Immune Checkpoint Inhibitors

Immune checkpoint receptors and ligands, such as programmed cell death protein 1 (PD1) and cytotoxic T lymphocyte antigen (CTLA4), are being targeted in cancer research as they are upregulated in a variety of tumor types, enabling the tumor to evade the immune system. Antagonistic antibodies targeting CTLA4 and PD1 have been developed as immunotherapies for a number of different cancers. In addition, activation of IDO and TDO in tumors inhibits T cell function and allows tumors to escape the ...