Study design and findings
From April 2019 to June 2022, the researchers enrolled and randomly assigned 604 patients with active cancer who had newly diagnosed isolated distal DVT, confirmed by ultrasonography, and were scheduled for DVT treatment with anticoagulation therapy, at 60 centers.
Active cancer was defined as a cancer diagnosis or cancer treatment (surgery, chemotherapy, radiotherapy, etc.) within 6 months of randomization, or current recurrence, local invasion, distant metastases, or hematopoietic malignancy without complete remission.
The most common reasons for ultrasonography were elevated D-dimer levels (62%) and suspected DVT because of symptoms (20%).
The patients had a mean age of 70.8 years and 28% were men. The most common cancer sites were ovaries (14%), uterus (13%), lung (11%), colon (9%), and pancreas (8%), followed by stomach, blood, and breast (each 5%).
The patients were randomly assigned 1:1 to receive 12 months or 3 months of oral edoxaban at a dose of 60 mg once daily or 30 mg once daily in patients with body weight of 60 kg or less, creatinine clearance of 30-50 mL/minute, or concomitant treatment with a potent P-glycoprotein inhibitor.
After excluding 3 patients who withdrew consent, 601 patients were included in the intention-to-treat population: 296 patients in the 12-month edoxaban group and 305 patients in the 3-month edoxaban group.
About 70% of patients had a body weight of 60 kg or less and about 22% had a creatinine clearance less than 50 mL/min. About three quarters received the lower dose of edoxaban.
In the 12-month edoxaban group, 223 patients completed the 1-year follow-up (66 patients had died and 7 were lost to follow-up). In the 3-month edoxaban group, 224 patients completed the 1-year follow-up (77 had died and 4 were lost to follow-up).
In the 12-month edoxaban group, 41% of the patients had discontinued treatment by 12 months. In the 3-month edoxaban group, 41% of patients had discontinued treatment by 3 months.
The primary endpoint – a symptomatic recurrent VTE event or VTE-related death – occurred in 3 of the 222 patients (1.2%) in the 12-month edoxaban group and in 22 of the 210 (8.5%) in the 3-month edoxaban group (odds ratio,0.13; 95% confidence interval, 0.03-0.44, P < .001). There were no VTE-related deaths.
The major secondary endpoint – major bleeding, according to International Society on Thrombosis and Hemostasis criteria – occurred in 28 of the 210 patients (10.2%) in the 12-month edoxaban group and in 22 of the 217 (7.6%) in the 3-month edoxaban group (OR, 1.34; 95% CI, 0.75-2.41, P = NS).
The researchers acknowledged that study limitations include an open-label design, a lower-than-expected primary endpoint rate, and less than high adherence to edoxaban, as well as the need for caution when generalizing the results to other populations.
The study was funded by Daiichi Sankyo. Dr. Yamashita disclosed receiving lecture fees from Bayer Healthcare, Bristol-Myers Squibb, Pfizer, and Daiichi Sankyo, and grant support from Bayer Healthcare and Daiichi Sankyo. Dr. Lopez-Fernandez disclosed receiving speaker fees from Phillips, Janssen, Daiichi Sankyo, Myocardial Solutions, AstraZeneca, Pfizer, Beigene, and Bayer not related to this study.
A version of this article appeared on Medscape.com.