Canadian-made virus shows promise as cancer treatment

An Ottawa-based research team has developed a virus that is showing promise as a new way of attacking and shrinking cancer tumours while leaving healthy tissue alone. It''s early days in the still-experimental field of therapeutic cancer viruses, called oncolytic viruses. But this new study from researchers from the Ottawa Hospital Research Institute (OHRI) and the University of Ottawa advances the field a little further by showing that the virus is safe in most patients. For the study, researchers recruited 23 advanced cancer patients whose cancer had spread to multiple organs. All had failed to respond to the usual treatments and all were in the final stages of the disease. The patients agreed to receive a single infusion of an experimental virus into their blood, called JX-594. JX-594 is a form of vaccinia virus that''s been used as a live vaccine against smallpox. The JX-594 virus has been genetically engineered to enhance its natural anti-cancer properties. The doctors tried out five doses of the virus, and then took biopsies of the tumours eight to 10 days later. The researchers found that seven of the eight patients in the highest dose groups had evidence that the virus was in place and replicating in their tumours -- and not in normal tissues. Dr. John Bell, one of the study''s co-authors and a researcher at OHRI says it''s exciting that the virus led to results after just one dose. "Of course, we will need to do more trials to know if this virus can truly make a difference for patients," he said in a statement.