Study Halted When Xarelto Shown to Cause More Bleeding Than Aspirin

Researchers have stopped a study on Xarelto’s (rivaroxaban) safety and efficacy early due to “futility,” according to a press release from pharmaceutical manufacturers Bayer and Janssen Research & Development LLC. The Phase III NAVIGATE ESUS study compared Xarelto and aspirin in patients who had recently had an embolic stroke. Both medications are prescribed to help “thin” the blood and to reduce the risk of a future blood clot.
The study was halted based on the recommendation of the Independent Data Monitoring Committee (IDMC) because the trial showed that both medications had comparable efficacy at reducing the risk of a second stroke, but Xarelto increased the risk of bleeding to a greater extent than aspirin did.

Study Compares Treatments in Patients Who Suffered an Embolic Stroke

Currently, Xarelto is FDA-approved to prevent blood clots after joint-replacement surgery, reduce the risk of pulmonary embolism in patients with deep vein thrombosis (DVT), and reduce risk of stroke in those with non-valvular atrial fibrillation, which is a type of irregular heartbeat.
This Phase III study was designed to evaluate the safety and efficacy of Xarelto for the prevention of blood clots and second strokes in patients who had recently suffered from an embolic stroke.
An embolic stroke is caused by a blood clot in one of the arteries to the brain. This blood clot doesn’t necessarily form there.  Rather, they frequently start somewhere else in the body—usually the heart—and then break free and travel to the brain. Common causes of this type of stroke include atrial fibrillation and carotid artery stenosis (narrowing of the carotid arteries in the neck).
The NAVIGATE ESUS involved about 7,200 patients from 459 sites across 31 countries around the world. The patients were randomly assigned to receive either 15 mg of Xarelto or 100 mg of aspirin once daily. They were then evaluated to see how effective the treatments were, and if they caused any major bleeding.

Researchers Find that Xarelto No More Effective than Aspirin, Yet Riskier

Researchers compared Xarelto to the standard treatment, aspirin, in the hopes of finding that Xarelto was more effective. Through the course of the study, however, that both aspirin and Xarelto were effective at helping to reduce risk of stroke, but Xarelto increased risk of excessive bleeding compared to aspirin.
The trial showed “comparable efficacy between rivaroxaban and the standard of care, aspirin,” Janssen stated in its press release, “and little chance of rivaroxaban showing an overall benefit versus aspirin if the study were to be completed.”
A complete analysis of the study is expected in 2018.