Clot-Targeted Antithrombotics for Venous Thromboprophylaxis

用于预防静脉血栓的凝块靶向抗血栓药物

• 批准号: 9795082
• 负责人: Elliot Chaikof
• 金额: $ 42.28万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9795082
• 关键词: Antibodies; Anticoagulants; Antiplatelet Drugs; Automobile Driving; Biological; Blood Platelets; Charge; Clinical; Coagulation Process; Complex; Development; Effectiveness; Event; Fibrin; Fibrinolytic Agents; Fibrosis; Generations; HMGB1 gene; Hemorrhage; Hemostatic Agents; Hospital Mortality; Hospitals; Human; Hybrids; Immune response; In Vitro; Inflammatory Response; Leukocytes; Maintenance; Maps; Molecular Conformation; Morbidity - disease rate; Pathway interactions; Peptides; Peripheral Blood Mononuclear Cell; Platelet Activation; Play; Population; Postphlebitic Syndrome; Process; Production; Property; Proteins; Recombinants; Resolution; Risk; Role; Site; Surface; T-Lymphocyte Epitopes; Therapeutic; Thrombin; Thromboembolism; Thrombosis; Thrombus; Ticks; Transgenic Mice; Urokinase; Variant; Veins; Venous; Venous Thrombosis; base; computerized tools; design; effective therapy; experimental study; immunogenic; immunogenicity; in vivo; lead candidate; mouse model; neutrophil; pharmacokinetics and pharmacodynamics; prevent; response

Project Summary We currently lack effective therapies that reduce the risk of venous thromboembolism without an attendant risk of bleeding. The assembled investigative team has recently identified single chain antibodies that selectively block activated platelets and enrich therapeutics at the site of a developing thrombus. In the process, we have discovered that selective targeting of activated platelets allows a wide variety of antithrombotic agents to be efficacious, well below systemic concentrations that cause bleeding. In this proposal, we postulate that selective targeting to activated platelets provides a means to locally concentrate antiplatelet, anticoagulant, and fibrinolytic agents at the site of a growing venous thrombus without disrupting essential hemostatic processes. We believe that this strategy will enable the design of high potency agents for venous thromboprophylaxis, but without an increased risk of major bleeding. In this proposal, we intend to: (1) Define the ability of clot-targeted “dual pathway” antithrombotics to prevent venous thrombosis and inhibit postthrombotic vein wall fibrosis without hemostatic disturbance. The efficacy of “dual pathway” antithrombotics based on SCE5-TAP, a single chain antibody with both antiplatelet and anticoagulant activity will be defined using murine models of venous thrombosis. These studies will evaluate the capacity of SCE5-TAP and related new variants to prevent venous thrombosis, limit early and late inflammatory responses, and inhibit thrombus-induced remodeling of the vein wall without hemostatic disturbance. (2) Determine the capacity of clot-targeted antithrombotics that display anti-platelet and fibrinolytic activity to inhibit venous thrombosis and postthrombotic vein wall remodeling. The effectiveness of antithrombotics based on SCE5-scuPA, a single chain antibody with both antiplatelet and fibrinolytic activity will be defined using murine models of venous thrombosis alone or in combination with SCE5-TAP or related new variants. We will also design recombinant clot-targeted hybrid constructs (SCE5-TAP-scuPA) that display antiplatelet, anticoagulant, and fibrinolytic activity. The ability of these agents to inhibit thrombosis, promote thrombus resolution, and limit the development of vein wall fibrosis will be defined. (3) Mitigate the immune response to clot-targeted antithrombotics with the design of functionally deimmunized TAP variants through deletion of immunogenic T cell epitopes. The cellular immunogenicity of TAP (tick anticoagulant peptide) will be assessed and T cell epitopes, which drive the response mapped in naïve human peripheral blood mononuclear cells. Computational tools will be used to design functionally deimmunized TAP variants that will be evaluated in vitro and ex vivo for their maintenance of FXa inhibitory activity and their reduction of cellular immunogenicity. The wild type and resulting lead candidate will be assessed for cellular and humoral immunogenicity in vivo in humanized HLA transgenic mice. The successful deimmunization of TAP will allow us to generate deimmunized clot-targeted antithrombotics.

项目概要 我们目前缺乏有效的治疗方法来降低静脉血栓栓塞的风险 随之而来的出血风险。组建的调查小组最近发现了单链抗体 选择性地阻断活化的血小板并丰富正在形成的血栓部位的治疗效果。在 过程中，我们发现选择性靶向活化血小板可以实现多种 抗血栓药物是有效的，远低于引起出血的全身浓度。在这个 建议，我们假设选择性靶向活化血小板提供了一种局部浓缩的方法 在不破坏静脉血栓生长部位的情况下使用抗血小板剂、抗凝剂和纤溶剂 重要的止血过程。我们相信这一策略将有助于设计高效能药物 静脉血栓预防，但不会增加大出血的风险。在本提案中，我们打算： (1) 明确凝块靶向“双途径”抗血栓药预防静脉血栓形成的能力 并抑制血栓后静脉壁纤维化，且不影响止血。 “双效”的功效 基于 SCE5-TAP 的抗血栓药物，SCE5-TAP 是一种具有抗血小板和抗凝作用的单链抗体 将使用静脉血栓形成的小鼠模型来定义活性。这些研究将评估 SCE5-TAP 和相关新变体可预防静脉血栓形成、限制早期和晚期炎症 反应，并抑制血栓引起的静脉壁重塑，而不会造成止血障碍。 (2) 确定具有抗血小板和纤溶作用的凝块靶向抗血栓药物的能力 抑制静脉血栓形成和血栓后静脉壁重塑的活性。的有效性 基于 SCE5-scuPA 的抗血栓药，一种具有抗血小板和纤溶活性的单链抗体，将 单独使用静脉血栓形成的小鼠模型或与 SCE5-TAP 或相关新模型组合来定义 变种。我们还将设计重组凝块靶向混合构建体 (SCE5-TAP-scuPA)，该构建体显示 抗血小板、抗凝和纤溶活性。这些药物具有抑制血栓形成、促进血栓形成的能力。 血栓溶解，并限制静脉壁纤维化的发展将被确定。 (3)通过功能性设计减轻对凝块靶向抗血栓药的免疫反应 通过删除免疫原性 T 细胞表位来消除 TAP 变体的免疫。蜂窝式 将评估 TAP（蜱抗凝肽）的免疫原性和驱动 T 细胞表位 在幼稚的人外周血单核细胞中绘制反应。计算工具将用于 设计功能性去免疫 TAP 变体，对其维持进行体外和离体评估 FXa 抑制活性及其细胞免疫原性的降低。野生型和产生的铅 将在人源化 HLA 转基因小鼠体内评估候选药物的细胞和体液免疫原性。 TAP 的成功去免疫将使我们能够生产去免疫的凝块靶向抗血栓药物。