Dr Han on the Significance of Trastuzumab Deruxtecan in HER2-Low Breast Cancer

Heather Han, MD, research director, medical oncologist, Department of Breast Oncology, Moffitt Cancer Center, discusses breakthrough data from the phase 3 DESTINY-Breast04 trial (NCT03734029).

This trial, which investigated fam-trastuzumab deruxtecan-nxki (Enhertu) vs physician’s choice of chemotherapy in HER2-low metastatic breast cancer, defined HER2-low as a new subset of breast cancer, creating new options for patients with an immunohistochemistry score of 1+ or 2+, who were historically considered HER2-negative, Han says. Trastuzumab deruxtecan showed improved progression-free survival (PFS) and overall survival (OS) in this patient population, Han explained. The median PFS was 9.9 months in all patients treated with trastuzumab deruxtecan vs 5.1 months with physician’s choice of chemotherapy, and the median OS was 23.4 months in all patients treated with trastuzumab deruxtecan vs 16.8 months with physician’s choice of chemotherapy.

In defining HER2-low as a new breast cancer subset, almost half of patients with metastatic breast cancer, including those with hormone receptor–positive or triple-negative disease, now have a more effective treatment, Han notes. Trastuzumab deruxtecan will help many patients with newly defined HER2-low disease live longer, Han concludes.