Janssen Research & Development, LLC and its development partner Bayer have announced the phase III NAVIGATE ESUS study, evaluating the efficacy and safety of Xarelto (rivaroxaban) for the secondary prevention of stroke and systemic embolism in patients with a recent embolic stroke of undetermined source (ESUS), is stopping early for futility. This decision is based on the recommendation of the study’s Independent Data Monitoring Committee (IDMC) as the trial showed comparable efficacy between rivaroxaban and the standard of care, aspirin, and little chance of rivaroxaban showing an overall benefit versus aspirin if the study were to be completed. While bleeding rates were very low overall and within the expected range, an increase in bleeding was observed in the rivaroxaban arm compared to aspirin.

ESUS refers to patients with embolic stroke of unknown origin in whom common causes such as atrial fibrillation and carotid artery stenosis have been excluded. It is estimated to affect approximately 500,000 people in the United States annually.

“Xarelto is a highly effective anticoagulant for patients at risk for stroke from atrial fibrillation, as well as for the prevention and treatment of clots in a variety of approved indications,” said Paul Burton, MD, PhD, FACC, vice president, Medical Affairs, Janssen. “Results from ROCKET AF and emerging real-world data continue to show the positive benefit of Xarelto in preventing cardiovascular events, including stroke.”

The phase III NAVIGATE ESUS trial enrolled approximately 7,200 patients from 459 sites across 31 countries worldwide. In the study, patients were randomized to receive either rivaroxaban 15 mg once daily or aspirin 100 mg once daily alone. The primary efficacy endpoint was a composite of stroke and systemic embolism; the primary safety endpoint was major bleeding. A complete data analysis is expected to be presented in 2018.