First-line PD1/PD-L1 inhibitors for platinum-ineligible advanced urothelial carcinoma (UC).

432Background: FDA modified the label for the use of 1st-line pembrolizumab or atezolizumab therapy to PD-L1 high cisplatin-ineligible or platinum-ineligible UC patients (pts) regardless of PD-L1 expression. However, the outcomes when using PD1/PD-L1 inhibitors for platinum-ineligible pts are unclear. We conducted a retrospective study to evaluate clinical outcomes with first-line PD1/PD-L1 inhibitors for platinum-ineligible pts with advanced UC in a real-world setting. Methods: We collected data retrospectively from 6 institutions. The following criteria were deemed to render pts platinum-ineligible although physician discretion was also allowed: Cr Cl < 30 ml/min, ECOG-PS 3, Both Cr Cl 30 to < 60 AND ECOG-PS 2. Demographic and clinical variables and outcomes (overall response rate [ORR], overall survival [OS]) were collected. A Cox regression analysis was done to study the association of baseline variables with response and survival. Results: Data were available for 45 pts. Pts received atezolizumab [n ...