Canadian-made therapeutic cancer vaccine showing promise
Published Wednesday, February 6, 2013 10:09AM EST
Last Updated Wednesday, February 6, 2013 10:22AM EST
A promising Canadian-developed cancer vaccine is about to go into clinical trials in Italy to see whether it can be used safely on patients diagnosed with breast and ovarian cancer.
Immunovaccine Inc. of Halifax announced Wednesday it has signed an agreement with researchers at the Busto Arsizio Hospital in northern Italy to continue a study of its experimental vaccine, called DPX-0907.
Developed by Immunovaccine Inc., a publicly-traded biotechnology company created 10 years ago at Dalhousie University, DPX-0907 was is designed to stimulate the body's immune system to seek out and destroy cancer cells in patients with breast, ovarian and prostate cancer.
DPX-0907 is part of a new approach called therapeutic cancer vaccines. The vaccines do not prevent cancer; rather, they are to help the immune systems of patients who already have cancer to fight the disease.
Genevieve Weir, a research project manager for Immunovaccine, says the vaccine they’re working on is unique both in its content and oil-based delivery system, called DepoVax.
"It contains seven different antigens to target seven different pathways in cancer," she told CTV Atlantic in Halifax. "The vaccine itself will stay in the body for two weeks, but the immune response is long-lasting and will be maintained over several years."
By incorporating seven antigens, DPX-0907 attacks cancer cells through multiple avenues, minimizing their ability to “escape” the impact of a single antigen.
Dr. Neil Berinstein, an oncologist from Toronto’s Sunnybrook Hospital who is not involved with DPX-0907 research, explained that cancer vaccines are designed to train the body’s T cells, which are the white blood cells that play a key role in fighting cancer, to attack cancer cells.
“The idea is to augment the immune system, to make the immune system better recognize the cancer cells and to fight the cancer cells,” he told CTV’s Canada AM Wednesday.
Berinstein notes that training the immune system to target specific cells could be a superior approach to traditional cancer therapies, which kill off many more cells than necessary.
“One of the values of cancer-immune therapies is that it will directly fight the cancer and leave the rest of the body intact and not have the same sort of side effects as chemotherapy and radiation,” he said.
Berinstein says Immunovaccine’s drug also appears to have a solution for one of the fundamental problems for cancer vaccine developers: the ability of cancerous tumours to “learn” how to suppress the immune system as they grow.
“Not only do you need something to augment the immune system against the cancer, you also have to combine this with a strategy to reduce the inhibition that cancer place on the immune system,” he says.
He says it appears the Halifax team will use the work of the Italian team to skirt those problems.
“They have a very promising vaccine formulation but they’re combining it with the technology being develop din Italy to take T-cells and lymphocytes to activate them and then culture them and re-infuse them,” he said
A Phase I trial of the vaccine has already been carried out in in breast, ovarian and prostate cancer patients. The results of that study, published in the Journal of Translational Medicine in August, 2012, showed DPX-0907 was safe and well-tolerated.
The next phase of study in Italy, which will likely take a year to complete, will evaluate how well the vaccine induces an immune response to different tumour types.
“It sounds very promising. And time will tell,” says Berinstein.