Abstract 9771: Reg1, a Novel RNA-Aptamer Direct Factor IXa-inhibitor (pegnivacogin) Reduces Platelet Activation in Healthy Volunteers and Residual Platelet Aggregation in Patients with ACS. A Radar Substudy

Background and Rationale: Residual platelet reactivity is a predictor of cardiovascular adverse events in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary interventions (PCI). In addition to patient factors and antiplatelet therapy, the choice of anticoagulant determines the risk for periprocedural ischemic and bleeding events. The ideal anticoagulant would demonstrate a fast onset, effective anticoagulation, and controlable reversibility. REG1 consisting of pegnivacogin, a RNA-aptamer direct factor IXa inhibitor, and anivamersen, its specific, and titratable active control agent meets these requirements. We examined whether inhibition of factor IXa with pegnivacogin affects platelet reactivity in vitro and in vivo in healthy volunteers and in a subset of patients with ACS undergoing PCI from the phase IIb RADAR trial (NCT00932100). Methods and Results: For the in vitro study, blood from healthy volunteers was spiked with pegnivacogin (50µg/ml) and ADP-induced platelet activat...