FROM 2017 ISTH CONGRESS
One IV 5-g dose of idarucizumab completely, rapidly, and safely reversed the anticoagulant effect of dabigatran, according to final results for 503 patients in the multicenter, prospective, open-label, uncontrolled RE-VERSE AD study.
Uncontrolled bleeding stopped a median of 2.5 hours after 134 patients received idarucizumab. In a separate group of 202 patients, 197 were able to undergo urgent procedures after a median of 1.6 hours, Charles V. Pollack Jr., MD, and his associates reported at the International Society on Thrombosis and Haemostasis congress. The report was simultaneously published in the New England Journal of Medicine.
The study uncovered no serious safety signals, and rates of thrombosis were 4.8% and 6.8% at 30 and 90 days, respectively, which resembled other reports of these patient populations (N Engl J Med. 2017 Jul 11. doi: 10.1056/NEJMoa1707278).
Idarucizumab was specifically developed to reverse the anticoagulant effect of dabigatran. Many countries have already licensed the humanized monoclonal antibody fragment based on interim results for the first 90 patients enrolled in the Reversal Effects of Idarucizumab on Active Dabigatran ( RE-VERSE AD ) study (NCT02104947), noted Dr. Pollack, of Thomas Jefferson University, Philadelphia.
The final RE-VERSE AD cohort included 301 patients with uncontrolled gastrointestinal, intracranial, or trauma-related bleeding and 202 patients who needed urgent procedures. Participants from both groups typically were white, in their late 70s (age range, 21-96 years), and receiving 110 mg (75-150 mg) dabigatran twice daily. The primary endpoint was maximum percentage reversal within 4 hours after patients received idarucizumab, based on diluted thrombin time and ecarin clotting time.
The median maximum percentage reversal of dabigatran was 100% (95% confidence interval, 100% to 100%) in more than 98% of patients, and the effect usually lasted 24 hours. Among patients who underwent procedures, intraprocedural hemostasis was considered normal in 93% of cases, mildly abnormal in 5% of cases, and moderately abnormal in 2% of cases, the researchers noted. Seven patients received another dose of idarucizumab after developing recurrent or postoperative bleeding.
A total of 24 patients had an adjudicated thrombotic event within 30 days after receiving idarucizumab. These events included pulmonary embolism, systemic embolism, ischemic stroke, deep vein thrombosis, and myocardial infarction. The fact that many patients did not restart anticoagulation could have contributed to these thrombotic events, the researchers asserted. They noted that idarucizumab had no procoagulant activity in studies of animals and healthy human volunteers.
About 19% of patients in both groups died within 90 days. “Patients enrolled in this study were elderly, had numerous coexisting conditions, and presented with serious index events, such as intracranial hemorrhage, multiple trauma, sepsis, acute abdomen, or open fracture,” the investigators wrote. “Most of the deaths that occurred within 5 days after enrollment appeared to be related to the severity of the index event or to coexisting conditions, such as respiratory failure or multiple organ failure, whereas deaths that occurred after 30 days were more likely to be independent events or related to coexisting conditions.”
Boehringer Ingelheim Pharmaceuticals provided funding. Dr. Pollack disclosed grant support from Boehringer Ingelheim during the course of the study and ties to Daiichi Sankyo, Portola, CSL Behring, Bristol-Myers Squibb/Pfizer, Janssen Pharma, and AstraZeneca. Eighteen coinvestigators also disclosed ties to Boehringer Ingelheim and a number of other pharmaceutical companies. Two coinvestigators had no relevant financial disclosures.