In a new study published in the New England Journal of Medicine, researchers evaluated 352 patients (mean age 77 years) with acute major bleeding within 18 hours after administration of a bolus of andexanet, followed by a 2-hour infusion. Bleeding was predominantly intracranial (in 227 patients [64%]) or gastrointestinal (in 90 patients [26%]). For those anticoagulated with apixaban, the median anti–factor Xa activity decreased from 149.7 ng/mL at baseline to 11.1 ng/mLafter the bolus, whilst for those who had received rivaroxaban, the median value decreased from 211.8 ng/mL to 14.2 ng/mL. Excellent or good haemostasis was achieved for 204 of 249 patients (82%) who could be evaluated. Within 30 days, 49 patients had died (14%) and 34 (10%) had a thrombotic event Th reduction in anti–factor Xa activity was not predictive of haemostatic efficacy overall but was modestly predictive in patients with intracranial hemorrhage. Treatment with andexanet markedly reduced anti–factor Xa activity, and 82% of patients had excellent or good hemostatic efficacy at 12 hours, as adjudicated according to pre-specified criteria.