Revisiting the old and enhancing with the new might describe the range of results in HER2+ breast cancer studies to be presented at the upcoming San Antonio Breast Cancer Symposium, which will be held Dec. 4-8 in San Antonio.
Since 2005, 12 months of trastuzumab added to chemotherapy alone has been the standard of care in patients with HER2-positive early breast cancer. PHARE (Protocol for Herceptin as Adjuvant Therapy With Reduced Exposure) was the first trial evaluating a reduced schedule of trastuzumab, a noninferiority trial comparing 6 with 12 months of adjuvant trastuzumab. Results published in 2013 in Lancet Oncology demonstrated a failure to prove that 6 months of treatment was non-inferior to 12 months. The final analysis of PHARE will be presented on Wednesday at SABCS 2018 by Xavier Pivot, MD, PhD, of Paul-Strauss Cancer Centre, Université de Strasbourg (France).
In a more recent study, trastuzumab emtansine (T-DM1) was pitted against trastuzumab as adjuvant therapy in patients with HER2-positive early breast cancer with residual invasive disease after neoadjuvant chemotherapy and HER2-targeted therapy including trastuzumab. The primary results of the phase 3 study (KATHERINE) will be presented by Charles E. Geyer, MD, of Virginia Commonwealth University and the Massey Cancer Center, both in Richmond.
As for the new, KATE2 is a phase 2 randomized trial evaluating the addition of checkpoint inhibitor atezolizumab to T-DM1 for patients with locally advanced or metastatic HER2-positive breast cancer who received prior trastuzumab and taxane-based therapy. Results will be presented by Leisha A. Emens, MD, PhD, professor at the University of Pittsburgh and director of translational immunotherapy for the Women’s Cancer Research Center there.