(UroToday.com) There are several PD-1 immune-checkpoint inhibitors including nivolumab that are approved in urothelial cancer. Recently, in the front-line setting, improved activity of combined PD-L1 and CTLA4 immune-checkpoint inhibition has been reported and a phase III trial with nivolumab plus ipilimumab is ongoing. At the American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU),  Dr. Marc-Oliver Grimm and colleagues presented results of their study assessing a response-based tailored approach starting treatment with nivolumab monotherapy using nivolumab plus ipilimumab as immunotherapeutic “boost”.