Having an inferior vena cava filter (IVCF) did not improve blood-clot prevention in cancer patients taking the anticoagulant agent fondaparinux (Arixtra), according to the results of a prospective study evaluating the treatment of venous thromboembolism (VTE) in persons with cancer.

“[This] is a potentially practice-changing clinical trial,” announced principal investigator Myra Barginear, MD, of the North Shore-Long Island Jewish Health System, Manhasset, New York, in a statement describing her group’s findings. The statement was issued by the International Association for the Study of Lung Cancer (IASLC), sponsor of the 14th World Conference on Lung Cancer, held July 3-7, 2011, in Amsterdam, the Netherlands, at which these findings were presented.

According to the IASLC statement, 1 in every 200 people with cancer experiences a VTE, and these clots are the second most common cause of death among cancer patients. A thin-mesh filter can be placed in the inferior vena cava to prevent a VTE from traveling to the heart.

However, in this study of 64 cancer patients with deep vein thrombosis (86%) or pulmonary embolism (55%), in which about half the group received only fondaparinux and the other half received fondaparinux in conjunction with an IVCF, the IVCF did not improve outcomes:

  • Median survival was 493 days for the fondaparinux-only group, compared with 266 days for patients who had both fondaparinux and the IVCF.
  • A median 52% of fondaparinux-only patients experienced a complete resolution of VTEs, compared with 45% of the patients with fondaparinux plus IVCF.

The IASLC announcement stated that these findings suggest IVCF placement, which is costly and invasive, does not benefit patients who are receiving fondaparinux. Furthermore, the results support the need for future randomized trials that would compare VTE resolution rates achieved with fondaparinux with low-molecular-weight heparin.