ISTH Congress Abstracts

Official abstracts site for the ISTH Congress

MENU 

Effect of Novel Thrombolytic Aptamer DTRI-031 on Microfluidic Thrombolysis and VWF Function Dose-Response

1Trauma and Transfusion Medicine Research Center, Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, 2Department of Pediatrics, Washington University in St. Louis, St. Louis, Missouri, United States, 32. Department of Pediatrics, Washington University in St. Louis, St. Louis, Missouri, United States, 4Trauma and Transfusion Medicine Research Center, Department of Surgery, University of Pittsburgh, Pittsburgh, PA; Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, Pittsburgh, Pennsylvania, United States, 5Department of Neurological Surgery, The Ohio State University Medical Center, Columbus, Ohio, United States

Abstract Number: PB0644

Meeting: ISTH 2022 Congress

Theme: Fibrinolysis and Proteolysis » Thrombolytic Therapy

Background: The interaction between von Willebrand Factor (VWF) A1 domain and platelet GPIbα is essential for arterial thrombosis. Aptamer DTRI-031 selectively inhibits VWF A1 and has potent thrombolytic properties. The ideal clinical assay to detect DTRI-031 functional efficacy and the corresponding therapeutic range are unknown. We measured dose responsiveness of DTRI-031 in a custom microfluidic model of thrombolysis and currently available clinical assays.

Aims: The aim of this study is to determine the capacity of clinical assays to reflect microfluidic thrombolysis relative to measurable inhibition induced by DTRI-031.

Methods: Healthy human whole blood (WB, N&#3f10) was dosed with vehicle, 423nM, 846nM, 1692nM, or 3384nM DTRI-031 to approximate an in vivo dose range of 0.25-2mg/kg. VWF function was assayed via VWF:Ag, VWF:Ac (Siemens GP1bα-interaction specific assay, unavailable in US), T-TAS, VWF:RCo, ristocetin impedance aggregometry (RIA). WB was also stained with fluorescent CD41 antibody (platelet label) and perfused through a stenotic microfluidic chamber to induce partial thrombotic occlusion (25mmHg pressure increase), followed by DTRI-031 perfusion. Maximum reduction in thrombus surface was calculated using auto-thresholding (Python v3.10) of CD41-positive surface area yielding microfluidic lytic efficacy (MLE). One-way ANOVA and multiple comparisons were used to assess dose response. Pearson correlation coefficients were calculated between assays.

Results: VWF assays were inhibited by DTRI-031 (Figure 1) while VWF:Ag was, as expected, constant. MLE trended higher at the midrange dose. Correlation with dose was highest in VWF:Ac, VWF:RCo, and RIA, while MLE correlated best with T-TAS and VWF:Ag (Figure 2).

Conclusion(s): Inhibition of GPIbα by DTRI-031 is dose-dependent and measurable on currently available clinical assays. In a thrombolysis microfluidic model, 3384nM DTRI-031 was less efficacious than 1692nM DTRI-031, perhaps indicating off-target effects at the highest dose. MLE correlated best with T-TAS, a function-under-flow assay. Further investigation of DTRI-031 mechanisms will provide insight into discrepancies between static assays and flow-based assays.

Image

Figure 1. DTRI-031 dose-response on all assays. Asterisks denote statistical significance when compared to 0 nM DTRI-031 -vehicle-.

Image

Figure 2. Correlation matrix -Pearson’s R- for all assays.

To cite this abstract in AMA style:

Shea S, Rassam R, Thomas K, Daniel C, Spinella P, Nimjee S. Effect of Novel Thrombolytic Aptamer DTRI-031 on Microfluidic Thrombolysis and VWF Function Dose-Response [abstract]. https://abstracts.isth.org/abstract/effect-of-novel-thrombolytic-aptamer-dtri-031-on-microfluidic-thrombolysis-and-vwf-function-dose-response/. Accessed December 6, 2023.

« Back to ISTH 2022 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/effect-of-novel-thrombolytic-aptamer-dtri-031-on-microfluidic-thrombolysis-and-vwf-function-dose-response/