Researchers collaborating to develop the first vaccine capable of preventing colorectal cancer are preparing to move their investigations from animal models to human trials. Mary L. Disis, MD, is one of the researchers pursuing the vaccine as part of her 5-year American Cancer Society Clinical Research Professor Award.
“In a clinical trial, our plan is to first give the vaccine to people who have a high risk for colorectal cancer,” Disis said. “Then, if over time, we’re able to provide enough evidence about its long-term safety, in the future, the vaccine has the potential to become more widely available. Our dream is to make colorectal cancer largely a disease of the past.” She is currently preparing to solicit approval from the FDA to move the trials to humans.
According to the American Cancer Society, colorectal cancer is the second leading cause of deaths from cancer for men and women in the US combined. Approximately 4% of men and women in the US will develop colorectal cancer at some point in their lifetime, reports the ACS. That’s despite declining death rates, which are likely due to increased early detection from early screening and improved treatment options.
So far, Disis and her fellow researchers have tested their vaccine in mice models. “We found if we give the vaccine before giving mice a chemical that caused the development of polyps (and eventually colon cancer), we could prevent 80% of the polyps from becoming colon cancer,” Disis said. Additionally, said Disis, they determined that in mice whose genes had been changed to make them develop polyps and then colon cancer, the vaccine prevented 50% from developing pre-cancerous polyps.
This success was hard-won, as developing a cancer vaccine is anything but easy. As Disis explains, “In a cancer cell, the proteins look very similar to healthy proteins, so the immune system doesn’t know to attack them.” That means that the vaccine has to consider this factor.
Disis and her team hope to move their work forward, saying a colorectal cancer vaccine could change millions of people’s lives.
Sources: American Cancer Society