Background: Guidelines recommend oral factor Xa inhibitors for the treatment of cancer-associated thrombosis (CAT) in patients considered low-risk of bleeding and without a potential for drug-drug interaction with systemic therapy.

Aims: To evaluate the effectiveness and safety of rivaroxaban versus low molecular-weight heparin (LMWH) for the treatment of CAT.

Methods: Using US Surveillance, Epidemiology and End Results (SEER)-Medicare-linked data from 2013-2016, we identified adults with primary lung, breast, pancreatic, prostate, ovarian or bladder cancer, experiencing a hospitalization or emergency department admission with a primary diagnosis code for venous thromboembolism (VTE) within 2-years of cancer diagnosis or while actively treated for cancer, ≥12-months of continuous benefits prior to the index CAT and who received rivaroxaban or a LMWH as their first outpatient anticoagulant. Patients with oral, esophageal, stomach, colorectal or brain cancer were excluded. Rivaroxaban and LMWH cohorts were 1:1 propensity-scored matched (standard differences< 0.10 achieved for all covariates). Outcomes included the composite of recurrent VTE or major bleeding at 12-months and recurrent VTE, major bleeding and all-cause mortality individually. Cohorts were compared using Fine-Gray (competing risk) Cox regression.

Results: We included 684 rivaroxaban and 684 LMWH-managed patients. Thirty-three percent of patients were ≥75-years-of-age, 43.8% had a pulmonary embolism as their index event and most were diagnosed with stage 2 (45.5%) or 3 (52.0%) disease. Nearly 72% of CAT occurred within 2-years of patients’ initial cancer diagnosis, with 67.9% of patients undergoing active cancer treatment at time of thrombosis. At 12-months, there was no difference in the composite endpoint of recurrent VTE or major bleeding, either component alone or all-cause mortality between the rivaroxaban and LMWH cohorts (Figure).

Conclusions: In this real-world study of rivaroxaban- and LMWH-managed CAT patients, no difference in patients’ risk of experiencing the composite outcome, recurrent thrombosis, major bleeding or all-cause mortality were observed between anticoagulant strategies.

[Figure. Incidence rates and hazard ratios for recurrent VTE, major bleed, and death.]

« Back to ISTH 2020 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/effectiveness-and-safety-of-rivaroxaban-in-patients-with-cancer-associated-venous-thromboembolism/