2018, Apixaban to Prevent Venous Thromboembolism in Patients with Cancer, NEJM
The AVERT trial evaluated the use of apixaban for preventing venous thromboemboli such as deep venous thrombosis and pulmonary embolism in patients with cancer who were scheduled to start chemotherapy. These patients were at high risk of VTE based on the Khorana score.
The point that differentiated AVERT trial from other similar trials of using drugs for prevention of VTE in cancer patients was that it enrolled patients who did not have a history of VTE and the primary target was to lower the first incidence of VTE. In comparison, the CLOT and Hokusai VTE trials studied the use of LMWH for secondary prevention of VTE.
The study did show benefits of apixaban in preventing the first episode of VTE but this was countered by significant increase in bleeding risk. Currently based on guidelines, LMWH are preferred agents of choice for secondary prevention of VTE in patients with cancer. The 2012 CHEST guidelines on antithrombotic therapy recommend:
In patients with DVT of the leg and cancer, we suggest LMWH over VKA therapy (Grade 2B). In patients with DVT and cancer who are not treated with LMWH, we suggest VKA over dabigatran or rivaroxaban for long-term therapy (Grade 2B).Source