Observational Studies in Cancer Associated Thrombosis for Rivaroxaban - United States Cohort

Patients with active cancer are \~5-fold more likely to develop a venous thromboembolism (VTE) than those without. When VTE occurs, cancer patients carry an up to a 3-fold higher rate of thrombosis recurrence and \~twice the risk of bleeding during anticoagulation. Therefore, it is critical to utilize anticoagulants that optimize efficacy while minimizing bleeding risk when treating cancer-associated thrombosis (CAT). Guidelines list direct-acting oral anticoagulants (DOACs) as an alternative to low molecular-weight heparin (LMWH) for treatment of CAT. The strength-of-recommendation for DOACs is based on data from multiple randomized controlled trials (RCTs) comparing them to LMWHs to treat CAT, with results suggesting DOACs may reduce thrombosis risk but with potentially more frequent bleeding (particularly in those with certain gastrointestinal and genitourinary cancers). Observational studies evaluating DOACs for CAT treatment have been published, but these studies have been either single-arm, evaluated cancer subtypes not recommended for DOAC treatment, were of limited sample size and/or employed heterogeneous definitions of active cancer. We seek to evaluate the effectiveness and safety of rivaroxaban versus LMWH for CAT treatment in active cancer patients using a large de-identified electronic health record database. Retrospective cohort analysis using US Optum® De-Identified EHR data. We will use Optum EHR (electronic health records) data from November January 1, 2012 through latest available data (currently September 2020).