NEW ORLEANS – A novel targeted ticagrelor reversal agent demonstrated rapid and sustained reversal of the potent antiplatelet agent in a phase 1 proof-of-concept study, , reported at the annual meeting of the American College of Cardiology.
“Hopefully the FDA will view this as something that really is a breakthrough,” commented Dr. Bhatt, executive director of interventional cardiology programs at Brigham and Women’s Hospital and professor of medicine at Harvard University, both in Boston.
Why a breakthrough? Because despite recent major advances in the ability to reverse the action of the direct-acting oral anticoagulants and thereby greatly improve their safety margin, there have been no parallel developments with regard to the potent antiplatelet agents ticagrelor (Brilinta), prasugrel (Effient), and clopidogrel. The effects of these antiplatelet drugs take 3-5 days to dissipate after they’ve been stopped, which is highly problematic when they’ve induced catastrophic bleeding or a patient requires emergent or urgent surgery, the cardiologist explained.
“The ability to reverse tigracelor’s antiplatelet effects rapidly could distinguish it from other antiplatelet agents such as prasugrel or even generic clopidogrel and, for that matter, even aspirin,” Dr. Bhatt said.
The ticagrelor reversal agent, known for now as PB2452, is an intravenously administered recombinant human immunoglobulin G1 monoclonal antibody antigen-binding fragment. It binds specifically and with high affinity to ticagrelor and its active metabolite. In the phase 1, placebo-controlled, double-blind study conducted in 64 healthy volunteers pretreated with ticagrelor for 48 hours, it reversed oral ticagrelor’s antiplatelet effects within 5 minutes and, with prolonged infusion, showed sustained effect for at least 20 hours.
The only adverse events observed in blinded assessment were minor injection site issues.
PB2452 is specific to ticagrelor and will not reverse the activity of other potent antiplatelet agents. Indeed, because of their chemical structure, neither prasugrel nor clopidogrel is reversible, according to Dr. Bhatt.