Platelet-targeted dual pathway antithrombotic inhibits thrombosis with preserved hemostasis
Donny Hanjaya-Putra, … , Karlheinz Peter, Elliot L. Chaikof
Donny Hanjaya-Putra, … , Karlheinz Peter, Elliot L. Chaikof
Published August 9, 2018
Citation Information: JCI Insight. 2018;3(15):e99329. https://doi.org/10.1172/jci.insight.99329.
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Research Article Cardiology Hematology

Platelet-targeted dual pathway antithrombotic inhibits thrombosis with preserved hemostasis

Abstract

Despite advances in antithrombotic therapy, the risk of recurrent coronary/cerebrovascular ischemia or venous thromboembolism remains high. Dual pathway antithrombotic blockade, using both antiplatelet and anticoagulant therapy, offers the promise of improved thrombotic protection; however, widespread adoption remains tempered by substantial risk of major bleeding. Here, we report a dual pathway therapeutic capable of site-specific targeting to activated platelets and therapeutic enrichment at the site of thrombus growth to allow reduced dosing without compromised antithrombotic efficacy. We engineered a recombinant fusion protein, SCE5-TAP, which consists of a single-chain antibody (SCE5) that targets and blocks the activated GPIIb/IIIa complex, and tick anticoagulant peptide (TAP), a potent direct inhibitor of activated factor X (FXa). SCE5-TAP demonstrated selective platelet targeting and inhibition of thrombosis in murine models of both carotid artery and inferior vena cava thrombosis, without a significant impact on hemostasis. Selective targeting to activated platelets provides an attractive strategy to achieve high antithrombotic efficacy with reduced risk of bleeding complications.

Authors

Donny Hanjaya-Putra, Carolyn Haller, Xiaowei Wang, Erbin Dai, Bock Lim, Liying Liu, Patrick Jaminet, Joy Yao, Amy Searle, Thomas Bonnard, Christoph E. Hagemeyer, Karlheinz Peter, Elliot L. Chaikof

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Figure 2

SCE5-TAP targets arterial thrombus and inhibits occlusion in mice.

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SCE5-TAP targets arterial thrombus and inhibits occlusion in mice. Plate...
Platelet-specific anti–CD42b–Dylight 649 was infused and thrombus formation induced by laser injury and was characterized over time. (A) Representative images of the fluorescence signal associated with platelet thrombus after laser injury of cremaster arterioles. Saline, MUT-TAP (0.03 μg/g), or SCE5-TAP (0.03 μg/g) were administered (i.v.) up to 30 minutes prior to laser injury. (B) Median integrated platelet fluorescence with administration of saline (red), MUT-TAP (blue), or SCE5-TAP (green). (C) Platelet accumulation was quantified as the AUC as calculated for platelet relative fluorescence units (RFU). Units are arbitrary and data represent mean ± SD, n = 20–34 vessels in 4–5 mice/group. (D) Carotid artery thrombosis was induced with ferric chloride, and construct targeting was confirmed using IVIS scan with IR800-labeled MUT-TAP or SCE5-TAP. (E) Ferric chloride-induced carotid artery thrombus development was monitored with a nano-flow probe. A significant increase in occlusion time was observed with SCE5-TAP (0.03 and 0.3 μg/g) and with reference compounds LMWH (enoxaparin, 10 μg/g) and Ept (eptifibatide, 10 μg/g). Tail transection performed 1 minute after i.v. administration revealed a significant prolongation of (F) bleeding time and (G) bleeding volume for reference agents, LMWH (enoxaparin, 10 μg/g), and Ept (eptifibatide, 10 μg/g), but not for SCE5-TAP (0.03 μg/g). Data represent mean ± SD, n = 4 per group, *P ≤ 0.05, **P ≤ 0.01, and ***P ≤ 0.001 (ANOVA and Bonferroni’s multiple comparison test).