Pegylated recombinant human interferon alfa-2a is an inducer of the innate antiviral immune response (see Microbiology)

PEGASYS is an antiviral indicated for: Treatment of Chronic Hepatitis C (CHC) in patients 5 years of age and older with compensated liver disease not previously treated with interferon alpha, in patients with histological evidence of cirrhosis and compensated liver disease, and in adults with CHC/HIV coinfection and CD4 count greater than 100 cells/mm3.
• Combination therapy with COPEGUS is recommended unless patient has contraindication to or significant intolerance to COPEGUS PEGASYS monotherapy is indicated for:
•Treatment of adult patients with HBeAg positive and HBeAg negative chronic hepatitis B infection who have compensated liver disease and evidence of viral replication and liver inflammation

• PEGASYS is administered by subcutaneous injection
• In adult patients with CHC or chronic hepatitis B, PEGASYS is dosed as 180 mcg per week and the duration of treatment depends on indication, genotype, and whether it is administered with COPEGUS
• In pediatric patients with CHC, PEGASYS is dosed as 180 mcg/1.73 m2 x BSA per week, in combination with COPEGUS, and the duration of treatment depends on genotype.
• Dose reduction is recommended in patients experiencing certain laboratory abnormalities, adverse reactions or renal impairment.

The most common adverse reactions (incidence greater than 40%) are fatigue/asthenia, pyrexia, myalgia, and headache. The most common adverse reactions in pediatric subjects were similar to those seen in adults.

• Autoimmune hepatitis.
• Hepatic decompensation in patients with cirrhosis.
• Use in neonates/infants.
• Known hypersensitivity reactions such as urticaria, angioedema, bronchoconstriction and anaphylaxis to alpha interferons or any component of the product.
Additional contraindications for use with ribavirin:
• Pregnant women and men whose female partners are pregnant.
• Hemoglobinopathies (e.g., thalassemia major, sickle cell disease).
• Coadministration with didanosine

Use with Ribavirin
• Birth defects and fetal death: patients must have a negative pregnancy test prior to therapy, use 2 or more forms of contraception, and have monthly pregnancy tests.
• Hemolytic anemia.
• History of significant or unstable cardiac disease.

Patients exhibiting the following events should be closely monitored and may require dose reduction or discontinuation of therapy:
• Neuropsychiatric events.
• Autoimmune and endocrine disorders (including thyroid disorders; hyperglycemia).
• Ophthalmologic disorders.
• Cerebrovascular disorders.
• Hepatic decompensation in cirrhotic patients. Exacerbation of hepatitis during hepatitis B treatment.
• Pulmonary disorders.
• Infections (bacterial, viral, fungal).
• Bone marrow suppression.
• Colitis and pancreatitis.
• Hypersensitivity and serious skin reactions including Stevens-Johnson syndrome. See package insert for complete information.