Apixaban trumps standard treatment in preventing cancer-associated VTE recurrence
Apixaban slashes the risk of recurrent venous thromboembolism (VTE) by 90 percent in cancer patients compared with the low-molecular-weight heparin (LMWH) dalteparin, with no increase in major bleeding risk, according to the ADAM VTE study presented at ASH 2018.
“Nearly one in five patients with cancer will develop a clot in the veins … Clotting events can be deadly, with pulmonary embolism being the second most common cause of death in [patients with] cancer,” said Dr Robert McBane from the Mayo Clinic in Rochester, Minnesota, US.
LMWH is the guideline-recommended treatment for cancer-associated VTE, but LMWH injections are expensive and can cause bruising and pain at the injection site, said McBane. “Patients [with cancer] may experience low platelet counts and be at risk for a clotting disorder called heparin-induced thrombocytopenia.” Also, kidney injury induced by cancer therapy can further limit the use of LMWH.
Compared with the LMWH dalteparin, apixaban significantly reduced the risk of recurrent VTE in cancer patients by 90.1 percent (hazard ratio [HR], 0.099; p=0.03), with VTE recurrence observed in 0.7 percent of apixaban-treated patients vs 6.3 percent in the dalteparin group. [ASH 2018, abstract 421]
Major bleeding rates were comparable between the apixaban and dalteparin groups (0 percent vs 1.4 percent; p=0.14), indicating that apixaban is safe. Major plus clinically relevant nonmajor bleeds also occurred at similar rates in both groups (6.2 percent vs 6.3 percent; p=0.88).
There were no significant differences in mortality rates at 6 months between the two groups (HR, 1.40; p=0.31).
Based on monthly quality-of-life surveys, patients showed that they preferred apixaban over dalteparin when considering burden of delivery, concerns for excess bruising, irritation, stress, and overall satisfaction with anticoagulants (p<0.05).
“Apixaban was well tolerated with superior patient satisfaction and significantly fewer study drug discontinuations compared with dalteparin,” said McBane, who noted that more patients in the dalteparin group discontinued treatment compared with the apixaban group (15 percent vs 4 percent; p=0.0012). “These data support the use of apixaban for the acute treatment of cancer-associated VTE.”
The multicentre, open-label trial randomized 287 patients (mean age, 64 years) with cancer in a 1:1 ratio to receive apixaban twice daily (10 mg for 7 days followed by 5 mg dose) or subcutaneous dalteparin (200 IU/kg for 1 month and subsequently 150 IU/kg once daily) for 6 months. About two-third of the patients (65.5 percent) had metastatic disease, with lung, pancreas, colorectal, and breast cancers being the four most prevalent cancer types.
“As a class, [direct oral anticoagulants] have a number of advantages, including oral delivery, lack of interactions with foods or other medications, and the lack of a need for monitoring drug levels,” said McBane.
“We are hopeful that this medication will also improve medication compliance in patients [with cancer] requiring blood thinner therapy,” he added.