Live viruses in cancer treatment.

Although antitumor activity and a low toxicity profile have been demonstrated for several oncolytic viruses, the development of viral therapy in cancer treatment has been limited by a lack of definitive phase III trials. The use of replicating viruses to potentiate the efficacy of standard cancer therapies also awaits conclusive clinical testing. Based on preliminary results with new generations of oncolytic viruses, ongoing research in this area appears encouraging. This article explores the principles of viral therapy for cancer and the past several decades of investigations with viruses such as Egypt 101, mumps, Newcastle disease, influenza, vaccinia, herpes simplex, and adenovirus serotype 5.