T cells protect the body from cancer by killing certain cancer cells. But cancer cells evolve proteins to protect themselves from T cells.<unk>  blocks those protective proteins. Thus, the T cells can kill the cancer cells. This is an example of immune checkpoint blockade. PD-1 is a protein on the surface of activated T cells. If another molecule, called programmed cell death 1 ligand 1 or programmed cell death 1 ligand 2 (PD-L1 or PD-L2), binds to PD-1, the T cell becomes inactive. This is one way that the body regulates the immune system, to avoid an overreaction. Many cancer cells make PD-L1, which inhibits T cells from attacking the tumor.<unk>  blocks PD-L1 from binding to PD-1, allowing the T cell to work. PD-L1 is expressed on 40–50% of melanomas and has limited expression otherwise in most visceral organs with the exception of respiratory epithelium and placental tissue.
Nivolumab
Pembrolizumab
Risankizumab
Lirentelimab
Icotinib
Bamlanivimab/etesevimab
Obiltoxaximab
Daratumumab