Late breaking clinical trial results from testing of cangrelor, an investigational intravenous antiplatelet, showed patients can be “bridged” from the time that their physicians stop their oral antiplatelet drugs until they undergo cardiac surgery. Study results demonstrated cangrelor maintained target levels of platelet inhibition known to be associated with a low risk of thrombotic events, such as stent thrombosis, vs. placebo. The BRIDGE Trial results were presented at the Cardiovascular Research Foundation (CRF) annual Transcatheter Cardiovascular Therapeutics (TCT) conference on Nov 9.
“Patients with coronary stents require drugs that block platelets that can stick to their stents and cause clots. When these patients require surgery, the oral drugs must be stopped days in advance to wear off and reduce the risk of surgical bleeding; however, this puts them at an increased risk of thrombotic events,” said Eric Topol, MD, cardiologist and chief academic officer at Scripps Health and BRIDGE Trial primary investigator. “With nothing available that blocks platelets and then goes away quickly, we are between the rock of thrombosis and the hard place of surgical bleeding.”
BRIDGE results showed 99 percent of cangrelor-treated patients maintained target levels of platelet inhibition for all time points measured over the bridging period compared to 19 percent of placebo patients (p < 0.001). The primary safety measure demonstrated no significant excess in surgical bleeding complications (data below).
The results were presented by Dominick J. Angiolillo, MD, PhD, medical director, cardiovascular research program at the University of Florida College of Medicine Jacksonville, “BRIDGE results support the hypothesis that intravenous cangrelor may be a feasible and well tolerated management strategy in patients who require prolonged platelet P2Y12 inhibition after thienopyridine discontinuation prior to cardiac surgery. Results also show control of platelet function as there was a rapid offset of platelet inhibition after stopping the cangrelor infusion prior to surgery.”
According to 2009 data from the Organisation for Economic Co-operation and Development (OECD), more than 2.5 million PCIs are performed globally per year. Treatment guidelines in the United States and Europe recommend stent patients receive oral P2Y12 inhibitors for up to 12 months following percutaneous coronary intervention (PCI). It is estimated that up to 25 percent of these patients with stents in place will require a surgical procedure during the first five years after PCI.
Dimitrios Goundis, PhD, head of R&D at The Medicines Company added, “With strong patient enrollment in the Phase 3 PHOENIX trial of cangrelor in PCI patients and these results from the BRIDGE trial, there is great momentum with the cangrelor program, which is an important part of our portfolio of acute and intensive care hospital compounds.”
Summary methods and results
The first stage of BRIDGE identified the cangrelor dose that maintains a ‘thienopyridine-like’ level of platelet inhibition. The second stage reported on Nov 9 was a prospective, randomised, double-blind, placebo-controlled trial in 210 patients with an acute coronary syndromes (ACS) or treated with a coronary stent (bare metal stent or drug eluting stent) on a thienopyridine awaiting coronary artery bypass grafting (CABG). After thienopyridine discontinuation ( < 72 hours), patients were administered cangrelor or placebo for at least 48 hours and up to 7 days, which was discontinued 1-6 hours prior to CABG. The objective was to demonstrate that a cangrelor IV infusion would maintain levels of platelet reactivity < 240 P2Y12 Reaction Units (PRU) throughout the pre-operative period as measured by a P2Y12 assay. Platelet inhibition results are shown in this press release.
Cangrelor is an investigational agent not approved for commercial use in any market. Cangrelor, an intravenous small molecule antiplatelet agent, is in development to prevent platelet activation and aggregation that leads to thrombosis in the acute care setting of the cardiac catheterisation laboratory including in patients undergoing PCI. In October 2010, The Medicines Company initiated a Phase 3 clinical trial called PHOENIX to evaluate cangrelor in patients undergoing PCI.
(Source: The Medicines Company)
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