Extended Anticoagulant Treatment with Full- or Reduced-Dose Apixaban in Patients with Cancer-Associated Venous Thromboembolism: Rationale and Design of the API-CAT Study

Abstract

Cancer-associated thrombosis (CAT) is associated with a high risk of recurrent venous thromboembolic events (VTE) that require extended anticoagulation in patients with active cancer, putting them at risk of bleeding.The aim of the API-CAT study (NCT03692065) is to assess whether a reduced-dose regimen of apixaban (2.5 mg twice daily [bid]) is non-inferior to a full-dose regimen of apixaban (5 mg bid) for the prevention of recurrent VTE in patients with active cancer who have completed ≥6 months of anticoagulant therapy for a documented index event of proximal deep-vein thrombosis and/or pulmonary embolism.APICAT is an international, randomized, parallel-group, double-blind, non-inferiority trial with blinded adjudication of outcome events. Consecutive patients are randomized to receive apixaban 2.5 mg or 5 mg bid for 12 months. The primary efficacy outcome is a composite of recurrent symptomatic or incidental VTE during the treatment period. The principal safety endpoint is clinically relevant bleeding, defined as a composite of major bleeding or non-major clinically relevant bleeding. Assuming a 12-month incidence of the primary outcome of 4% with apixaban and an upper limit of the 2-sided 95% confidence interval of the hazard ratio <2.0, 1722 patients will be randomized,assuming an up to 10% loss in total patient-years (β = 80%; α 1-sided = 0.025). This trialhas the potential to demonstrate that a regimen of extended treatment for patients with CAT beyond an initial 6 months, with a reduced apixaban dose,has an acceptable risk of recurrent VTE recurrence and decreases the risk of bleeding. Received: 27 May 2021 Accepted after revision: 08 July 2021 Publication Date: 17 September 2021 (online) © 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/). Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany