Rocket AF: rivaroxaban shows efficacy

While warfarin has served as the oral anticoagulant of choice for some decades, a variety of new agents that hold several advantages (fewer interactions with other drugs, no need for therapeutic drug monitoring and simpler dosing regimen) are now in late-stage development.

The latest of these warfarin competitors to complete Phase III trials is the factor Xa inhibitor rivaroxaban. In the double-blind, double-dummy ROCKET AF trial, the investigators randomly assigned 14 264 patients with non-valvular atrial fibrillation—who were at moderate to high risk of stroke—to receive either rivaroxaban (at a daily dose of 20 mg) or dose-adjusted warfarin. Blinding was maintained through encrypted INR monitoring for all participants, allowing for sham adjustment of placebo for those in the rivaroxaban arm. The primary clinical end point was stroke or systemic embolism, and the principal safety end point was a composite of major and non-major clinically relevant bleeding. The study was powered to demonstrate non-inferiority of rivaroxaban, and the median follow-up was 2 years. The primary end point occurred in 188 patients in the rivaroxaban group (1.7% per year) and in 241 patients in the warfarin group (2.2% per year) (HR, 0.79; 95% CI 0.66 to 0.96; p<0.001 for non-inferiority). In the safety analysis, bleeding occurred in 1475 patients in the rivaroxaban group (14.9% per year) and in 1449 patients in the warfarin group (14.5% per year) (HR, 1.03; 95% CI 0.96 to 1.11; p=0.44). However, …