For example, in the KEYNOTE-028 study, single-agent pembrolizumab exhibited modest activity (objective response rate, ORR = 12%) in a subset of patients with PD-L1-positive, HR+, HER2− MBC11; yet in the SPY2 trial, pembrolizumab combined with neoadjuvant chemotherapy in early HER2− breast cancer resulted in significantly higher predicted pCR rate in both HR+ disease and TNBC compared with chemotherapy alone12. Here, ERBB2 is linked to breast cancer.