PEGASYS

What it is

Pegasys is peginterferon alfa-2a. It is a solution for injection. Pegasys is available as 135 micrograms or 180 micrograms in pre-filled syringes containing 0.5 mL solution.

Approved indications

— Treatment of chronic hepatitis C in combination with ribavirin in patients who have received no prior interferon therapy and in patients who have failed previous treatment with interferon alfa alone or in combination therapy with ribavirin. — Treatment of chronic hepatitis C in combination with ribavirin in patients with clinically stable human immunodeficiency virus co-infection who have previously not received interferon therapy. — Treatment of chronic hepatitis C as monotherapy in treatment-naïve patients. — Treatment of chronic hepatitis B in adult patients with evidence of viral replication and liver inflammation and compensated liver disease. Patients must be 18 years of age or older and have compensated liver disease.

Dosing overview

The recommended dose of Pegasys, alone or in combination with oral ribavirin, is 180 micrograms once a week by subcutaneous administration in the abdomen or thigh. For chronic hepatitis C combination therapy, the duration of combination therapy and the daily dose of ribavirin should be individualised based on the patient's viral genotype, with 48 weeks of treatment for genotypes 1 and 4, and 24 weeks for genotypes 2 and 3. The recommended duration of Pegasys monotherapy is 48 weeks. For chronic hepatitis B, the recommended dose is 180 micrograms once a week by subcutaneous administration, with a recommended duration of therapy of 48 weeks. When dose modification is required for moderate to severe adverse reactions, initial dose reduction to 135 micrograms is generally adequate; however, dose reduction to 90 micrograms or 45 micrograms may be necessary in some cases.

Key safety warnings

Severe psychiatric adverse reactions may manifest in patients receiving Pegasys, including depression, suicidal ideation, suicide, relapse of drug dependence and drug overdose, which may occur in patients with or without previous psychiatric illness. Pegasys should be used with caution in patients who report a history of depression, and physicians should inform patients of the possible development of depression prior to initiation of therapy. Pulmonary symptoms, including dyspnoea, pulmonary infiltrates, pneumonia, and pneumonitis, including fatality, have been reported during therapy with Pegasys, and if there is evidence of persistent or unexplained pulmonary infiltrates or pulmonary function impairment, treatment should be discontinued. Cases of pulmonary arterial hypertension have been reported with Pegasys and may develop at various time points after initiating therapy or several years after starting treatment; patients who develop unexplained symptoms should be assessed for this condition and treatment should be discontinued if a diagnosis is confirmed. Retinopathy including retinal haemorrhages, cotton wool spots, papilloedema, optic neuropathy and retinal artery or vein obstruction, which may result in loss of vision, have been reported; all patients should have a baseline eye examination and any patient complaining of decreased or loss of vision must have a prompt and complete eye examination, with treatment discontinued if new or worsening ophthalmologic disorders develop. Cardiovascular events such as hypertension, supraventricular arrhythmias, congestive heart failure, chest pain and myocardial infarction have been associated with interferon therapy; it is recommended that patients with pre-existing cardiac abnormalities have an electrocardiogram prior to and during treatment, and therapy should be suspended or discontinued if there is any deterioration of cardiovascular status. Serious and severe infections (bacterial, viral, fungal) have been reported during treatment with Pegasys, and appropriate anti-infective therapy should be started immediately with discontinuation of therapy considered.

Contraindications

Pegasys is contraindicated in patients with known hypersensitivity to alfa interferons, to E. coli-derived products, to polyethylene glycol or to any component of the product; autoimmune hepatitis; decompensated cirrhosis; and HIV-HCV co-infection with cirrhosis and a Child-Pugh score ≥ 6, except if only due to indirect hyperbilirubinemia caused by medicines such as atazanavir and indinavir. Pegasys is contraindicated in neonates and infants up to the age of 3 years because of the excipient benzyl alcohol. When used in combination with ribavirin, Pegasys is contraindicated in patients with a history of severe pre-existing cardiac disease, including unstable or uncontrolled cardiac disease in the previous 6 months; patients with haemoglobinopathies such as thalassaemia or sickle-cell anaemia; women who are pregnant or breast-feeding; and men whose female partners are pregnant or are not using adequate contraception.

PBS listing

Pegasys 135 micrograms in 0.5 mL single use pre-filled syringe is listed on the PBS with streamlined and unrestricted restrictions across 3 items, with an ex-manufacturer price of A$828.64 to A$1179.57 depending on the specific item. Pegasys 180 micrograms in 0.5 mL single use pre-filled syringe is listed on the PBS with streamlined and unrestricted restrictions across 3 items, with an ex-manufacturer price of A$959.63 to A$1232.46 depending on the specific item.

Regulatory history

Pegasys was registered on the ARTG on 28 May 2003, with both the 135 microgram and 180 microgram formulations listed simultaneously. In November 2017, the PBAC recommended a change in PBS listing from Authority Required (Streamlined) and Authority Required to Unrestricted, on the basis of a proposed price reduction and risk sharing arrangements.