New class of antiplatelet agents in clinical trials

 A new investigational antiplatelet agent, atopaxar (E5555; Eisai)—which acts via a different pathway from that of aspirin and drugs such as clopidogrel and ticagrelor—has shown promising results in a two-arm phase 2 trial in Japan, one part in ACS patients and the other in people with high-risk CAD.

 

The findings, which were published simultaneously in the European Heart Journal,were presented in a hot-line session here at the European Society of Cardiology 2010 Congress by Dr Shinya Goto (Tokai University School of Medicine, Japan). He said atopaxar showed the potential to reduce major adverse cardiovascular events (MACE) in both populations, although he stressed this was not the main focus of the trial, known as Japanese Lesson from Antagonizing the Cellular Effect of Thrombin (J-LANCELOT).

Atopaxar, a protease-activated receptor 1 (PAR-1) inhibitor that targets thrombin-induced platelet activation, also looks to have a good safety profile—there was a dose-dependent trend to an increased risk of nuisance bleeding in the study but no sign of any increase in clinically significant bleeding. However, there were some concerning signals with regard to liver function and prolongation of the QTc interval; but "in my mind, this drug should be tested in phase 3 trials," Goto said. The company developing the drug has not yet decided whether to go ahead with these, he noted. Another larger phase 2 trial with atopaxar, this time in mostly white, older patients, will be presented at TCT 2010 next month, he added.