Targeted Identification of Dual Acting Antisickling Agents for Sickle Cell Disease Therapy

我们R61/R33提案的总体目标是设计和研究针对镰状细胞的新型治疗药物 疾病(SCD)抑制和/或破坏最初的缺氧诱导的血红蛋白(Hb)聚合，从而 减少后续的二次病理生理学，对毒性的影响最小。当脱氧时， 镰状Hb聚合成长的、坚硬的、不溶于水的纤维，导致红细胞(RBC)呈镰状。这项建议 利用调查团队的互补专业知识、承诺和经验；以及 令人信服的大量初步数据来测试这样一个假设，即直接破坏稳定的新型合成分子 聚合物的形成，除了增加Hb对O2的亲和力外，还将为SCD提供更好的治疗选择。 具体目标是：1.设计、合成并进行体外功能和生物学评价 新型香兰素衍生物。我们之前已经建立了新的抗呕吐衍生物，显示出显著的 比它们的母体化合物具有更好的药理作用。这一目标进一步利用了错综复杂和消息灵通的 衍生先导化合物的策略，以增加直接聚合物的不稳定，以及减少 与Hb结合的化合物的化学计量。我们将对这些化合物进行一系列筛选化验 评估体外功能和生物学特性，包括Hb修饰，抑制细胞镰状，效果 关于Hb对O2的亲和力，以及X射线结晶学来阐明它们与Hb的原子相互作用。目标1研究将 确定优秀的候选人，并通知进一步的结构修改，以提高后续目标的效力 2对R61期的研究。2：建立Hb结合动力学、体外代谢和ADME，以及 选定化合物的初步体内药效学性质。在R61的这一最终目标中 阶段，我们将对目标1中挑选的候选人进行进一步的验证研究。具体来说，我们将 表征它们在红细胞室中的分配效率和Hb结合动力学，体外代谢 和ADME/安全性概况，以及初步的体内药效学概况。计划中的研究结果 将坚定和决定性地确定和验证优势铅分子(S)在目标3(R33)中的进一步发展 阶段)。3：进行体内功能和生物学研究，以确定有希望的先导化合物 发展。目的3(R33)将集中在野生型和SCD小鼠体内的PK/PD疗效研究。我们会 进行优化的铅分子的放大合成，优化配方，并正式进行详细的研究。 体内PK/PD和疗效研究，包括体内将Hb修饰为非镰状、高亲和力突变体； 常氧和低氧条件下循环镰状细胞减少；溶血、炎症、 内皮损伤；以及在该模型中观察到的SCD病理生理学的整体逆转。这部小说 预计化合物将在减少剂量的情况下表现出更强的疗效。我们将与加速器合作 从我们目前的潜在候选人名单中选出合作伙伴。我们将获得所需的成本匹配资金，以支付 执行此阶段并将领导(S)推进到开发阶段所需的成本。

Our overall objective of this R61/R33 proposal is to design and study novel therapeutic agents for sickle cell disease (SCD) that inhibit and/or destabilize the initial, hypoxia-induced hemoglobin (Hb) polymerization, thereby reducing the subsequent secondary pathophysiology, with minimal liability for toxicity. When deoxygenated, sickle Hb polymerizes into long, rigid, and insoluble fibers, causing red blood cells (RBCs) to sickle. The proposal leverages the complementary expertise, commitment, and experience of the investigative team; and a compelling body of preliminary data to test the hypothesis that novel synthetic molecules that directly destabilize polymer formation, in addition to increasing Hb affinity for O2, will provide a superior therapeutic option for SCD. The specific aims are: 1: Design, synthesize and conduct in-vitro functional and biological assessment of novel vanillin derivatives. We have previously established novel antisickling derivatives that exhibit significant pharmacologic improvement over their parent compounds. This aim further utilizes an intricate and informed strategy to derivatize lead compounds to increase direct polymer destabilization, as well as decrease stoichiometry of compound binding to Hb. We will subject the compounds to a battery of screening assays to evaluate in-vitro functional and biological properties, to include Hb modification, inhibition of cell sickling, effect on Hb affinity for O2, and X-ray crystallography to elucidate their atomic interactions with Hb. Aim 1 studies will identify superior candidates and inform further structural modifications to enhance potency for subsequent Aim 2 studies of the R61 phase. 2: Establish Hb binding kinetics, in-vitro metabolism and ADME, and preliminary in-vivo pharmacodynamics properties of select compounds. In this concluding Aim of the R61 phase, we will conduct further validation studies on select candidates from Aim 1. Specifically, we will characterize their efficiency of partitioning into the RBC compartment and Hb binding kinetics, in-vitro metabolic and ADME/safety profiles, and preliminary in-vivo pharmacodynamic profiles. Results from the planned studies will firmly and conclusively identify and validate superior lead molecule(s) for further development in Aim 3 (R33 Phase). 3: Conduct in-vivo functional and biological studies to establish promising lead compounds for development. Aim 3 (R33) will focus on in-vivo PK/PD efficacy studies in wild-type and SCD mice. We will conduct scale-up synthesis of optimized lead molecules, optimize formulation, and formally conduct detailed in- vivo PK/PD and efficacy studies that include in-vivo modification of Hb to the non-sickling, high affinity variant; reduction in circulating sickled cells under normoxia and hypoxia; amelioration of hemolysis, inflammation, endothelial damage; and overall reversal of the SCD pathophysiology observed in this model. The novel compounds are expected to exhibit enhanced efficacy at reduced doses. We will collaborate with accelerator partners from our current list of potential candidates. We will obtain required cost-matching funds to defray the costs required to execute this phase and advance the lead(s) into the development phase.