Extended Anticoagulation Therapy With Rivaroxaban for Cancer‐Associated Low‐Risk Pulmonary Embolism According to Different Performance Status Scores: Insights From the ONCO PE Randomized Trial

Background The ONCO PE (Optimal Duration of Anticoagulation Therapy for Low‐Risk Pulmonary Embolism Patients With Cancer) trial demonstrated the superiority of 18‐month compared with 6‐month rivaroxaban treatment for cancer‐associated low‐risk pulmonary embolism in reducing recurrent venous thromboembolism. However, it was uncertain whether the results could be applicable to patients with different performance status (PS) scores, which evaluate the physical condition of patients with cancer undergoing anticancer treatment. Methods In this post hoc subgroup analysis of the ONCO PE trial, we compared the 18‐month and 6‐month rivaroxaban treatment groups in 2 subgroups: the low PS score (no restricted physical activity: PS=0; n=79) and high PS score (restricted physical activity: PS ≥1; n=99) subgroups. The primary end point was recurrent venous thromboembolism, and the major secondary end point was major bleeding. Results The rate of recurrent venous thromboembolism was lower in the 18‐month rivaroxaban group than in the 6‐month rivaroxaban group, significantly among the low PS score subgroup (2.7% versus 19.0%, P =0.049) and numerically among the high PS score subgroup without statistical significance (7.7% versus 19.1%, P =0.10). The rate of major bleeding was not different between the 2 groups among the low PS score subgroup (2.7% versus 7.1%, P =0.39), while it was numerically higher in the 18‐month rivaroxaban group than in the 6‐month rivaroxaban group among the high PS score subgroup, without statistical significance (11.5% versus 4.3%, P =0.20). Conclusions Extended anticoagulation therapy for patients with cancer‐associated low‐risk pulmonary embolism might have a potential benefit in reducing thrombotic risk irrespective of PS score, whereas there might be some concerns on an increased risk of major bleeding in patients with a high PS score. Registration URL: https://www.clinicaltrials.gov ; Unique Identifier: NCT04724460.