Synthetic Scavenger Medical Countermeasures for Fentanyl

项目摘要/摘要 阿片类药物滥用在美国已经成为一种日益严重的流行病，每年导致数万人过量死亡 去年，特别是因为芬太尼相关的阿片类药物。芬太尼是一种合成阿片类药物，在 不同部位的μ-阿片受体，据估计比吗啡的效力高100倍。这导致了 有效的合成阿片类药物分类为可用作药物的药物 潜在的攻击性化学武器，表明迫切需要有效的医学对策(MCM)。 纳洛酮是一种非选择性竞争性阿片受体拮抗剂，用于逆转 阿片类药物过量或中毒。它是非常有效的，但也有几个缺点。例如，它有低 对像芬太尼这样的强效阿片类药物有效，可能需要多次剂量才能避免再矿化，但可能会 导致阿片类药物戒断综合症。对于暴露后的两种情况，生物清洁剂都是一种有吸引力的MCM策略 对有机磷神经毒剂等有毒物质的治疗和预防。最近，单克隆 抗体(单抗)在小鼠中被证明是芬太尼和卡芬太尼的生物清除剂，并能减少血液中的阿片类药物 浓度。然而，由于需要化学计量生物清除剂来中和芬太尼分子， 由于单抗很大(~150 kDa)，保护或治疗阿片类药物所需的单抗剂量 毒性很大，很难管理。因此，迫切需要一种新的可用于 与纳洛酮等受体拮抗剂联合使用，以克服目前治疗的局限性。 这一探索性研究计划旨在开发用于治疗阿片类药物过量的芬太尼的合成清除剂和 利用SRI专有的光纤阵列筛选技术(FAST)和类蛋白质逆转毒性 合成分子(Techneins)。我们开发了这个平台，使设计、合成、筛选和 大型组合“一珠一化合物”技术文库的测序。FAST支持筛查 针对复杂生物基质中的多个靶点生成具有特定生物特性的先导化合物 功能性和高选择性。这种方法已经被验证为一种药物发现工具，用于抑制 蛋白质-蛋白质相互作用和小分子结合剂。在初步研究中，当一小部分 文库针对芬太尼进行筛选，鉴定出几个Technein匹配并确认与其结合。他们的 相对较小的尺寸(4-6 kDa)，高稳定性，缺乏免疫原性和良好的终端半衰期(~22小时)， 使Techneins成为阿片类药物清道夫的理想候选者。 在这里，我们的目标是开发芬太尼的合成清道夫技术，并测试和优化它们的阻断能力 芬太尼在功能细胞分析中的活性(目标1)，并提供基础PK和临床前疗效数据 顶级抗芬太尼铅(目标2)。这些研究将为开发有效的MCM开辟新的途径 对抗芬太尼和相关的合成阿片类药物，并为应对其他类型的有毒物质铺平道路 探员们。此外，该项目还可能进一步展示一个创新的新药发现平台的效用。

PROJECT SUMMARY/ABSTRACT Opioid abuse has become a growing epidemic in the US, causing tens of thousands of overdose deaths every year especially because of fentanyl-related opioids. Fentanyl is a synthetic opioid that acts as an agonist on the μ-opioid receptors at various sites and is estimated to be 100 times more potent than morphine. This has led to the classification of potent synthetic opioids as Pharmaceutical Based Agents (PBAs) that could be used as a potential offensive chemical weapon, indicating the critical need for effective medical countermeasures (MCMs). Naloxone is a non-selective competitive opioid receptor antagonist that is given to reverse the symptoms of opioid overdose or toxicity. It is highly effective, but also has several disadvantages. For example, it has low efficacy against potent opioids like fentanyl and can require multiple doses to avoid renarcotization, but may then precipitate opioid-withdrawal syndrome. Bioscavengers are an attractive MCM strategy for both post-exposure therapy and prophylaxis against toxic agents such as organophosphate nerve agents. Recently, monoclonal antibodies (mAbs) were shown in mice to be fentanyl and carfentanil bioscavengers, and to reduce blood opioid concentrations. However, since a stoichiometric bioscavenger is needed to neutralize the fentanyl molecules, and since mAbs are large (~150 kDa), the dose of the mAbs required for protection from or treatment of opioid toxicity is large and difficult to administer. Therefore, an urgent need exists for new MCMs that can be used in conjunction with receptor antagonists like naloxone to overcome the limitations of current treatments. This exploratory research program seeks to develop synthetic scavengers for fentanyl for opioid overdose and toxicity reversal utilizing SRI’s proprietary Fiber-optic Array Screening Technology (FAST) and protein-like synthetic molecules (Techneins). We developed this platform to enable the design, synthesis, screening and sequencing of large combinatorial “one-bead one-compound” Technein libraries. FAST enables screening against multiple targets in complex biological matrices to yield lead compounds with specific biological functionality and high selectivity. This approach has been validated as a drug discovery tool for inhibitors of protein-protein interactions and for small molecule binders. In preliminary studies, when a small portion of a library was screened against fentanyl, several Technein hits were identified and confirmed to bind. Their relatively small size (4-6 kDa), high stability, lack of immunogenicity and a good terminal half-life (~22 hours), make Techneins ideal candidates as opioid scavengers. Here we aim to develop synthetic scavenger Techneins for fentanyl and test and optimize their ability to block fentanyl activity in functional cellular assays (Aim 1) and provide basic PK and pre-clinical efficacy data for the top anti-fentanyl lead (Aim 2). These studies will enable new avenues for the development of efficacious MCMs against fentanyl and related synthetic opioids, as well as paving the way for coping with other types of toxic agents. Moreover, the project may further demonstrate utility of an innovative new drug discovery platform.