Skin autoimmunity might be associated with increased efficacy of atezolizumab in metastatic urothelial carcinoma: a case report.

Atezolizumab is a monoclonal antibody immune checkpoint inhibitor that binds to programmed death ligand 1 to selectively prevent its interaction with programmed cell death-1 (PD-1) and B7.1 (CD80) receptors. We present a case of a 61-year-old man with metastatic urothelial carcinoma of the right ureter and urinary bladder. After gemcitabine/cisplatin as the first-line chemotherapy and surgery, the patient received atezolizumab 1200 mg i.v. q3w. Following the first atezolizumab administration, he noted vitiligo periorally, on his hands, legs, and the scalp. The patient's overall survival (OS) of >26 months and continuing response to atezolizumab treatment is considerably better than median OS in the SAUL study of 8.7 months (IMvigor211-like patients' OS 10.0 months). This case indicates that increased efficacy of atezolizumab can be associated with cutaneous immune related adverse events, reflecting the known Th17 polarization of these diseases and showing that individuals with cutaneous adverse events could benefit from PD-1 checkpoint blockade in the therapy of metastatic urothelial carcinoma.