Neoadjuvant Therapy with Trastuzumab Emtansine for HER2-Positive Breast Cancer

Chemotherapy with dual HER2-targeting agents (e.g., pertuzumab, trastuzumab) is considered optimal neoadjuvant therapy for patients with operable HER2-positive breast cancer. Several clinical trials of this strategy have reported consistently high rates of pathologic complete response (pCR) at the time of surgery; patients achieving pCR tend to have better long-term clinical outcomes than those who do not. Trastuzumab emtansine (T-DM1) is an antibody drug conjugate approved for use in the metastatic disease setting, as well in patients with residual disease following preoperative HER2-directed therapy.

In PREDIX HER2, an open-label, randomized phase 2 trial, 202 patients with HER2-positive tumors were randomized to standard preoperative ther…