UR-2922 is a new generation oral platelet GPIIb/IIIa antagonist. UR-2922 is the active form of the prodrug UR-3216. UR-2922 possessed a high affinity for the human platelet receptor (K(d) <1 nM) with a slow dissociation rate (k(off)= 90 min) in vitro. UR-2922 induced no ligand-induced binding sites (LIBS) expression or prothrombotic activity in human platelets, distinctly different from orbofiban and other small molecule antagonists.
