Mammalian subjects having a neoplasm are treated with a virus and a camptothecin compound, for example irinotecan or topotecan. The virus is selected from the group consisting of a Newcastle disease virus, a measles virus, a vesicular stomatitis virus, an influenza virus, a Sindbis virus, a picornavirus, and a myxoma virus. The treatment can also include administration of a monoclonal antibody against epidermal growth factor receptor, for example cetuximab.