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: 10722847
• 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/10722847
• 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; 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; Peptide Hydrolases; 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; Tail; Technology; Therapeutic; Thrombosis; Toxic effect; Unstable angina; Venous Thrombosis; Warfarin; analog; cost; design; drug development; drug metabolism; drug standard; enzyme activity; experience; improved; in vivo; inhibitor; interest; manufacture; novel; pharmacokinetics and pharmacodynamics; preclinical development; preclinical study; 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如心脏病发作和中风的主要药物， 也可用于其他疾病，如癌症和COVID-19。虽然几种抗凝剂 包括肝素、华法林和直接口服抗凝剂（DOAC）在临床中使用，每种药剂都遭受 严重和轻微的出血不良反应。到目前为止，一种安全的抗凝剂，抑制凝血， 出血风险尚未出现。根据NHLBI的R 01机制，我们早先发现， 人凝血因子XIa（hFXIa）的肝素结合外位点2与其他同源凝血明显不同 蛋白酶（例如，hFIIa、hFXa和其他）。我们开发了一种新的设计策略， 和芳环，以实现hFXIa的外位点2的高度选择性识别，从而抑制酶 活动我们开发了一种非常有前途的变构抑制剂，命名为硫酸化D-手性肌醇（SCI）， 在四个步骤中合成，对hFXIa显示>100倍的选择性;在外位点2中结合血浆FXIa， 20-60 nM的亲和力，即使当酶的活性位点被共价阻断;并抑制体内动脉 和静脉血栓形成，每只动物250 µg（约1 mg/kg），不增加尾部出血。SCI是 在高达25 mg/大鼠的剂量下耐受，表明治疗窗为~100。SCI是一个非常有前途的 抗凝血剂;但其药代动力学不是最好的。利用肝素类药物的线索，我们假设 优化D-手性肌醇支架上硫酸酯基团的数量和位置，同时筛选 其各种立体异构体将改善hFXIa亲和力、抑制效力、PK、药效学（PD）， 化学、制造和控制（CMC）特性，然后再开始IND使能研究。当前 一项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药物。具体目标是：1）综合， 基于SCI结构的20种推定因子XIa抑制剂的抗凝效力和出血; 2）体内 抑制剂的抗血栓功效、DMPK、体外和体内毒性;和3）扩大非GMP合成， 用于识别一种或两种先导分子的CMC、剂量递增疗效和PD研究。SCI已在 美国专利（#9，758，459 B2，标题为“作为抗凝剂的因子XIa的变构调节剂”），PI为 发明者之一。关于合成、体外和体内功效、体外和体内 体内毒性将用于指导从R61阶段到R33阶段的过渡。或者，最好的1（或2）类似物 的SCI将被确定为最有前途的代理人，以进一步的IND使研究从20 设计SCI类似物。