SESSION TITLE: Outcomes/Quality Control
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Wednesday, October 29, 2014 at 08:45 AM - 10:00 AM
PURPOSE: Acute symptomatic venous thromboembolism (VTE) is a common disorder associated with a substantial risk of recurrence. Short-term treatment with anticoagulants can considerably reduce the risk of VTE recurrence; however some acute VTE patients require extended treatment. Extended treatment of acute VTE patients with each of the new oral anticoagulants (NOACs), dabigatran, rivaroxaban, and apixaban vs. placebo has been shown in phase III trials to be associated with a reduced risk of VTE recurrence. However, the risks of VTE recurrence and major bleeding (MB) relative to placebo treated patients differed among patients treated with the different NOACs in the trials. The purpose of this study was to compare the net clinical benefits (NCB) of extended treatment with NOACs based on RESONATE, EINSTEIN-EXT, and AMPLIFY-EXT trial results.
METHODS: Event rates of recurrent VTE and MB, measured in each original trial as percentage of patients with the corresponding events, among VTE patients during trial periods were obtained from the published clinical trial data. The combinations of rates of recurrent VTE, representing VTE recurrence or VTE-related death and MB were evaluated and defined as the NCB of each NOAC. Additionally, the number of VTE patients needed to be treated (NNT) with each NOAC to avoid one VTE or MB event were determined.
RESULTS: Among patients in the extended VTE NOAC treatment clinical trials, the differences in event rates of recurrent VTE for those treated with dabigatran, rivaroxaban, 2.5mg apixaban, and 5mg apixaban vs. placebo were ‑5.2%, -5.7%, -7.1%, and -7.1% respectively. The differences in event rates of MB for those treated with dabigatran, rivaroxaban, 2.5mg apixaban, and 5mg apixaban vs. placebo were 0.3%, 0.7%, -0.2%, and -0.4% respectively. The NCB improved for all NOAC treated patients, with those treated with apixaban (2.5mg: ‑7.4%, 5mg: -7.4%) having the greatest NCB, followed by those treated with rivaroxaban (-5.1%) and dabigatran (‑4.9%). The NNT with dabigatran, rivaroxaban, 2.5mg apixaban, and 5mg apixaban to avoid one VTE or MB event from the trials were 21, 20, 14, and 13.
CONCLUSIONS: Extended treatment of VTE patients with any of the NOACs was shown to be efficacious for reducing the risk of recurrent VTE in clinical trials. Apixaban may provide the optimal NCB with the lowest NNT to avoid one VTE or MB event.
CLINICAL IMPLICATIONS: How these results translate into real-world outcomes will require further evaluation.
DISCLOSURE: Alpesh Amin: Consultant fee, speaker bureau, advisory committee, etc.: Bristol-Myers Squibb, Consultant fee, speaker bureau, advisory committee, etc.: Pfizer Yonghua Jing: Employee: Bristol-Myers Squibb Jeffrey Trocio: Employee: Pfizer Jay Lin: Employee: Novosys Health Melissa Lingohr-Smith: Employee: Novosys Health John Graham: Employee: Bristol-Myers Squibb
Rivaroxaban is FDA approved for VTE treatment, while dabigatran and apixaban are currently not approved.