PRESS ASSOCIATION - Future cancer treatments could consist of genetically modified viruses that infect and destroy tumours, new research suggests.
Scientists have announced results from the world's first viral cancer therapy patient trial.
The study proved that a tumour-targeting virus injected into the bloodstream can find cancer wherever it has spread without harming healthy tissue.
Although the Phase I trial was designed to test safety rather than effectiveness, six of eight patients given higher doses of the therapy experienced shrinking or arrested growth of their tumours.
The most common side-effect recorded was mild to moderate flu-like symptoms that lasted less than a day.
Professor John Bell, from Ottawa Hospital Research Institute in Canada, who co-led the trial, said: "We are very excited because this is the first time in medical history that a viral therapy has been shown to consistently and selectively replicate in cancer tissue after intravenous infusion in humans.
"Intravenous delivery is crucial for cancer treatment because it allows us to target tumours throughout the body as opposed to just those that we can directly inject."
The trial involved 23 patients who all had advanced cancers that had spread to multiple organs and were not responding to standard treatments.
They received a single intravenous infusion of a virus called JX-594, derived from the cow strain used in smallpox vaccine.
One of five different dose levels was administered and 10 days later biopsy samples of tumour and healthy tissue were removed for analysis. The findings were published in the journal Nature.