PRAXBIND

What it is

PRAXBIND is idarucizumab, a solution for injection/infusion supplied as vials containing 2.5 g of idarucizumab (50 mg/mL). Idarucizumab is a humanised monoclonal antibody fragment (Fab) that binds to dabigatran with very high affinity, approximately 300-fold higher than the binding affinity of dabigatran for thrombin at physiological pH. It is a specific reversal agent for dabigatran.

Approved indications

PRAXBIND is indicated in patients treated with dabigatran etexilate (PRADAXA) when rapid reversal of the anticoagulant effects of dabigatran is required for: — Emergency surgery or urgent procedures — Life-threatening or uncontrolled bleeding

Dosing overview

The recommended dose of PRAXBIND is 5 g (2x2.5 g/50 mL). PRAXBIND is administered intravenously, as two consecutive infusions over 5 to 10 minutes each or as a bolus injection. A second 5 g dose of PRAXBIND may be considered in patients with recurrence of clinically relevant bleeding together with prolonged clotting times, or in patients who require a second emergency surgery or urgent procedure and have prolonged clotting times. The safety and efficacy of repeat treatment with PRAXBIND have not been established.

Key safety warnings

Patients being treated with dabigatran have underlying disease states that predispose them to thromboembolic events. Reversal of dabigatran therapy exposes patients to the thrombotic risk of their underlying disease. To reduce this risk, resumption of anticoagulant therapy should be considered as soon as medically appropriate. The risk of using PRAXBIND in patients with known hypersensitivity to idarucizumab or to any of the excipients needs to be weighed cautiously against the potential benefit of such an emergency treatment. If an anaphylactic reaction or other serious allergic reaction occurs, administration of PRAXBIND should be discontinued immediately and appropriate therapy initiated. The recommended dose of PRAXBIND contains 4 g sorbitol as an excipient. In patients with hereditary fructose intolerance, parenteral administration of sorbitol has been associated with reports of hypoglycaemia, hypophosphatemia, metabolic acidosis, increase in uric acid, acute liver failure with breakdown of excretory and synthetic function, and death. Therefore, in patients with hereditary fructose intolerance the risk of treatment with PRAXBIND must be weighed against the potential benefit of such an emergency treatment. PRAXBIND causes transient proteinuria as a physiologic reaction to renal protein overflow after bolus or short-term application of 5 g idarucizumab intravenously. The transient proteinuria is not indicative of renal damage, which should be taken into account for urine testing.

Contraindications

There are no contraindications to PRAXBIND.

Regulatory history

PRAXBIND (idarucizumab 50 mg/ml solution for injection/infusion vial) was first listed on the Australian Register of Therapeutic Goods on 11 May 2016. In November 2014, the PBAC recommended PRAXBIND for the reversal of dabigatran anticoagulant effects in emergency situations.