The surprise decision was announced yesterday by Portola Pharmaceuticals.
The FDA asked Portola for more information on manufacturing and data to support the inclusion of Savaysa and Lovenox on the label.
The company sought approval for AndexXa after two Phase III clinical trials showed that it reversed Eliquis by 93% and Xarelto by 92% for two hours in healthy patients.
Factor Xa inhibitors are a new class of blood-thinning drugs that have only been on the market since 2011. Because none of them have reversal agents, AndexXa is an FDA-designated “breakthrough” drug.
Factor Xa inhibitors include:
- Xarelto (rivaroxaban)
- Eliquis (apixaban)
- Savaysa (enoxaban)
- Lovenox (enoxaparin)
Portola said 1-4% of patients on Factor Xa inhibitors experience major bleeding, and another 1% need emergency surgery. Without a way to de-activate their blood-thinning medication, doctors may struggle to stop bleeding or delay a life-saving surgery.
In the European Union alone, an estimated 73,000 patients on these drugs will be hospitalized for major bleeding or require urgent surgery.
The manufacturers of Xarelto, Bayer and Janssen Pharmaceuticals, are facing about 8,000 lawsuits involving severe injuries and deaths from uncontrollable bleeding. They are accused of downplaying the risk of bleeding to promote Xarelto as superior to warfarin, a drug that is easily de-activated with a dose of Vitamin K.