Design of virotherapy for effective tumor treatment.

The use of viruses as therapeutic agents against cancer is an old concept that has had a significant revival in the past two decades, in parallel with advances in methods to modify viral genomes genetically. From the initial stage of proof of concept, the field of virotherapy quickly progressed to the clinical setting, where serious limitations, yet promising opportunities, were identified. After demonstrating good safety profiles in humans, the objective in virotherapy has become to improve the efficacy of oncolytic viruses. Virotherapy approaches include incorporating therapeutic genes, evaluating alternative viruses with stronger oncolytic potential, employing new methods to improve biodistribution, and establishing greater insight into the influence of the immune system on both the success and failure of therapies. This review summarizes the most significant advances in recent years in the design of virotherapy for effective tumor treatment.