Dr. Krop on Evaluating De-Escalated Treatment Strategies in HER2+ Breast Cancer

Ian E. Krop, MD, PhD, associate chief, Division of Breast Oncology, Susan F. Smith Center for Women’s Cancers, clinical research director, Breast Oncology Center, senior physician, Dana-Farber Cancer Institute, associate professor of medicine, Harvard Medical School, discusses the need to evaluate de-escalated treatment strategies in HER2-positive breast cancer.

Currently, most patients with early-stage HER2-positive breast cancer are being cured of their disease, Krop explains. Randomized trials such as the phase 3 APHINITY (NCT01358877) and KAITLIN (NCT01966471) trials are demonstrated invasive disease-free survival (iDFS) rates of over 90% at 3 years in patients with early-stage, high-risk disease. For example, updated results from the APHINITY trial, which were published in the Journal of Clinical Oncology in 2021, demonstrated that at 6 years of follow-up, patients with node-positive, HER2-positive, early-stage breast cancer had improved iDFS with pertuzumab (Perjeta) plus standard adjuvant therapy vs placebo plus standard adjuvant therapy.

However, these data suggest that many patients with early-stage disease are being overtreated, Krop explains. Findings from the phase 2 APT trial (NCT00542451) showed that patients with stage I disease had good outcomes with trastuzumab (Herceptin) and paclitaxel, which is less toxic than the standard regimens of docetaxel, carboplatin, and trastuzumab or doxorubicin, cyclophosphamide, paclitaxel, and trastuzumab. Further studies will likely build upon those data, Krop concludes.