(UroToday.com) Survival rates are low for patients with metastatic urothelial carcinoma after disease progression with platinum-based chemotherapy, but the use of immune checkpoint inhibitors as second-line therapy has shown improved outcomes. The PD-1 inhibitor pembrolizumab is the only second-line therapy recommended for use after platinum-based chemotherapy, based on the phase 3 KEYNOTE-045 trial that showed significantly improved OS with use of pembrolizumab with lower rates of adverse events than chemotherapy,1 with these benefits being maintained at 2 years and 3 years of follow-up.2 At the American Society of Clinical Oncology (ASCO) 2021 Annual Meeting, Dr. Joaquim Bellmunt and colleagues presented updated results from the KEYNOTE-045 trial after >5 years of follow-up since the last patient was randomized.