HEMLIBRA

What it is

Hemlibra is a humanised monoclonal modified IgG4 antibody with a bispecific antibody structure bridging factor IXa and factor X produced by recombinant DNA technology in Chinese hamster ovary cells. Emicizumab bridges activated factor IX and factor X to restore the function of missing activated factor VIII that is needed for effective haemostasis. It is supplied as a solution for subcutaneous injection in single-use colourless glass vials.

Approved indications

— Routine prophylaxis to prevent bleeding or reduce the frequency of bleeding episodes in adult and paediatric patients with haemophilia A (congenital factor VIII deficiency) with or without factor VIII inhibitors.

Dosing overview

The recommended loading dose is 3 mg/kg administered as a subcutaneous injection once weekly for the first 4 weeks, followed by a maintenance dose from Week 5, administered subcutaneously either 1.5 mg/kg once weekly, 3 mg/kg every two weeks, or 6 mg/kg every four weeks. The maintenance dose should be selected based on physician and patient/caregiver dosing regimen preference to support adherence. No dose adjustments are recommended in paediatric patients. No dose adjustments are recommended in patients aged 65 years or over, patients with renal impairment, or patients with hepatic impairment.

Key safety warnings

Cases of thrombotic microangiopathy and thrombotic events were reported when on average a cumulative amount of greater than 100 U/kg/24 hours of activated prothrombin complex concentrate (aPCC) was administered for 24 hours or more to patients receiving Hemlibra prophylaxis. Patients should be monitored for the development of thrombotic microangiopathy and thrombotic events if aPCC is administered, and aPCC should be discontinued and Hemlibra dosing suspended if symptoms occur. Avoid use of aPCC unless no other treatment options or alternatives are available; if aPCC is indicated, the initial dose should not exceed 50 U/kg. Anti-emicizumab antibodies have been reported in a small number of patients treated with Hemlibra in clinical trials. Most patients found to have anti-emicizumab antibodies did not experience a change in emicizumab plasma concentrations or an increase in bleeding events; however, in uncommon cases, the presence of neutralizing anti-emicizumab antibodies with decreasing emicizumab concentration may be associated with loss of efficacy. Injection site reactions were reported very commonly (20%) from clinical trials. All injection site reactions observed were reported as non-serious and mild to moderate in intensity, with 95% resolving without treatment. The commonly reported symptoms were injection site erythema (11%), injection site pain (4%) and injection site pruritis (3%).

Contraindications

Hemlibra is contraindicated in patients with known hypersensitivity to emicizumab or to any of the excipients, or to patients with known hypersensitivity to hamster-derived proteins.

PBS listing

No PBS listing information is provided in the source documents.

Regulatory history

Hemlibra emicizumab was first listed on the ARTG on 23 February 2018, with four registered variants: 30 mg/1 mL, 60 mg/0.4 mL, 105 mg/0.7 mL, and 150 mg/1 mL solutions for injection.