Neoantigen vaccines use the DNA from a cancer patient’s own tumor to, hopefully, eradicate the cancer.
For some 50 years, cancer biologists have tried to incite the immune system to attack cancer by targeting molecules that commonly stud the surfaces of malignant cells. These “antigens” act as homing beacons that immune cells find and lock onto (much as antigens on viruses attract the immune system, the basis for preventive vaccines such as that for measles).
Trouble is, normal cells sometimes sport the same antigens as tumors, and the immune system is programmed not to attack antigens found on healthy cells. As a result, revving up the immune system to target common tumor antigens hasn’t worked, leading to a number of failed experimental cancer vaccines.
That led biologists to a different approach: siccing the immune system on antigens found only on cancer cells — and only on the cancer cells of a single patient. “It’s highly unlikely that any two patients have the same neoantigens,” said Dr. Catherine Wu of Boston’s Dana-Farber Cancer Institute. “That’s why we have an opportunity to make cancer vaccines truly personalized, loaded with patient-specific neoantigens.”