Interferon Based Therapies
Interferon Based Therapies
Information about Interferon Based Therapies
Alpha interferon is a cytokine produced by the innate immune system in response to environmental exposures including viral infections. Alpha interferon in various formulations has been developed as therapy of several forms of cancer and viral infections, but its major use has been as therapy of chronic hepatitis C.
Liver safety of Interferon Based Therapies
Alpha interferon therapy can be associated with transient, mild-to-moderate serum aminotransferase elevations and it has been linked to induction of autoimmune conditions, including autoimmune hepatitis in susceptible persons.
Mechanism of action of Interferon Based Therapies
Alpha interferon (in"' ter feer' on) is a naturally occurring cytokine which is produced by cells of the innate immune system in reaction to viral infection or other environmental stresses. Alpha and beta interferon are considered type I interferons which share antiviral, immunomodulatory as well as antiproliferative effects. The pathways of induction and actions of alpha interferon are quite complex and the antiviral effects are due to induction of multiple intracellular genes. Overall, type I interferons produce an antiviral state inside of cells that decreases viral replication and protects against infection. There are at least 20 copies of the alpha interferon gene in the human genome and multiple formulations of standard recombinant interferon have been produced (alfa-2a, alfa-2b and alfa-con1 or “consensus” interferon). Furthermore, the interferon molecule can be pegylated which causes a prolongation of its half-life, allowing for once weekly as opposed to daily or every other day administration. Because interferon is a protein, it must be given parenterally (usually subcutaneously). Recombinant human interferons were approved for use in cancer in the 1980s, for hepatitis B in 1991 and for hepatitis C in 1992. Peginterferon became available in 2000 and has largely replaced the standard preparations.
Dosage and administration for Interferon Based Therapies
The typical dose of peginterferon alfa-2a is 180 µg once weekly for 24 or 48 weeks, and for peginterferon alfa-2b 1.5 µg/kg once weekly for 24 to 48 weeks. In chronic hepatitis C, peginterferon is usually given with ribavirin and, more recently, as triple therapy with a protease inhibitor, such as boceprevir, telaprevir, simiprevir or sofosbuvir. Ultimately, oral antiviral regimens are likely to replace peginterferon therapy in chronic hepatitis C. Standard interferon alfa is also approved for use in hairy cell leukemia, malignant melanoma, follicular lymphoma and AIDS-related Kaposi's sarcoma. Local injections of interferon are used to treat condylomata acuminata. Interferon has many side effects which often limit the dose and duration of therapy.
Side effects of Interferon Based Therapies
The following are drugs for Hepatitis C:
HCV NS5A Inhibitors
HCV NS5B (Polymerase) Inhibitors
HCV Protease Inhibitors
- Asunaprevir, Boceprevir, Glecaprevir, Grazoprevir, Paritaprevir, Simeprevir, Telaprevir, Voxilaprevir