(UroToday.com) Immune checkpoint inhibitors (ICIs) such as atezolizumab (PD-L1), are considered standard therapy for patients with metastatic urothelial carcinoma (mUC) that has progressed after first-line platinum-based chemotherapy. However, only close to 20% of patients will derive sustained benefit from ICI treatment. Therefore, it is critical to find factors associated with the enhanced efficacy of ICIs in this setting. Several factors defined by Bellmunt et al.1 have been shown to affect expected overall survival (OS) in patients treated with second-line vinflunine.