Apixaban for the Treatment of Japanese Subjects With Acute Venous Thromboembolism (AMPLIFY-J Study)

BACKGROUND: Anticoagulation is recommended as standard of care for venous thromboembolism (VTE) (pulmonary embolism [PE]/deep vein thrombosis [DVT]), for which unfractionated heparin (UFH) and warfarin are used in Japan. In the multi-regional AMPLIFY study, a fixed-dose regimen of apixaban alone was non-inferior to conventional therapy for treatment of PE/DVT and was associated with significantly fewer bleeding events. METHODS AND RESULTS: Japan phase 3 study (AMPLIFY-J), randomized, active-controlled, open-label study in Japanese subjects with acute PE/DVT, was designed based on AMPLIFY. Key objectives were to investigate safety and efficacy of apixaban in symptomatic PE/DVT subjects during 24-week treatment. UFH/warfarin was used as control treatment. Apixaban was initiated at 10 mg twice daily for 7 days, followed by 5 mg twice daily for 23 weeks. All endpoints and imaging for thrombotic burden were assessed by an event adjudication committee. Eighty subjects were randomized, 33 subjects (41.3%) were aged <65 years. Proportion of major/clinically relevant non-major bleeding was lower in apixaban (7.5%) compared with well-controlled UFH/warfarin (28.2%; median TTR, 70.4%). [corrected]. Recurrent VTE occurred in no subjects in apixaban and in 1 subject in UFH/warfarin. Thrombotic burden results were similar in both groups. Proportions of subjects with adverse events was generally similar in both groups. CONCLUSIONS: Apixaban was well-tolerated and had a favorable safety profile. No clinically important efficacy difference compared with UFH/warfarin was observed.