Pegylated interferon alfa-2a is an antiviral drug discovered at the pharmaceutical company F.Hoffmann-La Roche; it has a dual mode of action - both antiviral and on the immune system. This drug is approved around the world for the treatment of chronic hepatitis C and has recently been approved for the treatment of chronic hepatitis B. , Interferon , PEGylation , , , , de:Peginterferon