T-DXd in ER+/HER2-Low Breast Cancer: Insights From DESTINY-Breast06

Aditya Bardia, MD, MPH, FASCO, professor, department of medicine, division of hematology/oncology, director of translational research integration, UCLA Health Jonsson Comprehensive Cancer Center, Los Angeles, CA, discusses how fam-trastuzumab deruxtecan-nxki (T-DXd; Enhertu) compares with physician’s choice of chemotherapy in estrogen receptor (ER)-positive/HER2-low breast cancer and how progression speed may influence a clinicians treatment choice between the two.

Bardia then covers some of the safety outcomes observed in the DESTINY-Breast06 trial (NCT04494425) and explains what oncologists should take away from the study’s updated findings presented at the 2024 SABCS.

Transcription:

0:09 | T-DXd is a HER2-directed antibody-drug conjugate that demonstrated superiority over standard chemotherapy just after endocrine-based therapy. So, pretty much first-line therapy after endocrine-based therapy in the DESTINY-Breast06 study showed improvement in progression-free survival, and much higher response rate as well. If we look at a subgroup of patients who had rapid disease progression on first-line therapy, even in this subgroup as presented at SABCS 2024, T-DXd was superior to standard chemotherapy.

0:43 | Important [adverse] effects to remember with T-DXd, which is seen in DESTINY-Breast06, as well as other studies, include nausea, myelosuppression, but also a serious [adverse] effect is pneumonitis, grade 4. Grade 4 pneumonitis is rare, but has been seen in clinical trials. So, physicians should be aware of pneumonitis, identify pneumonitis early, and intervene early.

1:08 | T-DXd is a potential option. In ER-positive, metastatic breast cancer, whenever you are thinking of chemotherapy for a patient, that is where potentially T-DXd is an option, as seen in the DESTINY-Breast06 study.

REFERENCE:

Bardia A. Efficacy and safety of trastuzumab deruxtecan (T-DXd) vs physician’s choice of chemotherapy (TPC) by pace of disease progression on prior endocrine-based therapy: additional analysis from DESTINY-Breast06. Presented at the 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, TX. LB1-04.