Bristol-Myers Squibb Company and Pfizer have discontinued a Phase III clinical trial of apixaban, an investigational oral factor Xa inhibitor, following safety concerns.

The independent Data Monitoring Committee recommended that the trial, involving patients with recent acute coronary syndrome, be discontinued after evidence of clinically important bleeding in patients receiving the drug emerged.

In addition, this increase in bleeding was not offset by meaningful reductions in ischemic events.

The study involved 10,800 in 40 countries, who were randomised to receive 5mg of apixaban twice daily or a placebo.

The companies have informed the study investigators, ethics review boards and regulatory health authorities about their decision to stop the study.