eligibility_summary
Eligibility: adults (≥18) with pathology-confirmed unresectable/metastatic breast cancer starting T-DXd per China label (new start or ≤14 days since first dose), able to consent. Cohort A: HER2+ (IHC3+ or 2+/ISH+), ≥1 prior anti-HER2, ≤2 metastatic lines. Cohort B: HER2-low (IHC1+ or 2+/ISH−), prior metastatic therapy or relapse ≤6 mo post-adjuvant chemo, ≤2 metastatic chemo lines. Exclude: pregnancy/breastfeeding, blinded trials, T-DXd allergy, or unfit.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Study: Prospective observational (China) assessing real‑world effectiveness/safety of trastuzumab deruxtecan (T-DXd) in unresectable/metastatic HER2+ or HER2‑low breast cancer after prior therapy. Drug/intervention: T-DXd, an IV antibody–drug conjugate (anti-HER2 monoclonal antibody trastuzumab linked via a cleavable linker to deruxtecan [DXd], a topoisomerase I inhibitor). Mechanism: Binds HER2 (ERBB2) on tumor cells—including HER2‑low—then internalizes, lysosomal cleavage releases DXd, inhibiting topoisomerase I to cause DNA damage and apoptosis. Retains trastuzumab functions (partial HER2 signaling blockade, Fc-mediated ADCC). Membrane-permeable payload enables bystander killing. Targets: HER2-expressing breast cancer cells, pathways include HER2/ERBB2 signaling and DNA replication/repair via topoisomerase I.