Several programmed death ligand-1 (PD1/L1) immune checkpoint inhibitors (ICIs) are approved in urothelial carcinoma (UC).
To address the need for predictors of the efficacy of ICIs in metastatic urothelial carcinoma (mUC), randomized controlled trials of PD1/L1 inhibitors alone or in combination with chemotherapy in this patient population were systematically reviewed, and differences in ICI-associated survival outcomes according to available baseline variables were quantitatively assessed.