Andexanet Bolus, Infusion Cuts Anti-Factor Xa Activity
Findings in patients with acute major bleeding associated with factor Xa inhibitors
TUESDAY, Aug. 30, 2016 (HealthDay News) -- For acute major bleeding within 18 hours after factor Xa inhibitor administration, a bolus and infusion of andexanet alfa (andexanet) reduces factor Xa activity, according to a study published online Aug. 30 in the New England Journal of Medicine. The research was published to coincide with the annual European Society of Cardiology Congress, held from Aug. 27 to 31 in Rome.
Stuart J. Connolly, M.D., from McMaster University in Hamilton, Canada, and colleagues conducted a multicenter trial involving 67 patients with acute major bleeding within 18 hours after administration of a factor Xa inhibitor. The patients all received a bolus of andexanet followed by a two-hour infusion.
The researchers found that among patients receiving rivaroxaban and apixaban, the median anti-factor Xa activity decreased by 89 and 93 percent, respectively, from baseline after the bolus administration. During the two-hour infusion these levels remained similar. There was a relative decrease from baseline of 39 and 30 percent in the measure of anti-factor Xa activity at four hours after the end of the infusion for patients receiving rivaroxaban and apixaban, respectively. Clinical hemostasis was excellent or good at 12 hours after andexanet infusion in 79 percent of patients in the efficacy analysis.
"An initial bolus and subsequent two-hour infusion of andexanet substantially reduced anti-factor Xa activity in patients with acute major bleeding associated with factor Xa inhibitors, with effective hemostasis occurring in 79 percent," the authors write.
The study was funded by Portola Pharmaceuticals, the developer of andexanet alfa.