Apixaban appeared more effective than rivaroxaban in preventing recurrent venous thromboembolism without major bleeding events, according to results of a retrospective study published in The Lancet Haematology.
“Although warfarin has been the drug of choice for decades, because of some constraints associated with its use, direct-acting oral anticoagulants such as rivaroxaban (Xarelto, Janssen) and apixaban (Eliquis, Bristol-Myers Squibb) are being increasingly used in routine clinical practice because of their conventional dosing and favorable pharmacological profiles,” Ghadeer K. Dawwas, MBA, of the department of pharmacotherapy and translational research at the University of Florida, and colleagues wrote. “To the best of our knowledge, this study is the first population-based cohort analysis to compare the effectiveness and safety of apixaban and rivaroxaban for the treatment of venous thromboembolism.”
Researchers used the Truven Health MarketScan commercial and Medicare Supplement claims databases to analyze 15,254 adults with newly diagnosed VTE — deep vein thrombosis or pulmonary embolism — who started using rivaroxaban (n = 12,163; mean age, 59.9 years; 50.4% women) or apixaban (n = 3,091; mean age, 61.6 years; 50.6% women) within 30 days of diagnosis.
Incidence of recurrent VTE served as the primary effectiveness outcome, with incidence of major bleeding events as the primary safety outcome.
Mean follow-up was 99 days in both groups.
Results showed a crude incidence of recurrent VTE of three per 100 person-years (25 cases) in the apixaban group and seven per 100 person-years (254 cases) in the rivaroxaban group. Incidence of major bleeding events was three per 100 person-years (28 cases) with apixaban and six per 100 person-years (188 cases) with rivaroxaban.
Multivariable Cox regression models showed using apixaban vs. rivaroxaban resulted in a decreased risk for recurrent VTE (HR = 0.37; 95% CI, 0.24-0.55) and major bleeding events (HR = 0.54; 95% CI, 0.37-0.82).
Limitations of this study included a lack of data on fatal outcome events in the outpatient setting, a lack of comparisons to other direct-acting oral anticoagulants, missing information on laboratory values and possible selection bias.
“Results from this study are therefore only generalizable to patients with VTE who are covered by commercial or Medicare Supplement Insurance and have had continuous coverage for at least 12 months,” Dawwas and colleagues wrote. “Future studies with a larger sample size are needed to confirm these findings.”
This study is the most thorough comparison to date of the efficacy and safety of apixaban and rivaroxaban, Corinne Frere, MD, PhD, of the department of hematology at Pitié-Salpêtrière Hospital, and Dominique Farge, MD, PhD, professor of internal medicine and vascular disease at Paris Diderot University, Saint-Louis Hospital, wrote in an accompanying editorial.
“The results indicate, for the first time, that apixaban seems to be more effective than rivaroxaban in preventing recurrent VTE, contributing to the resolution of an important clinical question that has yet to be addressed by a randomized controlled trial,” Frere and Farge wrote. “Despite the study limitations... the large sample size and thorough methodology allowed for collection of a large body of data.” – by John DeRosier
Disclosures: The researchers and editorial authors report no relevant financial disclosures.