Alfernon Reference Site

Interferon alfa-n3 has exhibited antiproliferative effects in preclinical studies employing both cell culture systems and human tumor xenografts in animals, and has demonstrated significant immunomodulatory activity in vitro. Interferon alfa-2b also inhibits viral replication in vitro and in vivo.

Interferons exert their cellular activities by binding to specific membrane receptors on the cell surface. The results of several studies suggest that, once bound to the cell membrane, interferon initiates a complex sequence of intracellular events that include the induction of certain enzymes. It is thought that this process, at least in part, is responsible for the various cellular responses to interferon, including inhibition of virus replication in virus-infected cells, suppression of cell proliferation and such immunomodulation activities as enhancement of the phagocytic activity of macrophages and augmentation of the specific cytotoxicity of lymphocytes for target cells. All of these activities possibly contribute to interferon's therapeutic effects.

For the treatment of chronic hepatitis C in patients 18 years or older with compensated liver disease who have a history of blood or blood product exposure and/or are HCV antibody positive. Studies in these patients demonstrated that INTRON A can produce normalization of ALT, clearance of serum HCV RNA and improvement in liver histology.

For the treatment of chronic active hepatitis B in patients 18 years of age or older with compensated liver disease and who have evidence of viral replication. Patients must be serum HBsAg positive for at least 6 months and have HBV replication, as demonstrated by positive serum HBeAg, with elevated serum ALT.

Studies in these patients demonstrated that INTRON A therapy can produce virologic remission of this disease (loss of serum HBeAg and HBV-DNA) and normalization of serum aminotransferases. INTRON A therapy resulted in the loss of serum HBsAg in some responding patients.

INTRON A is not indicated for the treatment of patients who are chronic carriers of hepatitis B surface antigen (HBsAg) but lack evidence of viral replication (serum HBeAg negative).

For the treatment of patients with chronic myelogenous leukemia (CML). Studies have demonstrated a greater likelihood of response to INTRON A therapy in patients who are in the chronic phase of the disease.

Thrombocytosis is frequently associated with CML. During the clinical experience accumulated to date, approximately one-quarter (26%) of the patients diagnosed with CML had concomitant thrombocytosis, with a baseline platelet count of greater than 500×10⁹/L. Platelet control was achieved in all patients within 2 months of treatment. At no time were monthly platelet counts <80×10⁹/L.