Repeat Treatment of Patients With Advanced Urothelial Carcinoma With Immune Checkpoint Inhibitors Following Prior Progression on a Checkpoint Inhibitor Regimen: A Case Series.

ABSTRACT

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have become one of the mainstays of systemic therapy for advanced urothelial carcinoma (aUC). Increasingly ICIs are also being utilized earlier in the course of UC treatment. Limited data are available regarding ICI treatment efficacy in aUC patients who have progressed on prior ICI regimens. This case series aims to address this knowledge gap. PATIENTS AND METHODS: We identified all aUC patients treated with ICI or combination following prior progression on another ICI regimen at two academic institutions. Patient demographic, clinicopathologic and treatment data were retrospectively collected from chart review at each site. Best response to ICI treatment was defined by investigator at each site. RESULTS: Among 7 patients with aUC who received ICI treatment following prior progression on a different ICI regimen, radiographic response to the second ICI regimen was observed in only 1 patient (14%) treated with combination of pembrolizumab/enfortumab vedotin. CONCLUSION: Efficacy of ICI treatment in patients who previously progressed on another ICI regimen appears limited. These observations should be validated in larger cohorts, as it is anticipated that this clinical scenario will become more common in the future.