Immunotherapy has revolutionized cancer care in the modern era of oncology. 
Research in immunotherapy has led to important advances in the treatment of 
melanoma, non-small cell lung cancer and other malignancies using checkpoint 
inhibition. Multiple systemic immunotherapies have been approved or are 
currently being investigated for the management of urothelial malignancies (1). 
Five antibodies targeting the programmed cell death protein 1--programmed cell 
death 1 ligand 1 (PD-1--PD-L1) pathway have been approved by the U.S. Food and 
Drug Administration (FDA) for the management of various malignancies: 
pembrolizumab, nivolumab, atezolizumab, durvalumab and avelumab. Recent 
publications illustrate that in specific stages, immunotherapy is more effective 
than chemotherapy with a better toxicity profile (1). Currently, the only 
FDA-approved indication for the anti-PD-L1 monoclonal antibody durvalumab 
(MEDI-4736) is locally advanced or metastatic urothelial carcinoma that has 
progressed during or following platinum-based chemotherapy within 12 months of 
treatment. This article summarizes the milestones in the development of 
durvalumab leading to its approval for urothelial carcinoma.