Lead identification and pre-clinical studies on allosteric inhibitors of coagulation factor XIa

凝血因子 XIa 变构抑制剂的先导化合物鉴定和临床前研究

• 批准号: 10369394
• 负责人: Umesh Ramanlal Desai
• 金额: $ 54.34万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10369394
• 关键词: Active Sites; Adverse effects; Affinity; Animals; Anticoagulant therapy; Anticoagulants; Anticoagulation; Area; Binding; Biological; Biotechnology; COVID-19; Chemistry; Clinic; Clinical; Clinical Research; Coagulation Process; Cues; Disease; Dose; Drug Costs; Drug Interactions; Drug Kinetics; Drug usage; Elements; Enoxaparin; Enzyme Inhibition; Enzymes; Factor XIa; Fibrinolytic Agents; Goals; Health Care Costs; Hemorrhage; Heparin; Heparin Binding; Human; In Vitro; Incubators; Inositol; Institution; Lead; Leadership; Legal patent; Libraries; Location; Malignant Neoplasms; Measures; Minor; Myocardial Infarction; Names; National Heart, Lung, and Blood Institute; New Agents; Oral; Outpatients; Pathway interactions; Pharmaceutical Preparations; Pharmacodynamics; Phase; Plasma; Population Characteristics; Positioning Attribute; Preparation; Property; Rattus; Renal clearance function; Research Project Grants; Risk; Role; Self Administration; Stereoisomer; Stroke; Structure; Sulfate; Synthesis Chemistry; Tail; Technology; Therapeutic; Thrombosis; Toxic effect; Triad Acrylic Resin; Unstable angina; Venous Thrombosis; Warfarin; analog; base; design; drug development; drug metabolism; drug standard; enzyme activity; experience; improved; in vivo; inhibitor; interest; novel; pharmacokinetics and pharmacodynamics; preclinical development; preclinical study; protease E; rational design; scaffold; scale up; screening; small molecule; thrombotic

Anticoagulants are the mainstay in the treatment of thrombotic diseases, such as heart attack and stroke, and may also be used in other diseases such as cancer and COVID-19. Although several anticoagulants including heparins, warfarin, and direct oral anticoagulants (DOACs) are used in the clinic, each agent suffers from major and minor bleeding adverse effects. As of now, a safe anticoagulant that inhibits coagulation without bleeding risk has not been developed as yet. Under the NHLBI's R01 mechanism, we earlier discovered that the heparin-binding exosite 2 of human factor XIa (hFXIa) is remarkably different from other homologous coagulation proteases (e.g., hFIIa, hFXa and others). We developed a novel design strategy that relies on anionic sulfates and aromatic rings to effect highly selective recognition of hFXIa's exosite 2 resulting in inhibition of enzyme activity. We developed a highly promising allosteric inhibitor, named sulfated D-chiro-inositol (SCI), which was synthesized in four steps, displayed >100-fold selectivity for hFXIa; bound plasma FXIa in exosite 2 with an affinity of 20–60 nM even when the enzyme's active site was covalently blocked; and inhibited in vivo arterial and venous thrombosis in the rat at 250 µg per animal (~1 mg/kg) without enhancing tail bleeding. SCI was tolerated at doses as high as 25 mg/rat suggesting a therapeutic window of ~100. SCI is a highly promising anticoagulant; yet its pharmacokinetics is not the best. Using cues from heparin-based drugs, we hypothesize that optimizing the number and position of sulfate groups on the D-chiro inositol scaffold, while also screening its various stereoisomers would improve hFXIa affinity, inhibition potency, PK, pharmacodynamics (PD), and chemistry, manufacturing and controls (CMC) properties before embarking on IND-enabling studies. The current proposal focuses on studying a library of 20 rationally designed SCI analogs with the goal of identifying at least one LEAD AGENT for advanced stage pre-clinical development. The specific aims are 1) synthesis, anticoagulation efficacy, and bleeding of 20 putative factor XIa inhibitors based on the SCI structure; 2) in vivo antithrombotic efficacy, DMPK, in vitro and in vivo toxicity of inhibitors; and 3) scaled-up non-GMP synthesis, CMC, dose escalation efficacy, and PD studies to identify one or two lead molecules. SCI has been claimed in a US patent (#9,758,459 B2 titled `Allosteric modulators of factor XIa as anticoagulant agents') with the PI as one of the inventors. Quantitative milestones with regard to synthesis, in vitro & in vivo efficacy, in vitro and in vivo toxicity will be used to guide the transition from the R61 to R33 Phase. Alternatively, the best 1 (or 2) analogs of SCI would be identified as the most promising agent for further IND-enabling studies starting from the 20 designed SCI analogs.

抗凝剂是治疗血栓性疾病的主要药物，如心脏病发作和中风， 也可能用于其他疾病，如癌症和新冠肺炎。尽管有几种抗凝剂 包括肝素、华法林和直接口服抗凝剂(DOAC)在临床上使用，每种药物都受到 减轻大出血和轻微出血的不良反应。到目前为止，一种安全的抗凝血剂可以在没有 出血风险尚未形成。在NHLBI的R01机制下，我们早先发现 人凝血因子Xia的肝素结合Exosite 2(HFXIa)与其他同源凝血系统有显著不同 蛋白水解酶(如hFIIa、hFXa等)。我们开发了一种新的设计策略，依赖于阴离子硫酸盐 和芳环对hFXIa的外显子2进行高选择性识别，从而抑制酶 活动。我们开发了一种很有前途的变构抑制剂，名为硫酸D-环肌醇(SCI)，它是 分四步合成，在Exosite 2中显示了100倍的hFXIa；结合血浆FXIa的选择性 亲和力为20-60 nM，即使当酶的活性部位被共价阻断时也是如此；并抑制体内动脉 大鼠静脉血栓形成，每只动物250微克(~1 mg/kg)，但不增加尾巴出血。SCI曾经是 耐受剂量高达每只大鼠25毫克，提示治疗窗口为~100。SCI是一个很有前途的 抗凝剂；但其药代动力学并不是最好的。根据肝素类药物的线索，我们假设 优化了D-chiro肌醇支架上硫酸盐基团的数目和位置，同时也进行了筛选 它的各种立体异构体将提高hFXIa亲和力、抑制效力、PK、药效学(PD)和 化学、制造和控制(CMC)属性，然后开始支持IND的研究。海流 提案的重点是研究一个由20个合理设计的SCI类似物组成的库，目标是至少识别出 一种用于晚期临床前开发的先导剂。具体目标是1)合成， 基于脊髓损伤结构的20种可能的XIA因子抑制剂的抗凝和出血作用；2)体内 抑制剂的抗血栓疗效、DMPK、体外和体内毒性；以及3)放大的非GMP合成， CMC、剂量递增效应和PD研究以确定一个或两个铅分子。脊髓损伤已在 一项美国专利(#9,758,459 B2，标题为‘作为抗凝剂的XIA因子的变构调节剂’)，其PI AS 发明者之一。关于合成、体外和体内疗效、体外和体内疗效的定量里程碑 体内毒性将被用来指导从R61到R33阶段的过渡。或者，最好的1(或2)类比 将被确定为最有希望的药物，从20%开始进行进一步的IND研究 设计了SCI类比。