Hurvitz SA, et al. - In this work, researchers reported 3-year outcomes from KRISTINE study that demonstrated the achievement of a lower pathologic complete response rate (44.4% v 55.7%), but with fewer grade 3 or greater and serious adverse events (AEs) with neoadjuvant trastuzumab emtansine plus pertuzumab (T-DM1+P) vs docetaxel, carboplatin, trastuzumab plus P (TCH+P) for the treatment human epidermal growth factor receptor 2–positive stage II to III breast cancer. Random assignment of 444 patients was done (T-DM1+P, n = 223; TCH+P, n = 221). A higher risk of event-free survival event was noted with T-DM1+P vs TCH+P, owing to locoregional progression events before surgery. An invasive disease-free survival event was similar, grade 3 or greater AEs during neoadjuvant treatment were fewer, and adverse events leading to treatment discontinuation during adjuvant treatment were more with T-DM1+P vs TCH+P.