Chicago—Brain bleed is among the greatest concerns with novel oral anticoagulants (NOACs), such as dabigatran.
Now, a presentation at the International Stroke Conference 2016 in Los Angeles reports that a newly approved medication reverses the blood-thinning effects of dabigatran in patients suffering an intracranial hemorrhage, potentially limiting the extent of bleeding.
Idarucizumab, marketed as Praxbind, is an antibody that chemically binds and neutralizes the blood-thinning effects of dabigatran.
Lead author Richard A. Bernstein, MD, PhD, director of the stroke program at Northwestern Memorial Hospital in Chicago, told the conference that an interim analysis of the first 90 patients in the RE-VERSE AD (REVERSal Effects of idarucizumab in patients on Active Dabigatran) trial indicated that idarucizumab effectively reversed dabigatran's anticoagulant effects.
Of the 90 patients, 18 had intracranial hemorrhage—11 men and seven women, average age 79.
The presentation noted that both doses of dabigatran—110 mg and 150 mg bid—were associated with a significantly lower annualized rate of intracranial hemorrhage than warfarin, 0.23%, 0.32%, and 0.76%, respectively, but that the brain bleed mortality rate remains high.
For the study, patients presenting with ICH were given intravenous idarucizumab 5 g as two 2.5-g bolus infusions administered no more than 15 minutes apart. The primary endpoint for the trial was the maximum reversal of the anticoagulant effect of dabigatran, based on central laboratory determination of the dilute thrombin time or ecarin clotting time.
Blood tests revealed that dabigatran’s blood-thinning effect was 100% reversed in all 18 patients with brain bleed, according to the presentation.
“This is definitely good news,” Bernstein said. “Idarucizumab rapidly and completely reverses the effect of dabigatran in patients with brain hemorrhage. Once the dabigatran is reversed, we can focus on taking care of the patient without worrying about the blood thinner.”
Idarucizumab was approved by the FDA in October 2015 as the first medicine designed to reverse dabigatran.
Prior to idarucizumab’s availability, dabigatran patients who needed emergency surgery were given purified clotting factors, which carry the risk of dangerous blood clots, according to the preliminary study. That does not appear to be the case with the newly approved drug, according to Bernstein, who added, “Idarucizumab gets rid of the dabigatran, but doesn't seem to carry with it any tendency to increase clotting. This should make perioperative management easier and safer.”
The availability of a reversal agent could increase use of the NOACs, he said, explaining, “The biggest problem we face in preventing stroke in patients with atrial fibrillation is that almost half of patients don’t take any blood thinner at all. I see the biggest impact of idarucizumab as providing reassurance to patients that if bleeding while taking dabigatran does occur, we can quickly reverse the dabigatran. This reassurance could lead to more strokes prevented by increasing the use of an effective blood thinner.”
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