Double-blind, placebo-controlled Phase II studies of the protease-activated receptor 1 antagonist E5555 (atopaxar) in Japanese patients with acute coronary syndrome or high-risk coronary artery disease

Abstract

E5555 (50, 100, and 200 mg) did not increase clinically significant bleeding, although there was a higher rate of any TIMI bleeding with the highest two doses. All doses tested achieved a significant level of platelet inhibition. There was a significant dose-dependent increase in liver function abnormalities and QTcF. Although further study is needed, PAR-1 antagonism may have the potential to be a novel pathway for platelet inhibition to add on to the current standard of care therapy.