PD-L1 expression on immune cells by SP142 co-localises with dendritic cells and is associated with improved overall survival (OS) with atezolizumab in patients with untreated metastatic urothelial cancer (mUC)

PD-L1 assays use various methods (e.g., scoring tumour and/or immune cells) to predict PD-L1/PD-1 blockade outcomes. Data suggest that the clinically relevant PD-L1–expressing immune cells (IC) are dendritic cells (DCs) (Oh 2020). Here, we probed the clinical and immunologic basis underlying the trend toward favourable OS with atezolizumab alone (atezo; anti–PD-L1; Arm B) vs placebo + platinum/gemcitabine chemotherapy (chemo; Arm C) in patients (pts) with high PD-L1 by SP142 in the Ph 3 IMvigor130 trial (ITT: HR, 0.68, 95% CI: 0.43, 1.08; cisplatin ineligible: HR, 0.53, 95% CI: 0.30, 0.94) (Galsky ASCO-GU 2021; 31 May 2019 cutoff).