New trial shows cancer vaccine cuts risk of melanoma returning

At Europe's top medical conference for cancer, the results of a clinical trial that could bring scientists one step closer to a cancer vaccine. It's built on over 100 years of discovery and work on cancer biology, cancer immunology and innovative technological advances. The phase three trial looked at over 1,000 patients with high-risk melanoma receiving immunotherapy after surgery. Those who also received the new vaccine personalized for each patient based on their tumor were 42% less likely to have the cancer return after two years. It's a proof of concept that we can look at cancer and utilize the immune system in a different way. It's a completely new mechanism of action that we've been trying to achieve for many, many decades. Over the summer, manufacturers Moderna and Merck had teased the top-line results. Now with details, there's renewed excitement among those testing this technology to fight other cancers. This is the first time where we see very advanced data on not only the efficacy of the vaccine, but also its safety. The shot uses mRNA technology, developed rapidly during the COVID pandemic. Many of these mRNA vaccines were initially developed for cancer, actually. and then were repurposed for COVID and now are being reapplied to cancer. But there is a caveat. The impact of the mRNA vaccine on long-term survival is still being studied. We need to collect more data to see what the impact on overall survival is. Personalised therapies like this also are likely to carry a higher price tag. And doctors say Canadian authorities should start thinking about that now, as Moderna and Merck prepare to submit their clinical dossiers to regulators like Health Canada. Jennifer Yoon, CBC News, Toronto.