More about Immunotherapy

Keytruda is a type of immunotherapy called an immune checkpoint inhibitor. Immune checkpoints are proteins in your body that help your immune system tell the difference between your own cells and foreign invaders, such as harmful bacteria. Cancer cells sometimes find ways to use these immune checkpoint proteins as a shield to avoid being identified and attacked by the immune system. Immune checkpoint inhibitors target these immune checkpoint proteins and help the immune system recognize and attack cancer cells. PD-1 is a type of checkpoint protein found on T cells, which are immune system cells that roam throughout the body looking for signs of disease or infection. PD-L1 is another checkpoint protein found on many healthy cells in the body. When PD-1 binds to PD-L1, it stops T cells from killing a cell. Still, some cancer cells have a lot of PD-L1 on their surface, which stops T cells from killing these cancer cells. An immune checkpoint inhibitor medicine that stops PD-1 from binding to PD-L1 allows T cells to attack the cancer cells. https://www.breastcancer.org/treatment/immunotherapy/keytruda