2025 MLS Nashville | HER2 Positive Breast Cancer Updates in 2025

Overview

Dr. O’Shaughnessy highlighted that adding T-DXd to pertuzumab in metastatic HER2-positive breast cancer extended median PFS by 13.8 months versus the Cleopatra regimen (44% lower risk of progression or death), with DESTINY-Breast09 also showing marked PFS gains in PI3K-mutant tumors. In the neoadjuvant setting, four cycles of preoperative THP yielded a 43% pathologic complete response—weekly paclitaxel outperforming docetaxel—and the ongoing DESTINY-Breast11 trial may reshape treatment for higher-risk patients, though the ideal THP duration remains unclear.