ERBB2 and breast carcinoma: The pCR rate in unselected patients with HR+HER2– early-stage breast cancer in the first PD-1 inhibitor arm of the trial, pembrolizumab/paclitaxel followed by preoperative AC, was 30%, compared with 13% in concurrent controls.7 Stratified by ImPrint, pCR rates were 77% in ImPrint+ versus 7% in ImPrint– (OR, 35; P = 1.8E-05; Figs 2B-2D).