Multinational phase 1b study of cabozantinib plus atezolizumab for locally advanced or metastatic urothelial carcinoma

The multinational phase 1b COSMIC-021 evaluates the combination of cabozantinib and atezolizumab in advanced solid tumors. Patients with locally advanced or metastatic urothelial carcinoma were included in four cohorts: first-line cisplatin-eligible, first-line cisplatin-ineligible, previous platinum-containing chemotherapy treated, and previous ICI-treated. Patients received oral cabozantinib 40 mg once daily and intravenous atezolizumab 1,200 mg once every three weeks. This figure shows the response to treatment and this figure shows survival outcomes. Grade 3 or 4 treatment-related adverse events were experienced by 43%, 67%, 57%, and 45% of patients in the four groups, and discontinuation due to TRAEs by 17%, 13%, 3%, and 19%. There were no grade 5 TRAEs. The authors conclude that the combination of cabozantinib plus atezolizumab exhibited clincical activity in advanced urothelial carcinoma that is cisplatin-eligible, cisplatin-ineligible, or previously treated with platinum-containing chemotherapy, whereas clinical activity in the previous ICI-treated cohort was modest.