Apixaban reduces bleeding in acute venous thromboembolism (VTE) by more than 50%, compared to rivaroxaban, data presented at the ISTH 2025 congress shows.
Results from the COBRRA trial showed that 3% of acute VTE patients given apixaban experienced a clinically relevant bleed during three months of treatment, compared to 7% of those given rivaroxaban.
Major bleeds and clinically relevant non-major bleeds were also significantly less common among patients treated with apixaban, although rates of recurrent VTE and death were similar for both direct oral anticoagulants (DOACs).
“For most patients with acute VTE planned to receive a DOAC, apixaban should be considered the treatment of choice,” said Dr Lana Castellucci, Associate Professor in the Faculty of Medicine at the University of Ottawa, Canada, when presenting the data as part of a late breakthrough session at ISTH 2025 in Washington D.C.
“Any inconvenience of twice daily apixaban dosing compared to once daily rivaroxaban is offset by the more than 50% reduction in the risk of bleeding,” she added.
The open-label COBRRA (Comparison of Bleeding Risk between Rivaroxaban and Apixaban for acute VTE) trial took place at 32 sites across Canada, Australia and Ireland, and aimed to address the lack of head-to-head trials between DOACs that prevent guidelines recommending a specific drug for acute VTE.
The study recruited patients with acute symptomatic proximal lower extremity deep vein thrombosis, or segmental or greater pulmonary embolism, and excluded those who had undergone more than 72 hours of therapeutic anticoagulation, had a creatine clearance rate of less than 30ml/min, or an active malignancy, or who weighed more than 120kg.
Participants (mean age 58 years, 43% female) were randomised to receive apixaban (n=1345; 10mg twice daily for seven days then 5mg twice daily thereafter), or rivaroxaban (n=1355; 15mg twice daily for 21 days then 20mg daily thereafter).
After three months of treatment, 44 patients (3%) given apixaban experienced clinically relevant bleeding, a significantly lower proportion than the 97 patients (7%) treated with rivaroxaban (OR 0.44, p<0.00001).
Major bleeding and clinically relevant non-major bleeding were also significantly less common among patients given apixaban compared to those given rivaroxaban (0.4% vs 2.3%, p<0.00001; 3% vs 5%, p<0.005, respectively).
Rates of recurrent VTE were similar across both groups (1% vs 1%), and one death (0.1%) occurred in the apixaban group compared to four deaths (0.3%) on rivaroxaban.
“This is the first randomised head-to-head comparison trial of apixaban and rivaroxaban for acute VTE treatment,” said Dr Castellucci in her presentation.
“It is important to note that our findings are not generalisable to other clinical settings, including extended-duration VTE secondary prevention, whether at full dose or reduced dose; for patients with cancer-associated acute VTE; and importantly in atrial fibrillation, where we have an ongoing trial,” she added.