Novel non-narcotic analgesic for acute and chronic pain

摘要 急性和慢性疼痛影响着5000多万美国人，对安全的巨大需求尚未得到满足 止痛药。虽然对乙酰氨基酚(APAP)是最常用的止痛药物之一， 肝脏毒性是一种风险，过量服药是急性暴发性肝功能衰竭最常见的原因。氧化 APAP对N-乙酰-对苯二酚亚胺(NAPQI)具有肝毒性。我们合成了APAP类似物 含有连接到对酰氨基苯酚片段的杂环部分，并与其代谢物类似物 创建以进一步增强安全性(消除肝和肾毒性)，同时保留止痛和 退烧药。液相色谱-串联质谱仪显示小鼠无NAPQI 在NAPQI形成期间，腹腔或口服这些新化学物质的毒性剂量 APAP处理的小鼠的肝脏。线粒体自由基标记物硝基酪氨酸的免疫组织化学染色 在APAP处理的小鼠的肝脏中观察到，但在新化学实体处理的小鼠中没有观察到。此外， 肝紧密连接的完整性，APAP的另一个标志-肝脏毒性，在大剂量的 APAP，但不是在用这些新化学实体处理的小鼠身上。接下来，广泛的概念验证研究使用 不同的体内镇痛试验(von Frey、冷甩尾法和扭腹法)和体内退热模型 (LP-和Baker‘s酵母)使我们找到了一种用于临床前开发的先导化合物，SRP-3D(二乙胺[DA])。 到目前为止，我们已经完成了以下关于SRP-3D(DA)的IND使能研究：1)1公斤的规模合成 CGMP，2)生物分析方法的建立，3)细胞色素P450同工酶图谱的鉴定， 4)证明了先导化合物的稳定性和人体肝细胞中的代谢物，以及5)确认 它没有致突变性(艾姆斯试验)。综上所述，这些支持IND的研究结果支持 遵循这个STTR-Hear快速通道项目的具体目标。具体目标1：论证可行性 用于SRP-3D(DA)的药物开发；具体目标2：确定最有效的口服和静脉注射 用于慢性和急性疼痛适应症的SRPS-3D(DA)的配方；以及具体目标3：进一步 通过完成GLP毒理学来降低IND提交的风险。我们建议的研究还包括 包括在性别和老龄化过程中定义止痛概况。这些目标将是 SRP-3D(DA)商业化，安全治疗急慢性疼痛。鉴于APAP的广泛使用， 过度使用和持续的阿片类药物流行带来的肝毒性风险，这种新的化学实体代表着一种 无肝毒性的新型非麻醉性止痛药。

Abstract Acute and chronic pain affect more than 50 million Americans and there is an enormous unmet need for safer pain relief. Although acetaminophen (ApAP) is among the medicines most commonly used for pain relief, hepatotoxicity is a risk and overdose is the most common cause of acute fulminant hepatic failure. Oxidation of ApAP to N-acetyl-p-benzoquinone imine (NAPQI) leads to hepatotoxicity. We synthesized ApAP analogues bearing a heterocyclic moiety linked to the p-acylaminophenol fragment, and analogs to its metabolite were then created to further enhance the safety profile (eliminating liver and kidney toxicity) while retaining analgesia and antipyresis. Liquid chromatography tandem mass spectrometry demonstrated no NAPQI formation in mice after intraperitoneal or oral administration of toxic doses of these new chemical entities while NAPQI was formed in the liver of ApAP-treated mice. Immunostaining for nitrotyrosine, a mitochondrial free radical marker, was observed in liver from ApAP-treated mice but not in mice treated with the new chemical entities. Moreover, the integrity of hepatic tight junctions, another hallmark of ApAP-hepatotoxicity, was lost in mice after high doses of ApAP, but not in mice treated with these new chemical entities. Next, extensive proof of concept studies using different in vivo analgesia assays (von Frey, cold tail flick and abdominal writhing) and in vivo anti-pyretic models (LPS- and Baker’s yeast) led us to a lead compound for pre-clinical development, SRP-3D (diethylamide [DA]). To date, we have completed the following IND-enabling studies for SRP-3D (DA): 1) scale synthesis of 1kg cGMP, 2) establishment of bioanalytical methods, 3) characterization of the cytochrome P450 isoenzyme profile, 4) demonstration of the lead compound’s stability and metabolites in human hepatocytes, and 5) confirmation that it is not mutagenic (Ames test). Taken together the results of these IND-enabling studies support the following Specific Aims for this STTR-HEAL Fast-Track project. Specific Aim 1: Demonstrate the feasibility for drug development of SRP-3D (DA); Specific Aim 2: Determine the most effective oral and intravenous formulations of SRPs-3D (DA) for both chronic and acute pain indications; and Specific Aim 3: Further de-risk development toward an IND submission by completing GLP-toxicology. Our proposed studies also include defining analgesia profile in gender and during aging. These Aims will be a decisive step in commercialization of SRP-3D (DA) to treat acute and chronic pain safely. Given the widespread use of ApAP, the risk of hepatotoxicity with overuse and the ongoing opioid epidemic, this new chemical entity represents a novel non-narcotic analgesic without hepatotoxicity.