Oncolytic viruses.

Viruses capable of inducing lysis of malignant cells through their replication process are known as "oncolytic" viruses. Clinical trials in oncology have been performed with oncolytic viruses for nearly fifty years. Both systemic and intratumoral routes of administration have been explored. Toxicity has generally been limited to injection site pain, transient fever and tumor necrosis. Responses with early crude materials were usually short in duration; however, recent trials with gene attenuated viruses suggest more prolonged duration to responses observed.