CTLA4 and breast cancer: A pilot trial of durvalumab (an anti-PD-L1) and tremelimumab (an anti-CTLA-4) in metastatic BC observed an ORR of 17% in ER+ patients, but an ORR of 43% in patients TNBC, suggesting that patients with TNBC may be better candidates for this type of treatment [83].