DOAC as good as heparin for treating VTE in cancer patients

By John Murphy, MDLinx
Published December 13, 2017

Key Takeaways

An oral anticoagulant pill is comparable to subcutaneous heparin injection for treating venous thromboembolism (VTE) in cancer patients, according to researchers presenting their study results at the 59th American Society of Hematology Annual Meeting and Exposition, on December 12, 2017, in Atlanta, GA.

A direct oral anticoagulant (DOAC) taken once daily offers an alternative and potentially more palatable treatment strategy to cancer patients, the presenters said.

About one in five people with cancer develops VTE. Yet, treating VTE remains a challenge in cancer patients because they are at increased risk of both recurrent VTE and major bleeding. “Importantly for oncologists, [these two complications] may interfere with what they really want to do, which is give definitive anticancer therapy to the patient,” said lead study author Gary E. Raskob, PhD, dean and regents professor of the University of Oklahoma College of Public Health, Oklahoma City, OK, who presented the results.

Low-molecular-weight heparin (LMWH) is the standard treatment for VTE in cancer patients, but it requires daily subcutaneous injections. Currently, DOACs are used to treat VTE in patients without cancer, but their role in treating patients with cancer-associated VTE isn’t known.

To that end, Dr. Raskob and other investigators of the Hokusai VTE-Cancer Study undertook the first large, randomized, controlled open-label trial to compare a daily DOAC (edoxaban) with daily subcutaneous LMWH (dalteparin) injection in patients with active cancer. Researchers enrolled 1,050 patients being treated for VTE at 114 centers in 13 countries. About 90% had solid tumors and about 10% had blood cancers; 53% of all patients had metastatic disease.

Investigators randomly assigned half of the patients to oral edoxaban and half to dalteparin injection.

After 12 months of treatment, patients given the DOAC had about the same percentage of recurrent VTEs or major bleeding events as those given LMWH—12.8% in the edoxaban group and 13.5% in the dalteparin group.

Edoxaban was associated with a slightly higher rate (+3.1%) of major bleeding than dalteparin, but this was offset by a lower risk (-3.8%) of recurrent VTE.

Severe major bleeding events were identical in both treatment groups (12 patients in each), and one-year survival free of recurrent VTE and major bleeding was also comparable (55.0% in the edoxaban group and 56.5% in the dalteparin group).

“For the vast majority of patients with cancer-associated VTE, treatment with oral edoxaban can replace the injectable dalteparin,” Dr. Raskob said. “Preventing VTE recurrence and major bleeding can allow the oncologist to really focus on the patient’s cancer treatment.”

These results don’t automatically apply to all DOACs because some act through different mechanisms or are metabolized differently than edoxaban, Dr. Raskob added. Further studies could determine which DOACs would work best for different chemotherapy regimens, and also identify optimal treatment regimens for patients with gastrointestinal cancers, he said.

This research was supported by Daiichi Sankyo.

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