Idarucizumab (Praxbind) has been granted Food and Drug Administration approval under the FDA’s accelerated approval programme for use in patients who are taking the anticoagulant dabigatran (Pradaxa. Boehringer Ingelheim), and need to reverse its blood-thinning effects during emergency situations. Idarucizumab is the first reversal agent approved specifically for dabigatran and works by binding to the drug compound to neutralise its effect. Praxbind solution is for intravenous injection.
Dabigatran was FDA approved in 2010 to prevent stroke and systemic blood clot in patients with atrial fibrillation, as well as for the treatment of pulmonary embolism and deep vein thrombosis.
“The anticoagulant effects of Pradaxa are important and life-saving for some patients, but there are situations where reversal of the drug’s effects is medically necessary,” says Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Today’s approval offers the medical community an important tool for managing patients taking Pradaxa in emergency or life-threatening situations when bleeding cannot be controlled.”
The safety and effectiveness of idarucizumab were studied in three trials involving a total of 283 healthy volunteers taking dabigatran. In the healthy volunteers who were given idarucizumab, there was an immediate reduction in the amount of dabigatran in participants’ blood (measured as unbound dabigatran plasma concentration) that lasted for a period of at least 24 hours. In this study, the most common side effect from use of idarucizumab was headache.
Another trial included 123 patients taking dabigatran who received idarucizumab due to uncontrolled bleeding or because they required emergency surgery. In this ongoing trial, based on laboratory testing, the anticoagulant effect of dabigatran was fully reversed in 89% of patients within four hours of receiving idarucizumab. In this patient trial, the most common side effects were low potassium (hypokalemia), confusion, constipation, fever and pneumonia.
Reversing the effect of dabigatran exposes patients to the risk of blood clots and stroke from their underlying disease (such as atrial fibrillation). The idarucizumab labelling recommends patients resume their anticoagulant therapy as soon as medically appropriate, as determined by their health care provider.
Idarucizumab was approved under the FDA’s accelerated approval programme, which allows the agency to approve drugs for serious conditions that fill an unmet medical need based on an effect on a surrogate or an intermediate clinical endpoint that is reasonably likely to predict a clinical benefit to patients. The programme is designed to provide patients with earlier access to promising new drugs, but the company will be required to submit additional clinical information after approval to confirm the drug’s clinical benefit.