Bleeding risk spikes for Astellas's PhII anticoagulant

Just days after Pfizer ($PFE) and Bristol-Myers Squibb ($BMY) offered up stellar safety and efficacy data on their anti-clotting therapy Eliquis, researchers revealed that Astellas's oral anticoagulant candidate in the same Factor Xa inhibitor class significantly raised the risk of bleeding among patients with acute coronary syndrome in a mid-stage trial. Those results mirror the dangers that investigators found when they tried Eliquis on a similar patient group. Reporting from Paris, Reuters' Ben Hirschler also spread the word that darexaban failed to demonstrate efficacy among the 1,279 patients in the study-- even though the trial wasn't big enough to provide any definitive data on that score.

Investigators have been hungering to show that a Factor Xa inhibitor can safely treat patients in the ACS group. But researchers concluded that darexaban doubled or even quadrupled the risk of bleeding. That still leaves the whole atrial fibrillation crowd, which Astellas has in its sights, along with reducing the risk of blood clots after orthopedic surgery. And researchers insist there's still reason to hope for better results in ACS.

"I think we have a series of mixed signals. It is probably a little too soon to forgo the idea of adding anticoagulants to anti-platelet therapy," Dr. Gabriel Steg of the Hospital Bichat in Paris told reporters at the European Society of Cardiology, according to the Reuters story. Dr. David Holmes of the Mayo Clinic said trying a lower dose of the drug may yet work.

If darexaban can make it to the marketplace it will face plenty of major league competition. The prospective arrival of Eliquis would come after approvals for Pradaxa and Xarelto.

- here's the Reuters story from Ben Hirschler