LBA24 Cabozantinib (C) in combination with atezolizumab (A) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC): Results of expanded cohort 6 of the COSMIC-021 study

C may enhance response to immune checkpoint inhibitors by promoting an immune-permissive microenvironment. COSMIC-021 (NCT03170960), a multinational phase 1b study, is evaluating C + A in solid tumors, including mCRPC, which has limited treatment options after failure of novel hormonal therapy (NHT). We report efficacy and safety results of expanded cohort 6 in mCRPC.