The aptamer ARC1779 blocks von Willebrand factor-dependent platelet function in patients with thrombotic thrombocytopenic purpura ex vivo.

Background: In thrombotic thrombocytopenic purpura (TTP), ultralarge von Willebrand factor (VWF) multimers bind platelet (PLT) glycoprotein Ib and lead to the formation of disseminated fibrin-poor, VWF-rich PLT thrombi. The aptamer ARC1779 blocks binding of the VWF A1 domain to PLT glycoprotein Ib. We evaluated whether ARC1779 inhibits the excessive VWF activity and VWF-mediated PLT function in patients with TTP.

The aptamer ARC1779 is a potent and specific inhibitor of von Willebrand Factor mediated ex vivo platelet function in acute myocardial infarction.

ARC1779 is an aptamer, which blocks binding of the von Willebrand Factor (VWF) A1 domain to platelet GPIb receptors. VWF is increased in the elderly an in the setting of acute myocardial infarction (AMI), as reflected by increased shear-dependent platelet function. We hypothesized that ARC1779 concentration-dependently inhibits ex vivo platelet function, and that this concentration effect relationship may be shifted in patients with AMI.

Anti-von Willebrand factor aptamer ARC1779 for refractory thrombotic thrombocytopenic purpura.

Background: Plasma exchange is the main therapy for thrombotic thrombocytopenic purpura (TTP). No treatments other than plasma exchange have been documented to be effective nor are approved for treatment of TTP. The anti-von Willebrand factor (VWF) aptamer ARC1779 effectively inhibits VWF activity in plasma samples of TTP patients and thus shear-dependent platelet (PLT) function as measured by the PLT function analyzer PFA-100 (Dade Behring).