Immunotherapy in urothelial cancer: recent data and perspectives

Immune-checkpoint inhibitors blocking the programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) and cytotoxic T-lymphocyteassociated protein 4 (CTLA-4) have shown a prominent anti-tumor activity with long-term responses and an acceptable toxicity profile in clinical trials. Pembrolizumab, atezolizumab, nivolumab, avelumab, and durvalumab are anti-PD-1/PD-L1 agents that redefine the standard of care for advanced urothelial carcinoma. CTLA-4 inhibitors are also under investigation in this setting. Phase III trial KEYNOTE-045 has demonstrated significant survival benefit in patients treated with pembrolizumab comparing with the standard second-line chemotherapy. Atezolizumab, nivolumab, avelumab, and durvalumab were also recommended for platinum-pretreated urothelial carcinoma patients based on phase II data. Following investigations of biomarkers such as PD-L1 expression are needed to determine high-responders to immunotherapy. This review article describes the advances in immunotherapy with immune-checkpoint inhibitors.