Development of selective calpain-1 inhibitors for chronic pain

项目总结 在美国历史上，开发新型非阿片类药物的医学需求从未得到满足 慢性疼痛的治疗比今天更紧迫。超过6500万美国成年人患有 慢性疼痛，导致每年近6350亿美元的医疗成本。尽管它们的效果有限，而且 阿片类药物有可能上瘾、耐受和运动能力受损，已成为 慢性疼痛管理，导致阿片类药物流行，肆虐美国各地的社区。 因此，迫切需要开发新的、非阿片类药物来治疗慢性疼痛。这 应用程序通过利用我们的新型人工智能(AI)驱动解决了这一未得到满足的医疗需求 药物发现平台开发Calain-1的选择性抑制剂作为治疗癌症的新型非阿片类药物 慢性疼痛。对慢性神经病理性疼痛动物模型的研究表明，神经损伤会过度激活 Calain-1下调K+Cl-协同转运体活性，导致突触抑制减弱 和神经病理性疼痛。我们小组之前的工作也表明，药物抑制和 全身基因敲除calain-1减轻镰状细胞模型小鼠的慢性疼痛行为 疾病(SCD)。重要的是，抑制Calain-1的镇痛作用不会引起耐受性副作用， 这表明钙蛋白酶-1抑制剂有可能不会使人上瘾。通过应用我们创新的人工 智能(AI)驱动的药物发现平台筛选虚拟化学文库，我们确定了四(4) 新型钙蛋白酶-1抑制剂，并在生化分析中验证了它们的有效性。在此，我们建议 将我们最有效的HIT化合物进展为前导化合物，即Calain-1选择性半胱氨酸蛋白酶 家族选择性、非阿片类药物和中枢神经系统渗透剂，至少对三分之一的慢性疼痛有效 测试的动物模型包括慢性镰状细胞病痛、慢性炎症性疼痛和慢性 神经性疼痛。提出了三个目标，包括目标1：合成~100个我们最有效的类似物 HIT化合物，并对其体外活性和选择性进行表征。成功标准：前20名细胞渗透性， Calain-1抑制剂，对Calain-2有中等选择性，对组织蛋白和 Caspase-1，目标2：评估来自目标1的前20名Calain-1抑制剂的ADME-Tox和PK谱。 成功标准：排名前两位的中枢神经系统穿透性选择性Calain-1抑制剂，体内PK谱良好，以及 目的3：确定我们的顶级Calain-1抑制剂对3种慢性疼痛的疗效及其与PK/PD的关系 动物模型。成功：至少1例慢性痛觉过敏患者的机械性痛觉过敏至少减少40% 疼痛动物模型测试。这一阶段的成功完成将产生一种新型的CNS渗透剂，选择性 在至少1个慢性疼痛动物模型中证明了Calain-1抑制剂的有效性。我们的整体产品 将是第一个口服、中枢神经系统作用的选择性Calain-1抑制剂，用于治疗慢性疼痛。重要的是，我们的产品 将减少慢性疼痛患者的阿片类药物使用，并有助于遏制美国阿片类药物的流行。

PROJECT SUMMARY Never in the history of the United States has the unmet medical need to develop novel, non-opioid therapeutics for chronic pain been more urgent than it is today. More than 65 million US adults suffer from chronic pain, resulting in almost $635 billion in annual healthcare costs. Despite their limited efficacy, and potential for addiction, tolerance, and impaired motor performance, opioids have become a mainstay for chronic pain management, resulting in an opioid epidemic that is ravaging communities throughout the US. Thus, there is an urgent need to develop novel, non-opioid therapies for chronic pain management. This application addresses this unmet medical need by leveraging our novel artificial intelligence (AI)-driven drug discovery platform to develop selective inhibitors of calpain-1 as novel non-opioid therapeutics for chronic pain. Studies in chronic neuropathic pain animal models have shown that nerve injury overactivates calpain-1, which downregulates K+ Cl- cotransporter activity, resulting in diminished synaptic inhibition and neuropathic pain. Prior work by our group has also shown that both pharmacological inhibition and whole body genetic knockout of calpain-1 attenuates chronic pain behaviors in mouse models of sickle cell disease (SCD). Importantly, the analgesic effect of calpain-1 inhibition did not induce tolerance side effects, suggesting the potential for calpain-1 inhibitors to be non-addictive. By applying our innovative artificial intelligence (AI)-driven drug discovery platform to screen a virtual chemical library, we identified four (4) novel calpain-1 inhibitors, and validated them for efficacy in biochemical assays. Here, we propose to progress our most potent hit compound to a lead compound that is calpain-1 selective, cysteine protease family selective, non-opioid, and CNS penetrant with efficacy demonstrated in at least 1 of 3 chronic pain animal models tested, including chronic sickle cell disease pain, chronic inflammatory pain, and chronic neuropathic pain. Three aims are proposed, including Aim 1: Synthesize ~100 analogs of our most potent hit compound, and characterize in vitro activity and selectivity. Success criteria: Top 20 cell-permeable, calpain-1 inhibitors, moderately selective against calpain-2, and highly selective against cathepsins and caspase-1, Aim 2: Evaluate ADME-Tox and PK profile of our top 20 calpain-1 inhibitors from Aim 1. Success criteria: Top 2 CNS-penetrant selective calpain-1 inhibitors with favorable in vivo PK profile, and Aim 3: Determine the efficacy and PK/PD relationship of our top calpain-1 inhibitor in 3 chronic pain animal models. Success: at least 40% reduction in mechanical hyperalgesia in at least 1 of the 3 chronic pain animal models tested. Successful completion of this Phase I will yield a novel CNS-penetrant, selective calpain-1inhibitor with efficacy demonstrated in at least 1 chronic pain animal model. Our overall product would be the first, oral, CNS acting, selective calpain-1 inhibitor for chronic pain. Importantly, our product would reduce opioid usage in chronic pain patients, and help to stem the US opioid epidemic.