Researchers from the prestigious Brigham and Women’s Hospital in Boston have recently published details of their initial experience of using Andexanet alfa (the first FDA approved targeted agent for the reversal of the effects of oral factor Xa inhibitors (Xai). The drug is a recombinant factor Xa that neutralizes unbound Xai. The criteria for use at the hospital are critical life‐threatening bleeding and rivaroxaban/apixaban used less than 18 hours before presentation. Critical life‐threatening bleeding was defined as bleeding that causes haemodynamic compromise, threatens a vital organ, or may result in disability, and which not respond to conventional measures.

As of October 8, 2018, the drug had been administered to 15 patients, 14 with intracranial haemorrhage. The mean age of patients was 82 years and 3/4 had been anticoagulated for atrial fibrillation. 7 of the treated patients were taking apixaban and the remainder were anticoagulated with rivaroxaban. 7 received prothrombin complex concentrate (PCC) prior to transfer to admission to the hospital. The time from order placement to bedside‐delivery averaged 43 minutes; time from order to bolus administration averaged 66 minutes. Although 7 patients had combined use of PCC and andexanet alfa, thrombotic events were not observed. Inpatient mortality was 40%. Five patients died within 4 days of presentation as a result of initial bleeds, one patient died after 13 days from infection.

The authors describe various challenges – these included limited availability via the early supply program, the need to determine use in patients who received PCC prior to transfer; the lack of approved anti‐Xa assays for assessment of anticoagulant levels and delays associated with drug preparation time. Read more here