Dr. Tkaczuk on the Utilization of Trastuzumab Deruxtecan in HER2+ Breast Cancer

Katherine Tkaczuk, MD, director, the Breast Evaluation and Treatment Program, the University of Maryland School of Medicine, Marlene and Stewart Greenebaum Cancer Center, discusses the utilization of fam-trastuzumab deruxtecan-nxki (Enhertu) in HER2-positive breast cancer.

The DESTINY-Breast03 trial (NCT03529110) compared the antitumor activity, safety, and efficacy of trastuzumab deruxtecan vs trastuzumab emtansine (T-DM1; Kadcyla) in patients with HER2-positive, metastatic breast cancer.

Previously published data from the trial showed that trastuzumab deruxtecan demonstrated a significant improvement in the progression-free survival compared with T-DM1, Tkaczuk explains, adding that patients in the experimental arm also achieved an improved overall response rate compared with the control arm, Tkaczuk adds.

In May 2022, the FDA granted regular approval to trastuzumab deruxtecan for adult patients with unresectable or metastatic HER2-positive breast cancer who have previously received an anti–HER2-based regimen either in the metastatic setting, or in the neoadjuvant or adjuvant setting, and have developed disease recurrence during or within 6 months of therapy completion, based on data from DESTINY-Breast03.

Patients with breast cancer are considered HER2-positive if they have an immunohistochemistry score of 3+, or 2+ by IHC/fluorescence in situ hybridization, Tkaczuk concludes.