Cancer puts patients at greater risk for venous thromboembolism (VTE), but researchers recently reported in The New England Journal of Medicine that therapy with apixaban may reduce this risk in patients taking chemotherapy at intermediate or greater risk for VTE.
In a double blind trial (ClinicalTrials.gov Identifier: NCT02048865) of efficacy and safety, ambulatory patients with cancer who were beginning treatment with chemotherapy were randomly assigned to receive either apixaban 2.5 mg twice daily (288 patients) or a placebo (275 patients).
Apixaban was used as a preventive measure against VTE. The primary efficacy outcome was occurrence of VTE during the 180-day follow-up period. The primary safety outcome measured was incidence of a major bleeding episode.
An intention-to-treat analysis revealed that 4.2% of patients in the apixaban cohort experienced VTE compared with 10.2% of patients receiving the placebo (hazard ratio [HR], 0.41; 95% CI: 0.26-0.65; P <.001).
Major bleeding occurred among 3.5% of patients in the apixaban cohort and among 1.8% of patients taking placebo (HR, 2.00; 95% CI: 1.01-3.95; P =.046) in a modified intention-to-treat analysis. During treatment, 2.1% of patients receiving apixaban experienced major bleeding compared with 1.1% patients receiving placebo (HR: 1.89; 95% CI: 0.39-9.24). Three of the 15 total major bleeding events in this study were deemed clinical emergencies.
There were deaths among 12.2% of patients receiving apixaban and 9.8% of those receiving the placebo, with 87% of the total deaths attributed to cancer-related causes.
Although apixaban prophylaxis was associated with more occurrences of major bleeding among patients in this study, it appeared to lead to a lower incidence of VTE when taken at a dose of 2.5 mg twice per day.
1. Carrier M, Abou-Nassar K, Mallick R, et al. Apixaban to prevent venous thromboembolism in patients with cancer [published online February 21, 2019]. N Engl J Med. doi: 10.1056/NEJMoa1814468