This is a Phase III, 3-armed randomized clinical trial that includes both cisplatin eligible and ineligible patients with locally advanced or metastatic urothelial cancer and ECOG performance status < 2. The trial compares in a 1:1:1 randomization single agent atezolizumab alone to platinum-based combination chemotherapy with gemcitabine and cisplatin or carboplatin plus atezolizumab versus chemotherapy alone with gemcitabine and cisplatin or carboplatin and placebo.
With the approvals of checkpoint inhibitors for urothelial cancer it has become of interest to assess the PD-L1 checkpoint inhibitor, atezolizumab, versus the combination of platin-based chemotherapy and a checkpoint inhibitor versus chemotherapy alone in the front line setting in both cisplatin eligible and ineligible patients.
PFS, OS and safety
This trial follows on the heels of the successful Phase II IMvigor 210 trial with atezolizumab in the first line setting in cisplatin ineligible patients (cohort 1) and IMvigor 210 (cohort 2) in patients who had failed prior platinum based chemotherapy (1-3). IMvigor 211, the phase III study in second line compared to chemotherapy did not meet its primary endpoint of an improvement in overall survival, in part due to the design of the study which relied heavily on PD-L1 status (4).