Oncolytic viruses: perspectives on clinical development

•Oncolytic virus (OV) clinical development is more complex than other therapeutics.•‘Window of opportunity’ studies should be considered in the development process.•A well thought out clinical development plan is an essential element of the process.•OV infectious potential should be factored into clinical trial design and conduct.•OV have the potential to help overcome heretofore incurable disease.

Developing a live anti-cancer agent derived in most cases from human pathogens presents a unique set of challenges to clinical development versus those anticipated with standard chemotherapeutics and small molecules. The selection of therapeutic targets for oncolytic virus (OV) clinical development, as is true with the development of any agent for cancer therapy, requires careful consideration beyond preclinical and early clinical data, especially when multiple indications may initially appear equally promising. Further, the added complexity of the potential for infectious complications following OV therapy must be anticipated in order to efficiently and safely conduct clinical studies. As more OV enter the clinic, these issues will become increasingly important to successful OV drug development.