A DOAC Provides Heparin Alternative to Cancer Patients

Cancer patients face an increased risk for venous thromboembolism (VTEs). Under current guidelines, cancer patients who develop VTE are prescribed low-molecular-weight heparin as an anticoagulant.

"While effective, this regimen can be expensive and often burdensome for patients, leading many to prematurely discontinue treatment,” says the American Society of Hematology (ASH) in a statement.

As a result, researchers set out to compare the effects of dalteparin, a low-molecular-weight heparin, to a newer direct oral anticoagulant (DOAC), edoxaban (brand names Savaysa and Lixiana), on blood clots in cancer patients.

The study included around 1,050 cancer patients who were being treated for VTE at 114 centers in 13 countries. Around 10% of patients had blood cancers and the rest had solid tumors. Study results were presented at the ASH Annual Meeting and Exposition in December 2017.

Half of the cancer patients were randomly assigned to receive dalteparin and half were assigned to receive edoxaban for up to 12 months. All patients were followed for 12 months or until study closure, with a minimum of 9 months follow up.

The researchers, at the University of Oklahoma College of Public Health and other universities, found that edoxaban, taken as a daily pill, works as well as low-molecular-weight heparin and could offer an alternative, potentially more palatable treatment strategy. The results showed that edoxaban is not inferior to dalteparin with respect to composite rates of recurrent clots and bleeding, which occurred in 12.8% of those receiving edoxaban and 13.5% of those receiving dalteparin.

"For the vast majority of patients with cancer-associated VTE, treatment with oral edoxaban can replace the injectable dalteparin," says the study’s lead author, Gary E. Raskob, PhD, dean and regents professor at the University of Oklahoma College of Public Health. "Preventing VTE recurrence and major bleeding can allow the oncologist to really focus on the patient's cancer treatment."

“Although edoxaban was associated with a slightly higher rate of major bleeding, this was balanced by a slightly lower rate of recurrent VTE,” ASH said in its statement.

After researchers examined secondary outcomes and subgroups, they found that the two drugs were identical in the rates of the most severe category of major bleeding. Bleeding was most common in the upper gastrointestinal tract and in patients with gastrointestinal cancers.

However, these results do not necessarily apply to all DOACs, because some act through different mechanisms or are metabolized differently than edoxaban, Raskob says. Further studies could focus on which DOACs might work best in the context of different chemotherapy regimens and also illuminate optimal treatment regimens for those with gastrointestinal cancers, he added.

The study was supported by Daiichi Sankyo, the manufacturer of Lixiana.