Dr Hilton on the Impact of Trastuzumab Deruxtecan in HER2+ Breast Cancer

Christie J. Hilton, DO, assistant professor, Department of Medicine, Drexel University College of Medicine, director, Academic Breast Oncology, Allegheny Health Network (AHN), AHN Cancer Institute, discusses the impact of fam-trastuzumab deruxtecan-nxki (Enhertu) on the treatment of patients with HER2-positive metastatic breast cancer and ongoing research with the agent in this patient population.

Although the standard-of-care first-line regimen of the combination of trastuzumab (Herceptin), pertuzumab (Perjeta), and chemotherapy has remained largely unchanged, other developments have altered the treatment landscape in later lines for patients with HER2-positive metastatic breast cancer, Hilton says.

In the second-line setting, trastuzumab deruxtecan has replaced ado-trastuzumab emtansine (T-DM1; Kadcyla) as the standard of care, Hilton expands. In the phase 3 DESTINY-Breast03 trial (NCT03529110), which supported the FDA approval of trastuzumab deruxtecan in this setting, trastuzumab deruxtecan elicited significant improvements in progression-free survival compared with T-DM1. Based on these findings, trastuzumab deruxtecan became the new standard of care in the second-line setting; however, T-DM1 still has a role in the treatment armamentarium, Hilton notes.

Ongoing and future investigations will continue to explore the use of trastuzumab deruxtecan in additional settings, Hilton continues. The phase 3 DESTINY-Breast05 trial (NCT04622319) is evaluating trastuzumab deruxtecan vs T-DM1 in patients at a high-risk for recurrence who did not achieve a complete response following neoadjuvant treatment. Findings from this study could increase understanding of whether this approach could improve outcomes for patients with residual disease, Hilton concludes.