A Hamilton grown cancer vaccine is part of a ground breaking trial that was just announced in Ottawa Friday morning. Several patients have undergone treatment that uses viruses to help the body attack its own cancer cells. Cancer cells don’t always look that different from normal cells, so sometimes the immune system fails to identify them and that is when they can grow out of control. This new therapy primes the immune system to attack the cancer aggressively, without damaging healthy tissue. It’s a promising discovery, especially for patients who have no other options left.
Tumours of potential patients are biopsied at St. Joseph’s hospital for the Mage-A3 protein, which is typically found in melanomas, lung cancers and abdominal cancers. The Mage-A3 protein triggers “attack mode” in the two viruses being used in this trial. Adenovirus was developed at McMaster University; it trains the immune system to go after cancer cells that carry Mage-A3. The second virus in the trial is called Maraba virus which was engineered in Ottawa. It both turns the immune system against cancer cells and attacks the cells itself.
So far, 9 patients have been treated at trial sites in Hamilton, Ottawa and Toronto and none have experienced significant side effects. Each patient is only receiving one of the two viruses to start, but soon doctors will start administering both which will be a world first. About 30% of patients whose tumours have been tested at St.Joe’s carry the Mage-A3 marker. The trial is expected to treat 79 patients in total.