There are plenty of results from the past decade to illustrate that the methodology by which a therapy is delivered makes a great deal of difference to the outcome in patients. Here, for example, researchers have found a way to improve the performance of viruses engineered to preferentially target cancer cells. We've been hearing less of this approach to cancer in the past few years, given the progress and more widespread support for cancer immunotherapy as a technology platform, but there are still many researchers working on the use of viruses in targeted cancer therapy, and a number of promising studies have resulted.
The researchers found that injecting oncolytic viruses (viruses that target cancer cells) intravenously into the spleen boosts immune response faster and higher than traditional vaccine methods. Typically, physicians need to wait weeks or months to administer a booster vaccine, with the down time potentially deadly. "Normally, you have to wait until the immune response is down to administer the booster vaccine, but this means that, with severe and dangerous diseases, the response would wane. You don't want to give cancer any time to spread. What injecting the viruses into the spleen does is it allows us to bypass the regulatory mechanism that would limit its effectiveness. When we conducted these tests in animals, we saw high success rates in treatment of cancer."
The findings apply to many types of cancer, including breast cancer, leukemia, prostate cancer and osteosarcoma (bone cancer), and tumours in the brain, liver and skin. The researchers conducted the tests in mice, and in cats brought to their veterinary center. Trials on dogs should begin within the next year. Under traditional treatment options, the tumours grew and mice died. When the researchers started injecting the viruses into the spleen, the tumours disappeared. "By getting the vaccine to this unique location in the body, we were able to get an unprecedented immune response in minimal time. This is a fundamentally new way to treat cancer that bypasses many common side effects. These therapies are safer and more targeted." The findings are already leading to clinical trials for people, and the study could help researchers in other fields, including those looking to treat virulent diseases. "This research focuses on cancer, but certainly these findings would be applicable to other diseases. We just need to connect with people in those fields."