DESTINY-Breast06 and A-BRAVE: Advances in Breast Cancer Research

Dr. Allison Zibelli and Dr. Erika Hamilton discuss the results of the DESTINY-Breast06 trial in HR+, HER2-low and HER2-ultralow metastatic breast cancer and the A-BRAVE trial in early triple-negative breast cancer, the results of which were both presented at the 2024 ASCO Annual Meeting.

TRANSCRIPT

Dr. Allison Zibelli: Hello, I'm Dr. Allison Zibelli, your guest host of the ASCO Daily News Podcast. I'm an associate professor of medicine and breast medical oncologist at the Sidney Kimmel Cancer Center of Jefferson Health in Philadelphia. My guest today is Dr. Erika Hamilton, a medical oncologist and director of breast cancer research at the Sarah Cannon Research Institute. We'll be discussing the DESTINY-Breast06 trial, which showed a progression-free advantage with the antibody-drug conjugate trastuzumab deruxtecan (T-DXd) compared to chemotherapy in hormone receptor-positive HER2-low or HER2-ultralow metastatic breast cancer. We'll address the implications of this study for the community, including the importance of expanding pathology assessments to include all established subgroups with HER2 expression, and the promise of expanding eligibility for antibody-drug conjugates. We'll also highlight advances in triple-negative breast cancer, focusing on the A-BRAVE trial, the first study reporting data on an immune checkpoint inhibitor avelumab in patients with triple-negative breast cancer with invasive residual disease after neoadjuvant chemotherapy. 

Our full disclosures are available in the transcript of this episode. 

Erika, it's great to have you on the podcast today.

Dr. Erika Hamilton: Thanks so much, Allison. Happy to join.

Dr. Allison Zibelli: Antibody-drug conjugates are rapidly changing the treatment landscape in breast cancer. The data from the DESTINY-Breast06 trial suggests that trastuzumab deruxtecan may become a preferred first-line treatment option for most patients with HER2-low or HER2-ultralow metastatic breast cancer after progression on endocrine therapy. First, could you remind our listeners, what's the definition of HER2-ultralow and what were the findings of this trial?

Dr. Erika Hamilton: Yeah, those are fantastic questions. Ultralow really has never been talked about before. Ultralow is part of a subset of the IHC zeros. So it's those patients that have HER2-tumor staining that's less than 10% and incomplete but isn't absolutely zero. It's even below that +1 or +2 IHC that we have classified as HER2-low. Now, I think what's important to remember about D-B06, if you recall, D-B04 (<