Funded by the Cancer Vaccine Coalition (CVC)
The INTERCEPT‑HER2 study is testing a new vaccine for people with HER2‑positive breast cancer who have finished all standard treatments but still show tiny signs of cancer in their blood. These signs are called minimal residual disease (MRD). MRD cannot be seen on scans, but it can warn us that the cancer may return. Finding MRD gives doctors a chance to act earlier, when the cancer is very small and the immune system is still strong.The vaccine uses cancer proteins to train the immune system to find and attack cancer cells. Earlier studies showed that the vaccine is safe and can activate the immune system, so it may help stop the cancer from growing again. In this study, 45 patients who test positive for MRD in the blood will receive three monthly vaccine doses and then two booster shots. They will also have regular blood tests for up to three years to see if the cancer signals in their blood go down or disappear.The main goals are to learn whether the vaccine can delay or prevent the cancer from coming back and whether it can clear MRD from the blood. The study will also show how often people with breast cancer still have MRD after treatment. Blood samples will help researchers understand how the immune system responds to the vaccine. What we learn may guide a larger future study and could lead to new ways to stop breast cancer earlier, before it becomes harder to treat.
