Picornavirus promising against metastatic cancer

November 15, 2007

NEW YORK (Reuters Health) - The newly discovered native picornavirus Seneca Valley Virus-001 shows powerful and selective cytolytic action in tumor cell lines, researchers report in the November 7th issue of the Journal of the National Cancer Institute.

"The implications of this work," senior investigator Dr. Paul L. Hallenbeck, told Reuters Health, "is that we may be able to treat cancer metastases with these kind of viruses as they are not inhibited by any component of human blood, appear safe to normal tissue, and are very potent in killing certain types of cancer cells."

Dr. Hallenbeck of Neotropix Inc, Malvern, Pennsylvania and colleagues studied the action of the virus in cell lines from small-cell lung cancers and pediatric tumors. Cytolysis was at least 10,000 times greater in these cells than in normal human cells.

No dose-limiting toxicity was seen in normal mice. In 10 mice with small-cell lung tumors, a single intravenous dose of virus resulted in all showing complete and durable responses. This was also true of 8 of 10 mice with retinoblastoma tumors.

"Other viruses have been tried here," Dr. Hallenbeck observed, "but are inactivated by one or more components of human blood -- thus they never reach the tumor or are too toxic toward normal cells, so doses can never be achieved that allow the virus to really infect and kill tumors."

"This virus," continued Dr. Hallenbeck, "has been shown to have exquisite tropism -- the ability to only infect certain cell types -- for tumor cells that have neuroendocrine properties." Many cancers, he noted, are of this category.