Discovery of Novel Blood-Brain Barrier Targeting Antibodies for the Treatment of Alzheimer's Disease

摘要 超过500万美国人患有阿尔茨海默氏症(AD)。已批准的仅适用于AD的治疗方法 治疗症状，而不是解决潜在的神经变性。重要的是，修改疾病 延缓AD发病或进展的治疗(DMT)可以减少高达50%的AD病例。然而， 开发治疗AD的DMT的主要障碍是基本上不通透的血脑屏障(BBB)。98%的人 全身注射的疗法和几乎所有的抗体都无法到达大脑，因此无效。 治疗阿尔茨海默病。BBB转运体的成员先前已被用于输送纳米颗粒制剂， 但与重大的科学复杂性和毒性风险有关。Abilita Bio将通过以下方式规避这些风险 利用其专有和创新的平台-Enabled膜蛋白TM(EMP)-开发单个域 抗体(SdAbbs)将与转运蛋白结合，而不改变其自然功能，通过以下途径进入BBB 内吞作用，然后通过胞吐作用进入大脑。然而，转运蛋白的表达水平及其效率 差异很大。因此，Abilita Bio将采取多目标的方式来确定强有力的候选人。我们有 确定4个不同功能亚家族的转运蛋白作为传递AD的新抗体靶点 通过血脑屏障治疗。 此第一阶段SBIR提案的目标是开发我们已确定的4个目标的sdAbb，并执行 血脑屏障体外转运的概念。这将通过执行3个目标来实现。在目标1中，我们将 使用我们的EMP平台进化4个目标，以生成具有增强属性的变体，同时保持 通配类型函数。在目标2中，我们将用我们的EMP变体免疫大羊驼，以开发针对每个目标的sdAbb。 我们将测试sdAbHit的特异性和亲和力。用我们的两首热门歌曲，我们将进行体外概念验证 使用基于微流体的血脑屏障模型进行研究。这种模型比简单的Transwell模型更复杂。 并将提供更多相关数据，以支持未来的体内研究。圆满完成这一阶段 I计划将开发两个潜在的具有体外疗效的候选药物。这一数据将告知体内的疗效和 第二阶段计划中的安全性研究，我们将结合我们的新型BBB转运体sdAb和Abilita Bio的 目前正在接受调查的广告治疗性广告。最终，这种BBB运输机的开发具有 有可能改善AD患者的预后。

SUMMARY Over 5 million Americans suffer from Alzheimer’s Disease (AD). The approved therapies available for AD only treat symptoms and do not address the underlying neurodegeneration. Importantly, disease-modifying therapeutics (DMT) to delay onset or progression of AD could reduce up to 50% of AD cases. However, the major hurdle to developing DMTs for AD is the largely impermeable blood brain barrier (BBB). 98% of all systemically administered therapeutics and virtually all antibodies fail to reach the brain, and thus are ineffective at treating AD. Members of BBB transporters have been previously used to transport nanoparticle formulations, but are associated with significant scientific complexity and toxicity risk. Abilita Bio will circumvent these risks by using its proprietary and innovative platform, Enabled Membrane ProteinTM (EMP), to develop single domain antibodies (sdAbs) that will latch onto transporters without altering their natural function, enter the BBB via endocytosis, then into the brain via exocytosis. However, expression level of transporters and their efficiency widely vary. Therefore, Abilita Bio will take a multi-target approach to identify a strong candidate. We have identified transporters from 4 different functional subfamilies to test as novel antibody targets to deliver AD therapeutics through the BBB. The goal of this Phase I SBIR proposal is to develop sdAbs of our 4 identified targets and perform proof-of- concept of BBB transport in vitro. This will be accomplished through the execution of 3 aims. In Aim 1, we will use our EMP platform to evolve the 4 targets to generate variants with enhanced properties while maintaining wildtype function. In Aim 2, we will immunize llamas with our EMP variants to develop sdAbs against each target. We will test sdAb hits for specificity and affinity. With our two top hits, we will perform in vitro proof of concept studies using a microfluidic-based BBB model. This model provides more complexity than simple transwell systems and will provide more relevant data to support future in vivo studies. Successful completion of this Phase I program will develop potentially two candidates with in vitro efficacy. This data will inform in vivo efficacy and safety studies in a Phase II program where we will combine our novel BBB transporter sdAb with Abilita Bio’s AD therapeutic that is currently under investigation. Ultimately, the development of this BBB transporter has the potential to improve AD patient outcomes.