonucleotides

Therapeutic oligonucleotides (ONs) are synthetic ribonucleic acid (RNA)-like sequences which constitute a major class of novel therapeutics for human disease. ONs recognize and bind a cognate RNA target of complementary sequence in the cell and thereby trigger a range of cellular responses, from RNA degradation to altered maturation of the RNA target. ONs are of high interest for the treatment of genetic diseases, where mutations may alter stability and maturation of protein coding RNAs which can be corrected by ON therapy. 15 ONs have been approved by regulatory authorities so far, and many more are being evaluated in clinical trials.A major translational bottleneck in ON drug development is achieving effective in vivo delivery to relevant tissues and cell types. Upon systemic injection, e.g. subcutaneous or intravenous, ONs distribute rapidly through the bloodstream but do not readily cross biological barriers like the blood-brain barrier (BBB). Achieving delivery beyond the BBB is of prime relevance for the treatment of severe neuromuscular disorders such as spinal muscular atrophy (SMA) or amyotrophic lateral sclerosis (ALS), which cause neuronal degeneration in brain and spinal cord. Brain delivery of ONs might be mediated through intrathecal injection, i.e. directly into the spinal cord. This mode of injection is however riskier and unpractical for repeated injections. A prominent strategy to improve the delivery ONs is chemical bridging (conjugation) to a molecule facilitating uptake into the right tissue and cell type. Over the years, multiple conjugate moieties have been developed. Cell-penetrating peptides, small-molecule ligands, and antibodies facilitate the intracellular uptake of ON drugs. A very succesful example is the GalNac (N-Acetylgalactosamine) ligand, which increases delivery to hepatocytes of the liver by a factor 10. The first GalNac-ON conjugate, givosiran, was approved for the treatment of acute hepatic porphyria in 2019. A first antibody-oligonucleotide conjugate also entered clinical trials in 2021 for increased delivery to muscle tissue in the context of myotonic dystrophy type I (DM1). A recent development from the antibody field are single-domain antibodies, as known as "VHHs" or nanobodies. Nanobodies are about 10 times smaller in molecular weight than conventional antibodies but retain full biological activity. They are easier to produce and modify chemically. However, little is known about their potential for delivery of oligonucleotide payloads into tissues. This proposal aims to advance nanobody-oligonucleotides as delivery vehicles for brain delivery and as therapeutics for SMA. The proposal is broken down into four aims:1- Develop oligonucleotide-nanobody conjugation chemistries. We will evaluate nanobodies targeting the transferrin receptor 1 (TfR1) and conjugated to several ON chemistries through cleavable or non-cleavable linkers. Biological activity and uptake will be assayed. Cleavable linkers have been used for large conjugates to release therapeutic payloads within target cells, but this may be less critical for nanobodies.2- Develop novel nanobodies for delivery beyond biological barriers. Many receptors other than TfR1 could be harnessed for delivery beyond the BBB. We will develop nanobodies for four receptors and evaluate their potential for drug delivery into the brain.3- Establish pharmacokinetics properties of oligonucleotide-nanobody conjugates, as compared to large antibody oligonucleotide conjugates and unconjugated oligonucleotides.4- Advance oligonucleotide imaging by cutting-edge tandem mass spectrometry, for precise detection and visualization of therapeutic oligonucleotides within cells and tissues.

治疗性寡核苷酸（Ons）是合成的核糖核酸（RNA）样序列，其构成了用于人类疾病的主要类别的新型治疗剂。ON识别并结合细胞中互补序列的同源RNA靶，从而触发一系列细胞反应，从RNA降解到RNA靶的成熟改变。ON对于治疗遗传性疾病具有高度意义，其中突变可以改变蛋白质编码RNA的稳定性和成熟，这可以通过ON疗法来校正。目前，已有15种ON类药物被批准上市，更多的ON类药物正在进行临床试验，而实现有效的体内给药是ON类药物开发的一个主要瓶颈。在全身注射后，例如皮下或静脉内，ON通过血流快速分布，但不容易穿过生物屏障，如血脑屏障（BBB）。实现超过BBB的递送对于治疗严重的神经肌肉病症如脊髓性肌萎缩症（SMA）或肌萎缩性侧索硬化症（ALS）具有主要相关性，其引起脑和脊髓中的神经元变性。ON的脑递送可以通过鞘内注射介导，即直接进入脊髓。然而，这种注射模式对于重复注射来说风险更大并且不切实际。改善递送ON的突出策略是化学桥接（缀合）至分子，从而促进摄取到正确的组织和细胞类型中。多年来，已经开发了多种缀合物部分。细胞穿透肽、小分子配体和抗体促进ON药物的细胞内摄取。一个非常成功的例子是GalNac（N-乙酰半乳糖胺）配体，它将向肝细胞的递送增加了10倍。第一个GalNac-ON缀合物givosiran于2019年被批准用于治疗急性肝卟啉症。第一种抗体-寡核苷酸缀合物也于2021年进入临床试验，用于在I型肌强直性营养不良（DM 1）的背景下增加向肌肉组织的递送。抗体领域的最新发展是单结构域抗体，称为“VHH”或纳米抗体。纳米抗体的分子量比常规抗体小约10倍，但保留完整的生物活性。它们更容易生产和化学修饰。然而，很少有人知道他们的潜在交付寡核苷酸有效载荷进入组织。该提案旨在推进纳米抗体-寡核苷酸作为脑递送的递送载体和作为SMA的治疗剂。该提案分为四个目标：1-开发利奈肽-纳米抗体缀合化学。我们将评估靶向转铁蛋白受体1（TfR 1）并通过可切割或不可切割的接头与几种ON化学物质缀合的纳米抗体。将测定生物活性和摄取。可切割的连接体已用于大缀合物以在靶细胞内释放治疗有效载荷，但这对于纳米抗体可能不那么重要。2-开发用于递送超过生物屏障的新型纳米抗体。除了TfR 1之外的许多受体可以被利用来递送到BBB之外。我们将开发四种受体的纳米抗体，并评估其药物输送到大脑中的潜力。3-建立阿托替尼-纳米抗体缀合物的药代动力学特性，与大抗体寡核苷酸缀合物和未缀合的阿托替尼相比。4-先进的寡核苷酸成像通过尖端串联质谱法，用于精确检测和可视化细胞和组织内的治疗性寡核苷酸。