GAMUNEX

What it is

GAMUNEX is normal immunoglobulin (Human), 10%, for intravenous or subcutaneous administration. One millilitre contains 100 mg of normal immunoglobulin (human) with a purity of at least 98% IgG. The product is supplied in vials ranging from 10 mL (1 g) to 400 mL (40 g). It is produced from plasma of human donors. The solution is clear to opalescent, colourless to pale yellow.

Approved indications

— Primary Immunodeficiency (PI) Diseases, as replacement therapy. — Symptomatic Hypogammaglobulinaemia secondary to underlying disease or treatment, as replacement therapy. — Idiopathic Thrombocytopaenic Purpura (ITP), in patients at high risk of bleeding or prior to surgery to correct the platelet count, as immunomodulation. — Guillain Barré Syndrome (GBS), as immunomodulation. — Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), as immunomodulation. — Kawasaki disease, as immunomodulation.

Dosing overview

GAMUNEX is recommended for intravenous infusion for all indications. It can also be administered by subcutaneous infusion for replacement therapy in primary immunodeficiency indications only.

Key safety warnings

Because GAMUNEX is made from human blood, it may carry a risk of transmitting infectious agents such as viruses. The risk has been reduced by screening plasma donors, testing for current virus infections, and inactivating or removing certain viruses, but such products can still potentially transmit disease and unknown infectious agents may be present. GAMUNEX should be administered only intravenously or subcutaneously. On rare occasions, treatment may cause a precipitous fall in blood pressure and anaphylaxis, even in patients not known to be sensitive to immunoglobulin preparations. Adrenalin and appropriate supportive care should be available. An aseptic meningitis syndrome (AMS) has been reported infrequently in association with intravenous immunoglobulin treatment, usually beginning within several hours to two days of treatment and characterised by severe headache, nuchal rigidity, drowsiness, fever, photophobia, painful eye movements, nausea and vomiting. AMS may occur more frequently with high dose (2 g/kg) and or rapid infusion. Human normal immunoglobulin intravenous products can contain blood group antibodies which may induce in vivo coating of red blood cells and, rarely, haemolysis. Haemolytic anaemia can develop subsequent to GAMUNEX therapy. Recipients should be monitored for clinical signs and symptoms of haemolysis. Thrombotic events have been reported in association with GAMUNEX. This association is assumed to be related to a relative increase in blood viscosity. Caution should be exercised in prescribing GAMUNEX in obese patients and in patients with pre-existing risk factors for thrombotic events such as advanced age, hypertension, diabetes mellitus, history of vascular disease, impaired cardiac output, hypercoagulable conditions, prolonged immobilisation, use of oestrogens, indwelling central vascular catheters, hyperviscosity, severe hypovolaemia and diseases which may increase blood viscosity. Human normal immunoglobulin intravenous products have been reported to be associated with acute renal dysfunction, acute renal failure, acute tubular necrosis, proximal tubular nephropathy, osmotic nephrosis and death. Patients predisposed to acute renal failure include those with pre-existing renal insufficiency, diabetes mellitus, age greater than 65, volume depletion, sepsis, paraproteinaemia, or those who are overweight or receiving known nephrotoxic drugs.

Contraindications

GAMUNEX is contraindicated in individuals with known anaphylactic or severe systemic response to human immunoglobulin or any of the excipients of the product. This applies in particular to individuals with severe, selective IgA deficiencies (serum IgA less than 0.05 g/L) who have known antibodies against IgA (anti-IgA antibody), due to the risk of severe immediate hypersensitivity reactions including anaphylaxis.

Regulatory history

GAMUNEX vials in strengths of 1 g, 2.5 g, 5 g, 10 g and 20 g were first listed on the ARTG on 5 May 2006. The 40 g vial was first listed on 16 September 2022. An AusPAR (Australian Public Assessment Report) was issued on 17 October 2011, approving the product for replacement therapy in Primary Immunodeficiency Diseases and Symptomatic Hypogammaglobulinaemia, and for immunomodulation in Idiopathic Thrombocytopaenic Purpura, Guillain Barré Syndrome, Chronic Inflammatory Demyelinating Polyneuropathy, and Kawasaki disease. The TGA approved GAMUNEX for an extension of indications to include Chronic Inflammatory Demyelinating Polyneuropathy and approved a new subcutaneous route of administration for the treatment of Primary Immunodeficiency.