ASCO 2017: Adding a Second HER2 Blocker to Standard of Care in Invasive Breast Cancer
For women with HER2-positive early-stage breast cancer, the addition of pertuzumab to the standard of care trastuzumab after surgery may lower the chance of invasive breast cancer, according to the results of the phase III APHINITY clinical trial, presented by Gunter von Minckwitz, MD, PhD, at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract LBA500).
“Our early findings suggest we may be able to further improve outcomes for some women by adding a second HER2-targeted treatment without increasing the risk for serious side effects,” said Dr. von Minckwitz, President of the German Breast Group in Neu-Isenburg, Germany.
In the study, a total of 4,805 women with adequately excised HER2-positive breast cancer were randomly assigned to receive standard adjuvant chemotherapy for 18 weeks plus 1 year of either trastuzumab and pertuzumab or trastuzumab and placebo. Patients who received the second HER2-targeted agent along with trastuzumab had a 19% lower chance of developing invasive breast cancer than those who received trastuzumab alone.
About 8% of all patients diagnosed with breast cancer have early HER2-positive disease, the investigators estimated. They suggest this regimen with a second HER2-targeted agent may be of benefit for some of these women, primarily those with the highest risk (node-positive and hormone receptor–negative breast cancer).