Use of the REG1 anticoagulation system in patients with acute coronary syndromes undergoing percutaneous coronary intervention: results from the phase II RADAR-PCI study

We sought to determine the feasibility of conducting percutaneous coronary intervention (PCI) in high-risk acute coronary syndrome (ACS) patients utilising the REG1 system consisting of pegnivacogin, an aptameric factor IXa inhibitor, and its controlling agent anivamersen. In RADAR, ACS patients were randomised to pegnivacogin 1 mg/kg with 25%, 50%, 75%, or 100% anivamersen reversal or unfractionated heparin. Of the 640 patients randomised, 388 (61%) underwent PCI. Major modified ACUITY 30-day bleeding rates were 18% (25% reversal), 12% (50% reversal), 9% (75% reversal), and 7% (100% reversal), compared with 11% with heparin. The corresponding total bleeding rates were 68%, 39%, 35%, 34%, and 38% (heparin). Ischaemic events were less frequent in those receiving pegnivacogin versus heparin (4.4% vs. 7.3%, p=0.3). Thirty-day urgent TVR (1.1% vs. 0.9%, p=1.0), myocardial infarction (4.0% vs. 6.4%, p=0.3), and angiographic complication (11.2% and 10.8%, p=0.9) rates were similar with pegnivacogin and heparin. There were no incidences of clot formation on guidewires or catheters. High-level factor IXa inhibition in ACS patients undergoing PCI, with at least 50% reversal, has a favourable bleeding profile and appears effective at suppressing ischaemic events and thrombotic complications. Larger phase trials in PCI are warranted. ClinicalTrials.gov NCT00932100