Apixaban and rivaroxaban are widely used anticoagulants for treating acute venous thromboembolism, including deep-vein thrombosis and pulmonary embolism. A major question has persisted over their comparative bleeding risks.
The COBRRA trial, led by Lana Castellucci, directly compared the two drugs in 2,760 patients across an international cohort. Participants with acute pulmonary embolism or proximal deep-vein thrombosis were randomly assigned to receive either apixaban or rivaroxaban for three months.
The primary endpoint was clinically relevant bleeding. Results showed 3.3% of apixaban patients experienced such events versus 7.1% on rivaroxaban-a 54% lower relative risk (p<0.001). Non-bleeding serious adverse events were similar between groups.
All-cause mortality was 0.1% with apixaban and 0.3% with rivaroxaban. Researchers noted differing dosing regimens, suggesting future studies isolate drug effects at matched doses.
The findings support apixaban as a safer option regarding bleeding in acute venous thromboembolism treatment.