Boston—The risk of venous thromboembolism (VTE) is calculated to be seven times greater in cancer patients than those without. Based on long-term practice guidelines, patients with cancer and VTE are recommended to receive treatment with LMWH, which requires SC administration, based on efficacy studies demonstrating superiority compared with warfarin.

A new study raises the question of whether LMWH is superior to DOACs. Background information in the report in the Journal of the American Medical Association pointed out that four DOACs—dabigatran, rivaroxaban, apixaban, and edoxaban—were approved by the FDA for the treatment of VTE from 2012 to 2015.

Those approvals were based on randomized clinical trials that demonstrated similar efficacy and safety compared with warfarin in patients with atrial fibrillation or undergoing orthopedic surgery, the Dana-Farber/Brigham and Women's Cancer Center and Harvard Medical SchoolÐled researchers pointed out.

The trials either excluded patients with cancer altogether or included few participants with cancer, however. "Therefore, the effectiveness and safety of DOACs for patients with cancer and VTE remain unclear," the authors advised.

As a result, the study team sought to determine if, in cancer patients with a VTE event, DOACs are noninferior to LMWH for preventing recurrent VTE events.

The pragmatic, noninferiority randomized clinical trial included 638 patients from 67 centers with cancer and a new VTE. The results indicated that compared with LMWH, DOACs resulted in a recurrent VTE rate of 6.1% versus 8.8% at 6 months. "The upper confidence limit around the difference was less than the noninferiority margin of 3%," the researchers noted.

Specifically, in the study conducted between December 2016 and April 2020, participants had a median age of 64 years and 55% were women. Among the patients randomized to a DOAC, 330 received at least one dose. Among those randomized to LMWH, 308 received at least one dose.

"Of 6 prespecified secondary outcomes, none were statistically significant," the authors wrote. "Major bleeding occurred in 5.2% of participants in the DOAC group and 5.6% in the LMWH group (difference, –0.4%; 1-sided 95% CI, –100% to 2.5%) and did not meet the noninferiority criterion. Severe adverse events occurred in 33.8% of participants in the DOAC group and 35.1% in the LMWH group. The most common serious adverse events were anemia and death."

Those findings led to the conclusion that DOACs were noninferior to LMWH for preventing recurrent VTE over a 6-month follow-up in adults with cancer and VTE.

"Among adults with cancer and VTE, DOACs were non-inferior to LMWH for preventing recurrent VTE over 6-month follow-up," the researchers concluded. "These findings support use of a DOAC to prevent recurrent VTE in patients with cancer."

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

 « Click here to return to Weekly News.