INTRON® A (Interferon alfa-2b, recombinant) Injection is a recombinant version of naturally occurring alfa interferon that has been shown to be an effective antiviral and anticancer treatment. In chronic viral hepatitis patients, interferons act by boosting the antiviral functions of the immune system. INTRON® A is obtained from the bacterial fermentation of a strain of genetically engineered Esherichia coli in a nutrient medium containing the antibiotic tetracycline, which is not detectable in the final product.

INTRON® A is approved by the Food and Drug Administration as monotherapy for the treatment of chronic hepatitis B (HBV) and C (HCV) infections. A course of therapy for hepatitis B is 6 months. A course of therapy for hepatitis C is up to 24 months.

See "INTRON® A Clinical Studies/Outcomes"
See "Candidates for Treatment."



Interferons

Interferons are a family of naturally occurring small proteins and glycoproteins. Produced and secreted by a number of endogenous cells in response to viral infection, interferons exert their cellular activities by binding to specific membrane receptors on the cell surface. Once interferons bind to the cell membrane, they initiate a complex sequence of intracellular events, including the induction of certain enzymes, suppression of cell proliferation, immunomodulating activities�such as enhancement of phagocytic activity of macrophages and augmentation of the specific cytotoxicity of lymphocytes for target cells�and inhibition of viral replication in infected cells. In manufactured therapeutic form, interferon stimulates the immune system to fight viral infection and can inhibit viral division in liver cells.