Impact of Anemia on Clinical Outcomes of Patients With Cancer-Associated Isolated Distal Deep Vein Thrombosis Receiving Edoxaban - Insights From the ONCO DVT Study.

BACKGROUND The ONCO DVT study demonstrated potential benefits of extended edoxaban treatment in patients with isolated distal deep vein thrombosis in terms of thrombotic risk. However, the risk-benefit balance in patients with anemia remains unclear. METHODS AND RESULTS This prespecified subgroup analysis included 601 patients, divided into anemia (n=402) and no-anemia (n=199) groups. The primary endpoint was symptomatic recurrent venous thromboembolism (VTE) or VTE-related death. Anemia was defined as hemoglobin <12 g/dL for women and <13 g/dL for men. In the anemia subgroup, the primary endpoint occurred in 3 (1.5%) and 17 (8.4%) patients in the 12- and 3-month edoxaban treatment groups, respectively (odds ratio [OR] 0.17; 95% confidence interval [CI] 0.05-0.58), compared with 0 and 5 (4.9%) patients, respectively, in the no-anemia subgroup (P interaction=0.997). Major bleeding occurred in 26 (13.1%) and 17 (8.4%) patients with anemia in the 12- and 3-month edoxaban treatment groups, respectively (OR 1.64; 95% CI 0.86-3.14), compared with 2 (2.1%) and 5 (4.9%) patients without anemia (OR 0.67; 95% CI 0.26-1.73; P interaction=0.13). CONCLUSIONS Regardless of the presence of anemia, edoxaban treatment for 12 months was superior to treatment for 3 months in reducing thrombotic events, whereas the risk of major bleeding did not differ significantly between the 2 treatment groups.