A combination approach with pembrolizumab, an anti-PD1 antibody, in association with anastrozole, exemestane, or letrozole (in the ER-positive cohort of the study) is being evaluated in patients with ER-positive metastatic breast cancer (NCT02648477), and neoadjuvant durvalumab, an anti-PDL1 antibody, is being explored in a phase II trial (ULTIMATE, NCT02997995) in combination with exemestane in patients whose tumor is found inflamed (i.e., > 10% CD8+ T cells) after 3 weeks of exemestane with tremelimumab, an anti-CTLA4 antibody. Here, CTLA4 is linked to neoplasm.