Is trastuzumab deruxtecan better than chemotherapy for HR-positive breast cancer?
Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate that targets HER2. For patients with hormone receptor (HR)-positive, HER2-low metastatic breast cancer, T-DXd has shown better progression-free survival (PFS) than standard chemotherapy in the DESTINY-Breast06 trial 4. However, this benefit is specific to HER2-low tumors, and overall survival results are still awaited. For HR-positive, HER2-negative tumors that are not HER2-low, other ADCs like datopotamab deruxtecan have not shown an overall survival benefit over chemotherapy 1.
What the research says
Immunotherapy has also been studied in HR-positive breast cancer. A meta-analysis of 11 trials found that immunotherapy did not improve overall response rate compared to control, though it did increase complete response rates 3. However, immunotherapy was associated with more side effects 3. These results suggest that for most HR-positive patients, immunotherapy is not a clear replacement for chemotherapy.
What to ask your doctor
- Is my tumor HER2-low or HER2-ultralow, and would I be eligible for trastuzumab deruxtecan?
- What are the potential side effects of trastuzumab deruxtecan compared to standard chemotherapy?
- How does my prior treatment history (e.g., time on CDK4/6 inhibitors) affect the expected benefit of T-DXd?
- Are there ongoing clinical trials comparing T-DXd with other treatments for my specific breast cancer subtype?
- What is the role of overall survival data in making this treatment decision, and is that information available for T-DXd?
This question is drawn from common patient questions about Oncology and answered using cited medical research. We do not provide individualized advice.