JTV-803 is a factor Xa inhibitor. JTV-803 showed a competitive inhibitory effect on human factor Xa, with a K(i) value of 0.019 microM and IC(50) value of 0.081 microM. JTV-803 was 100 times more selective in inhibiting human factor Xa as compared to its inhibitory activity against thrombin, trypsin and plasmin. JTV-803 prolonged activated partial thromboplastin time and prothrombin time in a dose-dependent manner.