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

Sara A. Hurvitz, MD, associate professor, David Geffen School of Medicine, University of California, Los Angeles (UCLA), medical oncologist, medical director, Jonsson Comprehensive Cancer Center Clinical Research Unit, co-director, Santa Monica-UCLA Outpatient Oncology Practices, director, Breast Cancer Clinical Trials Program, UCLA, discusses the clinical implications of the phase 3 DESTINY-Breast03 trial (NCT03529110) in HER2-positive breast cancer.

During the 2021 San Antonio Breast Cancer Symposium, updated results from exploratory subgroup analyses of the DESTINY-Breast03 trial were presented and demonstrated a progression-free survival (PFS) and overall response rate (ORR) improvement with fam-trastuzumab deruxtecan-nxki (Enhertu) vs ado-trastuzumab emtansine (T-DM1; Kadcyla) across patients with HER2-positive metastatic breast cancer who received prior trastuzumab (Herceptin) and a taxane. The benefits were observed irrespective of hormone receptor status, prior pertuzumab (Perjeta), number of prior lines of therapy, and presence or absence of visceral disease. Moreover, patients with baseline brain metastases also derived a PFS and ORR benefit with trastuzumab deruxtecan vs T-DM1.

As such, these data support the use of trastuzumab deruxtecan in the second-line setting instead of T-DM1, Hurvitz explains. The confirmatory DESTINY-Breast02 study (NCT03523585) is further evaluating the use of trastuzumab deruxtecan compared with investigator’s choice of lapatinib (Tykerb) or trastuzumab/capecitabine in patients with HER2-positive breast cancer who were previously treated with T-DM1. Additionally, trastuzumab deruxtecan is being evaluated in the first-line setting for patients with active brain metastases, Hurvitz concludes.