Dr Hamilton: ASCO 2025 Breast Cancer Breakthroughs

Erika Hamilton, MD, director of breast cancer research at Sarah Cannon Research Institute, shares key insights from the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting that are set to impact breast cancer treatment.

A prominent theme, which Hamilton calls "moving on up," involves bringing antibody-drug conjugates (ADCs) into earlier lines of therapy. She first highlights DESTINY-Breast09 (NCT04784715).

“I think ASCO 2025 was really exciting for breast. We had quite a few big presentations. One of the themes, as I like to call it, is moving on up, or moving some of these antibody-drug conjugates into earlier lines. This was the theme of DESTINY-Breast09,” Hamilton explains.

This trial investigated fam-trastuzumab deruxtecan-nxki (T-DXd; Enhertu) in the first-line setting for HER2-positive metastatic breast cancer, showing a significant progression-free survival (PFS) benefit of over 13 months. This could shift the current second-line approval to earlier use.

She also shares data on sacituzumab govitecan (Trodelvy) with pembrolizumab (Keytruda) in first-line, PD-L1 positive triple-negative breast cancer. This combination also demonstrated a significant increase in PFS compared with chemotherapy/pembrolizumab.

Hamilton also discusses SERENA-6 (NCT04964934). This study explored changing treatment based on the emergence of the ESR1 resistance mechanism. While it serves as a "proof of principle" for tailoring therapy to resistance, she notes that incorporating this into practice is still being determined. The long-term benefit for patients, particularly regarding PFS2 and overall quality of life, remains crucial, and the data is still maturing.

“PFS2 is really important here. So saying, of course, we use another line of therapy, but are we really benefiting these patients over the long term in terms of them living longer or not developing pain or liver mets or something that is going to make their quality of life better? And that data in SERENA-6 is still a little bit immature,” adds Hamilton.