Journal: NPJ breast cancer
This multicenter real-world study assessed trastuzumab deruxtecan (T-DXd) in 64 patients with HR-negative, HER2-low metastatic breast cancer after a median of 3 prior therapy lines.
Key outcomes included:
- Objective response rate: 35.9%
- Disease control rate: 75%
- Median progression-free survival: 5.0 months
- Median overall survival: 14.9 months
Brain metastases and prior Trop-2 ADC treatment were independently associated with shorter progression-free survival.
Common adverse events included nausea, fatigue, anorexia, and neutropenia. Grade 3/4 events were mainly neutropenia, thrombocytopenia, and nausea.
Patients with BRCA1 mutations or MYC amplifications showed lower response rates, but these differences were not statistically significant.
The study supports the efficacy and manageable safety of T-DXd, highlighting potential resistance biomarkers and high-risk subgroups for treatment consideration.