In the near future, cancer patients may be treated with personalized vaccines hat spur their immune systems to attack malignant tumors.
Scientists at Washington University School of Medicine in St. Louis are evaluating personalized cancer vaccines in patients with metastatic melanoma in a clinical trial. They also are working to use the vaccines against breast, brain, lung, and head and neck cancers, and additional trials are anticipated in the next year or two.
Like flu vaccines, cancer vaccines in development are designed to alert the immune system to be on the lookout for dangerous invaders. But instead of preparing the immune system for potential pathogen attacks, the vaccines will help key immune cells recognize the unique features of cancer cells already present in the body.
In a recent study, scientists tested investigational vaccines in computer simulations, cell cultures and animal models. The results showed that the vaccines could enable the immune system to destroy or drive into remission a significant number of tumors. For example, the vaccines cured nearly 90 percent of mice with an advanced form of muscle cancer.
"This is proof that personalized cancer vaccines can be very powerful and need to be applied to human cancers now," Robert Schreiber, senior author of the study and director of the university's Center for Human Immunology and Immunotherapy Programs, said in a statement.
Creating a personalized vaccine begins with samples of DNA from a patient's tumor and normal tissue. Researchers sequence the DNA to identify mutant cancer genes that make versions of proteins found only in the tumor cells. Then they analyze those proteins to determine which are most likely to be recognized and attacked by T cells. Portions of these proteins are incorporated into a vaccine to be given to a patient.
This vaccine strategy was made possible by years of studying cancer genetics and of the immune system's interactions with cancer, researchers said.
The findings are detailed in the journal Nature.
