Our expanding knowledge of immunotherapy for solid tumors has led to an 
explosion of clinical trials aimed at urothelial carcinoma. The primary strategy 
is centered on unleashing the immune system by releasing the inhibitory signals 
propagated by programmed cell death-1 (PD-1) and its ligand programmed cell 
death ligand-1 (PD-L1). Many antibody constructs have been developed to block 
these interactions and are used in clinical trials. The Food and Drug 
Administration has already approved a number of checkpoint inhibitors such as 
anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) monoclonal antibodies 
including ipilimumab; anti-PD-1 monoclonal antibodies including nivolumab and 
pembrolizumab; anti-PD-L1 antibodies including atezolizumab, avelumab, and 
durvalumab. One of the latest inhibitors is durvalumab, which is a high-affinity 
human immunoglobulin G1 kappa monoclonal antibody and blocks the interaction of 
PD-L1 with PD-1 and CD80. Currently, there are a number of ongoing trials in 
advanced urothelial carcinoma both using durvalumab monotherapy and in 
combination with other targeted therapies. In addition, durvalumab is being 
investigated in the non-muscle-invasive urothelial carcinoma, which is centered 
around intravenous formulations. These exciting developments have added a 
significant number of therapies in a previously limited treatment landscape.