Extended Anticoagulation Therapy with Rivaroxaban for Cancer-Associated Low-Risk Pulmonary Embolism According to Status of Concomitant Deep Vein Thrombosis: Insights from the ONCO PE Randomized Trial

The ONCO PE trial showed that 18-month rivaroxaban was superior to 6-month rivaroxaban for preventing recurrent venous thromboembolism (VTE) in patients with cancer-associated low-risk pulmonary embolism (PE). However, the influence of concomitant deep vein thrombosis (DVT) on this benefit was unclear. The current post-hoc subgroup analysis of the ONCO PE trial categorized patients into DVT subgroup (N=104) and no DVT subgroup (N=74) based on the presence or absence of a concomitant DVT at PE diagnosis. We compared the primary endpoint of 18-month recurrent VTE and the major secondary endpoint of 18-month major bleeding between the 18-month and 6-month rivaroxaban groups in the DVT and no DVT subgroups. The cumulative 18-month incidence of recurrent VTE in the 18-month rivaroxaban group was numerically lower compared with that in the 6-month rivaroxaban group in the DVT subgroup (11.5% vs. 20.9%, log-rank P=0.25) and was significantly lower in the no DVT subgroup (0.0% vs. 24.2%, log-rank P=0.006), without significant interaction between treatment durations and concomitant DVT (Pinteraction=0.99). There were no significant differences in the cumulative 18-month incidence of major bleeding between the 18-month and 6-month rivaroxaban groups in both the DVT (4.6% vs. 5.8%, log-rank P=0.70) and no DVT (13.4% vs. 5.8%, Log-rank P=0.29) subgroups, without significant interaction (Pinteraction=0.34). The current exploratory analysis showed that extended rivaroxaban treatment might have a potential benefit for patients with cancer-associated low-risk PE in preventing recurrent VTE, irrespective of concomitant DVT status, without a significantly increased risk of major bleeding.