Research progress on PD-1 and PD-L1 inhibitors in the treatment of metastatic urothelial carcinoma

Urothelial carcinoma (UC) is a very common malignant tumor. In the past few decades, platinum-based chemotherapy has been regarded as the standard recommended regimen for patients with metastatic urothe-lial carcinoma (mUC) who can receive either cisplatin or carboplatin. The emergence of immune checkpoint inhibitors (ICIs) brought some hope for possible treatments for mUC patients who were unfit for platinum therapy. ICIs drugs have emerged as new potential weapons to overcome UC in our lifetime. ICIs block the binding of programmed death-1 (PD-1) to programmed death-ligand 1 (PD-L1), leading to enhancement of the immune function of antitumor T cells. In the treatment of UC, ICIs show an apparent ascendancy and effectively enhance survival rates. With good tolerability and remarkable effects, ICIs have given thousands of patients hope. This article mainly shows the application of PD-1 and PD-L1 inhibitors in mUC.