Intravenous durvalumab (Imfinzi™; AstraZeneca) is a fully human monoclonal 
antibody that blocks programmed cell death ligand-1 binding to its receptors 
(PD-1 and CD80), resulting in enhanced T-cell responses against cancer cells. 
The US FDA has granted durvalumab accelerated approval for the treatment of 
patients with locally advanced or metastatic urothelial carcinoma who have 
disease progression during or following platinum-containing chemotherapy, or 
within 12 months of neoadjuvant or adjuvant platinum-containing chemotherapy. 
Durvalumab ± tremelimumab is under phase III clinical trials in urothelial 
carcinoma, non-small cell lung cancer, small cell lung cancer and head and neck 
squamous cell carcinoma. The drug is also being evaluated in phase I or II 
clinical trials in a wide range of solid tumours and haematological 
malignancies. This article summarizes the milestones in the development of 
durvalumab leading to this first approval for urothelial carcinoma.