Switching a Xanthine Oxidase Inhibitor to a Dual-Target Antagonist of P2Y1 and P2Y12 as an Oral Antiplatelet Agent with a Wider Therapeutic Window in Rats than Ticagrelor.

ADP-mediated platelet aggregation is signaled through G protein-coupled receptors P2Y1 and P2Y12 on the platelet. The clinical effectiveness of inhibiting P2Y12 has been well established, and preclinical studies indicated that the inhibition of P2Y1 could provide equivalent antithrombotic efficacy as P2Y12 antagonists and reduce bleeding risks. On the basis of the 2-phenyl-1H-imidazole scaffold of our previously reported xanthine oxidase inhibitor WSJ-557, we first achieved the transition from the xanthine oxidase inhibitors to dual-target antagonists against P2Y1 and P2Y12. We described the structure-activity relationships of the 2-phenyl-1H-imidazole compounds, which led to the identification of the most potent antiplatelet agents, 24w and 25w, both showing a rapid onset of action in pharmacokinetic study. Furthermore, the rat model suggested that 24w demonstrated a wider therapeutic window than ticagrelor, displaying equivalent and dose-dependent antithrombotic efficacy with lower blood loss compared to ticagrelor at same oral dose. These results supported that 24w and 25w could be promising drug candidates.