An international research team that includes Canadian scientists has completed a preliminary study demonstrating that a genetically engineered virus can be used to attack cancer tumours – without harming surrounding tissues.
Earlier studies have shown that some viruses have the ability to infect cancer cells along with other tissues. Based on these findings, Jennerex Biotherapeutics Inc. – a company founded by researchers John Bell in Ottawa and David Kirn in San Francisco – set out to modify one virus so it targets only cancer cells.
“The virus travels through the blood and selectively infects tumours and destroys them and it won’t infect normal tissues,” explained Dr. Bell, a scientist at the Ottawa Hospital Research Institute. “Patients should have very few side effects.”
In the first human trial, copies of the modified virus – called JX-594 – were injected into 23 patients suffering from untreatable metastatic cancer that had spread. The results, published this week in the journal Nature, indicate that some tumours showed evidence of shrinkage.
The patients participating in the trial received just one treatment. Dr. Bell said they may derive more benefit with additional treatments. It may also be possible to make the viruses more potent tumour-killers by equipping them with certain genes.
“We are still in the early stages of testing these viruses in patients,” noted Dr. Bell. “But I believe that, some day, viruses and other biological therapies could truly transform our approach to treating cancer.”