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（ON）是合成的核糖核酸（RNA）样序列，构成人类疾病的一类主要新型疗法。 ONs 识别并结合细胞中互补序列的同源 RNA 靶标，从而触发一系列细胞反应，从 RNA 降解到 RNA 靶标成熟的改变。 ON 对遗传疾病的治疗具有很高的意义，其中突变可能会改变蛋白质编码 RNA 的稳定性和成熟度，而这些可以通过 ON 治疗来纠正。迄今为止，已有 15 个 ON 获得监管机构的批准，还有更多 ON 正在临床试验中进行评估。ON 药物开发的一个主要转化瓶颈是实现向相关组织和细胞类型的有效体内递送。全身注射后，例如皮下或静脉内，ONs通过血流快速分布，但不容易穿过血脑屏障（BBB）等生物屏障。实现 BBB 之外的递送对于治疗严重的神经肌肉疾病至关重要，例如脊髓性肌萎缩症 (SMA) 或肌萎缩侧索硬化症 (ALS)，这些疾病会导致大脑和脊髓神经元变性。 ONs 的脑递送可能通过鞘内注射介导，即直接注射到脊髓中。然而，这种注射方式对于重复注射来说风险更大且不切实际。改善 ON 递送的一个重要策略是与分子进行化学桥接（缀合），以促进正确的组织和细胞类型的吸收。多年来，已经开发了多个缀合物部分。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，它将向肝脏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。第一个抗体-寡核苷酸缀合物也于 2021 年进入临床试验，以增加递送 I 型强直性肌营养不良 (DM1) 背景下的肌肉组织。抗体领域的最新发展是单域抗体，称为“VHH”或纳米抗体。纳米抗体的分子量比传统抗体小约 10 倍，但保留了完整的生物活性。它们更容易通过化学方法生产和修饰。然而，人们对它们将寡核苷酸有效负载递送到组织中的潜力知之甚少。该提案旨在推动纳米抗体寡核苷酸作为大脑递送的递送载体和 SMA 的治疗药物。该提案分为四个目标：1-开发寡核苷酸-纳米抗体缀合化学。我们将评估靶向转铁蛋白受体 1 (TfR1) 并通过可裂解或不可裂解接头与多种 ON 化学物质缀合的纳米抗体。将测定生物活性和摄取。可切割的接头已用于大型缀合物，以在靶细胞内释放治疗有效负载，但这对于纳米抗体来说可能不太重要。2-开发新型纳米抗体，用于超越生物屏障的递送。除 TfR1 之外的许多受体都可以用于 BBB 之外的传递。我们将为四种受体开发纳米抗体，并评估它们将药物输送到大脑的潜力。3- 与大抗体寡核苷酸缀合物和未缀合的寡核苷酸相比，建立寡核苷酸-纳米抗体缀合物的药代动力学特性。4- 通过尖端串联质谱法推进寡核苷酸成像，以精确检测和可视化 细胞和组织内的治疗性寡核苷酸。