BETAFERON

What it is

BETAFERON is interferon beta-1b powder for injection vial with diluent syringe, containing 8 million IU (0.25 mg) of interferon beta-1b per mL of reconstituted solution. Interferon beta-1b is a purified, sterile lyophilised protein with 165 amino acids and an approximate molecular weight of 18,500 daltons, produced by recombinant DNA techniques from a strain of Escherichia coli bearing a genetically engineered plasmid containing a modified human interferon beta gene.

Approved indications

— Treatment of patients with a single clinical event suggestive of multiple sclerosis and at least two clinically silent magnetic resonance imaging (MRI) lesions characteristic of multiple sclerosis, if alternative diagnoses have been excluded. — Treatment of ambulatory patients with relapsing-remitting multiple sclerosis (MS) characterised by at least two attacks of neurologic dysfunction over a two year period followed by complete or incomplete recovery. — Reduction of frequency and severity of clinical relapses, and slowing of progression of disease in patients with secondary progressive multiple sclerosis.

Dosing overview

Treatment with interferon beta-1b should be initiated under the supervision of a physician experienced in the treatment of multiple sclerosis.

Key safety warnings

Serious hypersensitivity reactions (rare but severe acute reactions such as bronchospasm, anaphylaxis, and urticaria) may occur. If reactions are severe, interferon beta-1b should be discontinued and appropriate medical intervention instituted. Patients to be treated with interferon beta-1b should be informed that depression and suicidal ideation may be a side effect of the treatment and should report these symptoms immediately to the prescribing physician. In rare cases these symptoms may result in a suicide attempt. Patients exhibiting depression and suicidal ideation should be monitored closely and cessation of therapy should be considered. In rare cases, pancreatitis was observed with BETAFERON use, often associated with hypertriglyceridaemia. Injection site infection and injection site necrosis have been reported in patients using BETAFERON. Injection site necrosis can be extensive and may involve muscle fascia as well as fat and therefore can result in scar formation. Occasionally debridement and, less often, skin grafting are required and healing may take up to 6 months. Cases of pulmonary arterial hypertension (PAH) have been reported with interferon beta products, including BETAFERON. PAH has occurred in patients treated with interferon beta products in the absence of other contributory factors. Many of the reported cases require hospitalisation, including one case with interferon beta in which the patient underwent a lung transplant. PAH has developed at various time points after initiating therapy with interferon beta products and may occur several years after starting treatment. Asymptomatic elevations of serum transaminases, in most cases mild and transient, occurred very commonly in patients treated with BETAFERON during clinical trials. Rare cases of severe hepatic injury, including cases of hepatic failure have been reported. Cases of thrombotic microangiopathy, manifested as thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome, as well as cases of haemolytic anaemia not associated with thrombotic microangiopathy, have been reported with interferon beta therapy, including life-threatening and fatal cases.

Contraindications

BETAFERON is contraindicated in patients with a history of hypersensitivity to natural or recombinant interferon beta or to any of the excipients.

PBS listing

An injection set including 1 vial powder for injection 8,000,000 I.U. (250 micrograms) and solvent is listed on the PBS with streamlined restriction at an ex-manufacturer price of A$668.82.

Regulatory history

BETAFERON (interferon beta-1b rbe 0.25 mg / 8 million IU powder for injection vial with diluent syringe) was first registered on the Australian Register of Therapeutic Goods on 9 August 2002.