Several clinical trials have evaluated the use of dual HER2 blockade in early-stage HER2-positive breast cancer in the absence of chemotherapy.8, 9, 10, 11, 12, 13, 14 The first trial (i.e., TBCRC-006) was reported by Rimawi and colleagues8 in 2013. This evidence concerns the gene ERBB2 and breast carcinoma.