Apixaban, an anticoagulant being jointly developed by Bristol-Myers Squibb and Pfizer, has shown good results as an agent to reduce the incidence of venous thromboembolism (VT) in patients undergoing total knee replacement surgery.

The ADVANCE-2 study found apixaban to be statistically superior to 40mg once-daily enoxaparin and also showed numerically lower rates of major and clinically relevant non-major bleeding compared to enoxaparin.

The oral selective Factor Xa inhibitor anti-clotting pill apixaban is part of a class of agents being studied for their potential to prevent and treat blood clots in the veins and arteries.

VT, which affects 40–60% of patients who undergo orthopaedic surgery in the absence of preventive care, can cause two major complications; deep vein thrombosis, a blood clot in a vein, and pulmonary embolism, a blood clot blocking a vessel in the lungs.

Apixaban is in Phase III trials, studying the prevention of stroke and other thromboembolic events in patients with atrial fibrillation, patients with acute coronary syndrome and treatment of VT.

Apixaban is being investigated within the EXPANSE Clinical Trials Program, which is projected to include nearly 60,000 patients and will include a total of nine completed or ongoing, randomised, double-blind Phase III trials, including ADVANCE-2.

Pfizer and Bristol-Myers Squibb entered into a worldwide collaboration to develop and commercialise apixaban in 2007.