Idarucizumab (Praxbind) Formulary Review

Idarucizumab (Praxbind), a humanized monoclonal antibody fragment was granted accelerated approval from the Food and Drug Administration in October 2015 as the first agent to reverse the effects of a novel oral anticoagulant. The drug is indicated for dabigatran reversal in patients requiring emergency surgery/urgent procedures or with life-threatening or uncontrolled bleeding. In a randomized study with healthy volunteers, compared with placebo, idarucizumab reduced the clotting times for all tests assays (assessed pre-, end of-, and 24 hours after infusion), while the results for the placebo group remained unchanged. Another randomized clinical trial assessed the safety and efficacy of idarucizumab in patients with either overt bleeding or undergoing emergency surgery where hemostasis was required. This study is ongoing, but preliminary results showed reversal efficacy demonstrated a reasonable safety profile from the time of the infusion to 90 days after. The wholesale acquisition cost of two 2.5 g vials of idarucizumab is currently $3482.50. To treat 10 or 20 patients per year with a single 5 g dose is estimated to cost $34,825 and $69,650, respectively. In the clinical trial described above, approximately 20% of patients required a second dose, which would further increase the cost of use. In this formulary review for a health system's pharmacy and therapeutics committee, idarucizumab clinical trials and medication package insert were summarized and, after consulting with clinical experts from our institutions, practical recommendations for use were generated to ensure appropriate and safe use of this agent.