October 6, 2017
By Alex Keown, BioSpace.com Breaking News Staff
BERLIN – Bayer and its developmental partner Janssen Research & Development are calling it quits on a Phase III stroke prevention study. An analysis of interim data indicated that the blockbuster anti-clotting drug Xarelto was not as beneficial on its own in comparison to a regimen of low-dose aspirin for that patient population.
Researchers were looking at expanding the use of the blood-thinner Xarelto as a preventative for a second stroke and systemic embolism in patients who experienced a recent embolic stroke of undetermined source (ESUS). Following a review of interim data the Independent Monitoring Committee determined that Xarelto on its own was not as potent as a low-dose of aspirin. In its announcement, Bayer said there was “very little chance” of Xarelto showing an overall benefit if the trial continued.
ESUS refers to patients with embolic stroke documented by neuroimaging for which the cause remains unidentified despite thorough investigations attempting to rule out established cardiac and vascular sources. It does not include patients with atrial fibrillation or established atherosclerotic disease, Bayer said. Joerg Moeller, head of development at Bayer, said there are few treatment options for patients with ESUS. He said the role of anticoagulants as a treatment option remain unclear. The research team will analyze the data from the late-stage trial to determine its implications, he added. A complete data analysis is expected to be presented at an upcoming medical meeting in 2018. Moeller said Bayer remains “committed to continuing the extensive investigation of rivaroxaban for patients at risk of deadly blood clots.”
The trial included more than 7,000 patients who received a once-daily dose of either 15 mg of Xarelto or 100 mg of aspirin. The primary efficacy endpoint was a composite of stroke (ischemic, hemorrhagic and undefined stroke, transient ischemic attack with positive neuroimaging) and systemic embolism.
In addition to its failure to be as efficacious as the low-dose of aspirin, researchers noted some safety concerns as well. Observers reported that bleeding rates were higher in patients taking Xarelto in comparison to those using the aspirin regimen. Bleeding rates were the primary safety endpoints of the trial.
Both Janssen and Bayer have been taken to court over safety concerns with Xarelto. Lawsuits filed against both companies claim the companies failed to warn patients and physicians of increased risks of fatal internal bleeding when using the drug. There have been more than 5,000 lawsuits filed by patients and their families claiming harm from taking Xarelto. Of those lawsuits, 500 involved patient deaths, according to a 2016 report in The New York Times.
Xarelto has been approved for seven indications, including the treatment of pulmonary embolisms in adults and the treatment of deep vein thrombosis in adults.
