Dr. Sammons on the Clinical Implications of DESTINY-Breast03 in HER2+ Breast Cancer

Sarah Sammons, MD, assistant professor of medicine, Department of Medicine, Duke University School of Medicine, member, Duke Cancer Institute, Duke Health, discusses the clinical implications of the phase 3 DESTINY-Breast03 trial (NCT03529110) in HER2-positive breast cancer.

The topline results of the randomized DESTINY-Breast03 trial demonstrated a clinically meaningful and statistically significant improvement in progression-free survival (PFS) with fam-trastuzumab deruxtecan-nxki (Enhertu) vs ado-trastuzumab emtansine (T-DM1; Kadcyla) in patients with HER2-positive metastatic breast cancer. By blinded-independent review, the median PFS was not reached with trastuzumab deruxtecan vs 6.8 months with T-DM1. By investigator assessment, the median PFS was 25.1 months vs 7.2 months, respectively.

Although the overall survival data were immature at the time of the data presentation, the data represent a paradigm shift in the second-line setting for patients with HER2-positive breast cancer, Sammons explains.

Additionally, patients with brain metastases had a median PFS of 15 months with trastuzumab deruxtecan vs 5.7 months with T-DM1. As such, trastuzumab deruxtecan should be considered a standard second-line option for patients with stable brain metastases, Sammons concludes.