Fighting Fire with Fire: Can We Kill Brain Cancer with Polio?

By Harley Everett Wilcox, MBA

Senior Scientific Advisor

ABC Laboratories
www.abclabs.com

It’s about time cancer got what it has coming, don’t you think? Imagine cancer getting just deserts just as ruthless and insidious as itself… an avaricious fighter that attacks and kills mutagenic cells while leaving its host unharmed. Now imagine that mercenary in the form of a virus—a polio virus, to be precise. Yes, the very same scourge that modern medicine virtually eliminated from the Western hemisphere during the second half of the 20^th century is back. But this time, it’s fighting for the good guys.

A few weeks ago, CBS 60 Minutes told a story of researchers who are pitting the polio virus against Glioblastoma Multiform (GBM), an aggressive brain cancer deemed incurable. Researchers reported several complete responders (possible cures) from a modified polio virus dripped into the brain tumors of patients in their 20’s and 70’s with minimal side effects. Polio booster vaccines were provided 2 weeks prior to virus injection.  Beyond the virus killing demonstration, an immune response was noted, suggesting utility in other tumor types.  Later information reported that the clinical site, Duke University Medical Center, received over 6,000 calls inquiring about the phase I glioblastoma study. This clinical report is important to oncolytic viral research—as Wollmann et al summarizes, 20 years of viral research has yielded roughly 8 clinical oncology studies, completed or ongoing albeit thus far unremarkable results¹.

Viruses are complex pieces of genetic material, are especially invasive, and often produce a disease state. Viruses are dependent upon living cells to replicate and survive, making them interesting candidates for potential cancer therapies. Standard therapy for GBM consists of surgical resection, radiation and concurrent oral chemotherapy, and offers a median survival of 14.6 months. One minor positive: Glioblastoma almost always is contained to the brain and does not metastasize to other tissues. Many modified and attenuated viruses have demonstrated pre-clinical activity with glioblastoma cells with differing biological mechanisms targeting oncological mutations to tumor cell membranes. These viruses include modified viruses such as herpes, measles, adeno, myxoma, PRV (pig herpes), and most notably polio¹.

Ironically, 90 plus percent of virgin GBM tumors are infected specifically with HCMV, Human cytomegalovirus, without peripheral infection. Cytomegalovirus, related to herpes virus, in GBM likely contributes to poor survival, increased aggressiveness, anti-apoptotic effects, and may reduce resistance to chemotherapy². Thus, viruses can readily influence tumor biology and hold promise for a cell-differentiating treatment that unleashes the power of viral machinery.

1. Wollmann G, Ozduman K, van den Pol AN. Oncolytic virus therapy of glioblastoma multiforme concepts and candidates. Cancer J. 2012; 18(1): 69–81.

2. Söderberg-Nauclér C, Johnsen, JI. Cytomegalovirus infections in brain tumors, A potential new target therapy. Oncoimmunology. 2012 Aug 1; 1(5): 739–740.