IND Enabling Studies for Small Molecule Anthrax Lethal Factor Inhibitors

描述（由申请人提供）：PanThera拟议研究的目标是确定一种临床候选药物，该候选药物在暴露后吸入性炭疽动物模型中具有体内疗效，并且具有适合用于人类作为炭疽致死因子中毒解毒剂的安全性。2001年通过美国邮件的炭疽孢子袭击导致11例吸入性炭疽确诊病例。尽管给予一线抗生素和现代重症监护支持，这些患者中只有6人存活。如此高的死亡率，加上广泛的恐慌和巨大的清理成本，清楚地说明了这一生物恐怖事件的严重性，以及炭疽对国家安全构成的极端威胁。目前可用于治疗炭疽的治疗方法，如抗生素和免疫治疗剂（疫苗和单克隆抗体），在动物模型中暴露前施用时显示出完全的保护作用。然而，随着暴露后治疗延迟时间的增加，它们的保护能力急剧下降，这表明毒血症仍然是对宿主生存的威胁。炭疽病的复杂发病机制包括细菌和毒素成分，尽管抗生素可以清除系统中的细菌并关闭毒素的来源，生物制剂可以阻止毒素进入细胞，但目前还没有治疗方法可以解除已经存在于细胞中的毒素。PanThera已经鉴定出具有皮摩尔效力的新型炭疽致死因子抑制剂（LFIs），并在大鼠、小鼠和兔炭疽模型中证明了体内疗效。与仅作用于细胞外的生物制剂相比，这些lfi旨在通过作用于细胞内和细胞外来减轻早期和晚期毒血症。小分子lfi还可以作为对抗耐药的炭疽芽孢杆菌菌株（增强剂）和用于传递细胞内炭疽LF毒素的新型病毒载体（高级剂）的对策。该项目的具体目标是：1)完成先导优化研究并选择临床前候选药物；2)开展足以与FDA进行ind前会议的早期ind支持研究；3)完成向FDA提交IND所需的剩余IND研究。为了实现这些目标，我们组建了一个科学家团队，他们是细菌毒素和炭疽疾病领域的领导者。这个专家合作团队为我们提供了独特的动物模型：大鼠毒素和小鼠炭疽孢子攻击模型（Leppla实验室；NIH），以及兔吸入炭疽孢子攻击模型（Peterson实验室；UTMB）。

DESCRIPTION (provided by applicant): PanThera's goal for the proposed research is to identify a clinical candidate that demonstrates in vivo efficacy in animal models of post-exposure inhalation anthrax and has a safety profile suitable for use in humans as an antidote to anthrax lethal factor intoxication. The 2001 anthrax spore attack via the U.S. mail caused 11 confirmed cases of inhalation anthrax. Despite the administration of frontline antibiotics and modern day intensive care support, only six of these patients survived. This high mortality rate, along with the widespread panic and considerable cleanup cost, starkly defined the seriousness of this bioterrorist event and the extreme threat anthrax poses to national security. Therapeutics currently available to treat anthrax, such as antibiotics and immunotherapeutic agents (vaccines and monoclonal antibodies), show complete protection in animal models when administered pre-exposure. However, their protective capability diminishes dramatically as post-exposure treatment delay times increase, suggesting that toxemia remains a threat to host survival. The complex pathogenesis of anthrax disease includes both bacterial and toxin components, although antibiotics can clear the system of bacteria and shut off the source of the toxins, and biological agents can block the transport of toxins into the cells, no therapeutic is currently available to disarm the toxins already present in the cells. PanThera has identified novel anthrax lethal factor inhibitors (LFIs) with picomolar potency and demonstrated in vivo efficacy in rat, mouse, and rabbit models of anthrax. These LFIs are designed to mitigate both early and late-stage toxemia by acting intracellularly and extracellularly, in contrast to biologics which ac only extracellularly. Small molecule LFIs should also provide a countermeasure against antibiotic resistant strains of B. anthracis (Enhanced Agents) and against novel viral vectors engineered to deliver intracellular anthrax LF toxin (Advanced Agents). The specific aims of the proposed project are: 1) complete lead optimization studies and select a preclinical candidate; 2) conduct early IND-enabling studies sufficient for a pre-IND meeting with the FDA; and 3) complete the remaining IND studies needed for submission of an IND to the FDA. To achieve these aims we have assembled a team of scientists who are leaders in the field of bacterial toxins and anthrax disease. This team of expert collaborators provides us with unique animal models: rat toxin and mouse spore challenge models of anthrax (Leppla lab; NIH), as well as a rabbit inhalation spore challenge model of anthrax infection (Peterson lab; UTMB).