Therapeutics: Dipeptidyl peptidase-4 (DPP-4; CD26); programmed cell death 1 (PD-1; PDCD1; CD279); CTLA4 (CD152)

Mouse studies suggest combining DPP-4 inhibitors with immune checkpoint inhibitors could help treat cancer. In a mouse model of melanoma, homozygous knockout of DPP-4 decreased tumor growth compared with heterozygous DPP-4 knockout. In a mouse model of colon cancer, the DPP-4 inhibitor Januvia sitagliptin increased numbers of tumor-infiltrating CD3-positive T cells and NK cells and decreased tumor growth compared with vehicle. In the melanoma model, Januvia plus mAbs against PD-1 and CTLA-4 decreased tumor growth compared with the two mAbs or any agent alone. Next steps include testing DPP-4 inhibitors in clinical trials on hepatocellular carcinoma (HCC)...