Very interesting 60 Minutes last night about a Phase I study at Duke where a modified version of the poliovirus is being used to treat brain cancer -
http://www.cbsnews.com/news/polio-cancer-treatment-duke-university-60-minutes-scott-pelley/. The modified poliovirus binds to the CD155 receptors (which is over-produced in brain tumors) and destroys the cancerous cells, while leaving normal tissue alone. I found a better explanation of the mechanics at -
http://corporate.dukemedicine.org/news_and_publications/news_office/news/7273. It sounded like Duke may be able to apply for Fast Track Designation in about 12 months and that this technology may be able to be used to treat most all cancers.