Neoadjuvant T-DM1 Shows Promising pCR Rates in HER2+/HR+ Early Breast Cancer

“Chemotherapy-free neoadjuvant treatment with trastuzumab emtansine (T-DM1; Kadcyla) demonstrated a pathological complete response (pCR) rate of 40.5% in patients with HER2+ and HR+ early breast cancer, according to findings from the phase II ADAPT trial presented at the 2015 ASCO Annual Meeting.

” ‘After 12 weeks without systemic chemotherapies we observed more than a 40% pCR in both the breast and nodes in our T-DM1-treated HER+/HR+ patients,’ said lead investigator Nadia Harbeck, MD, PhD, head of the Breast Center, Oncological Therapy and Clinical Trials Unit, University of Munich, Germany. ‘We did see very low overall toxicity, and did not detect any new safety signals.’

“The ADAPT trial is a large umbrella trial that has enrolled 5000 patients with various breast cancer phenotypes. In the arm of the trial presented at ASCO, 376 patients with HER2+ and HR+ breast cancer were randomized to receive neoadjuvant T-DM1 at 3.6 mg/kg with or without endocrine therapy or trastuzumab plus endocrine therapy. Treatment was administered for 4 cycles followed by surgery and 1-year of standard adjuvant chemotherapy plus trastuzumab.”