Metastatic urothelial carcinoma (UC) remains an aggressive disease associated 
with limited treatment options and a reduced survival. In spite of this, the 
first-line treatment based on platinum-based combinations has remained virtually 
unchanged for the last 20-30 years. Similarly, before the advent of the immune 
checkpoint inhibitors, there were no FDA-approved drugs for second-line therapy. 
In the last few years, impressive signs of anti-tumor activity have been 
reported with several immunotherapy agents targeting the programmed cell death-1 
(PD-1) pathway. Avelumab, a PD-1 ligand (PD-L1) inhibitor, is currently being 
investigated for the treatment of UC. Areas covered: This article will review 
the pharmacological characteristics of avelumab, the efficacy studies which led 
to its approval, its safety profile, as well as its place within the management 
of urothelial carcinoma with immunotherapy. For that matter, we undertook a 
literature review of all the studies assessing the pharmacology of avelumab and 
its efficacy within clinical trials. Expert commentary: Avelumab has shown 
promising antitumor activity and a manageable safety profile in patients with 
UC. Its dual mechanism of action, blocking the interaction between PD-L1 and 
PD-1 and promoting antibody-dependent cell-mediated cytotoxicity could 
potentially be of great interest since it could produce synergistic clinical 
efficacy.