The reversal agent for dabigatran (Idarucizumab, Praxbind) can quickly halt the effect of the novel oral anticoagulant in patients with life threatening bleeding or in those who need urgent surgery, the final data from REVERSE-AD reveals.

The findings confirm the results of an interim analysis that saw the reversal agent gain regulatory approval last year.

Now the final analysis presented overnight at the International Society on Thrombosis and Haemostasis (ISTH) 26th Biennial Congress in Berlin, Germany and simultaneously published in the New England Journal of Medicine has also shed light on some important practical aspects of the reversal agent.

A single 5-g dose of idarucizumab was enough to completely reverse the effect of dabigatran within minutes in 98% of the 503 patients involved in the study and reversal was maintained for 24 hours in most patients.

Thrombotic events observed in the study – 4.8% at 30 days and 6.8% at 90 days – occurred within 72 hours of the reversal agent being administered.

The authors noted that the mortality rates reported in RE-VERSE AD – 18.8% in patients treated for serious bleeds and 18.9% in patients who underwent urgent surgery – was lower than in patients taking warfarin (intracranial haemorrhage, 50%; emergency intervention 30% mortality rate).

Some 114 patients had a recurrent elevated clotting time between 12 and 24 hours after treatment, which the researchers noted was likely to have been caused by a redistribution of unbound dabigatran.

The fact that participants were not required to have a baseline coagulation test available before being administered the reversal agent supported its use in patients with little or no circulating dabigatran, the study authors added.

However, they advised that only those with new-onset or recurrent bleeding should be considered for a second dose of idarucizumab.

Study co-author Dr Amanda Hugman, a haematologist at St George Hospital, Sydney, said the ability to switch off the anticoagulant effect of dabigatran in minutes was a significant step forward in anticoagulation care.

“Emergencies or accidents can happen to anyone at any time. Knowing that the anticoagulant effect of [dabigatran] can be rapidly halted in emergency situations will be reassuring for doctors and patients alike,” she said.