Pradaxa antidote enters Phase III

Boehringer Ingelheim has kicked off US Phase-III testing of its antidote to its prescription blood thinner Pradaxa (dabigatran). Testing has already started abroad, and the company said in a statement that the Re-verse AD trial is the first trial to investigate an antidote in patients “currently taking a newer oral anticoagulant.”

Boehringer has been on the defense about the drug for some time over bleeding concerns, even though the FDA said in November 2013 that the drug did not put patients at an increased risk for bleeding. The regulator reiterated this stance with a study released this month that indicated that although Pradaxa did put patients at an increased risk for “major gastrointestinal hemorrhage, compared to warfarin in patients with non-valvular atrial fibrillation,” that it also reduced the risk of ischemic stroke by 20%, reduced the risk of intracranial hemorrhage by 66% and showed no difference in major hemorrhage compared to warfarin.

The image problem: JAMA Internal Medicine published its own findings, the very same day as the FDA, and JAMA's authors were not so clear-cut, writing that it is “unclear” if Pradaxa “is associated with higher risk of bleeding than warfarin in real-world clinical practice,” while at the same time saying they found a higher bleeding risk compared to warfarin as a whole, and found the “risk of major bleeding among dabigatran users was especially high for African Americans and patients with chronic kidney disease.”

The FDA granted the antidote Breakthrough Designation status in June.