Sangeeta Goswami, MD, PhD, University of Texas MD Anderson Cancer Center, Houston, TX, discusses the use of combinatorial biomarkers to predict response to immune checkpoint inhibitor (ICI) therapy in metastatic urothelial cancer (mUC) at ASCO GU 2021. Retrospective multi-platform immuno-genomic analyses of pre-treatment tumor tissues was performed in a discovery cohort of 31 patients. The analysis identified genomic mutation of ARID1A and expression of the immune cytokine CXCL13 in pre-treatment tumor tissue as a predictor of clinical response to ICI therapy. These findings were then extended to the CheckMate 275 trial (NCT02387996) and the IMvigor210 trial (NCT02951767, NCT02108652) where it was found that CXCL13 expression plus ARID1A mutation were associated with improved overall survival in patients receiving ICI therapy. This interview took place during the 2021 Genitourinary Cancers Symposium.