Programmed death ligand-1/programmed death-1 inhibition therapy and programmed death ligand-1 expression in urothelial bladder carcinoma

After two decades of unchanged paradigms, the treatment strategies for advanced urothelial bladder cancer have been revolutionized by emerging programmed death ligand-1 (PD-L1)/programmed death-1 (PD1) inhibition therapy. Increased evidence is demonstrating the efficacy of PD-L1/PD1 inhibition therapy in both second-line and first-line settings. However, the percentage of patients who benefit from anti-PD-L1/anti-PD1 therapy is still low. Many questions have been raised in the development of biomarkerdriven approaches for disease classification and patient selection. In this perspective, we discuss PD-L1/PD1 expression in urothelial bladder carcinoma, review approved anti-PD-L1/anti-PD1 agents for bladder cancer treatment and current ongoing studies investigating combination treatment strategies, and explore PD-L1 expression status for the evaluation of bladder cancer immunotherapy.