eligibility_summary
Adults ≥18 with unresectable/metastatic breast cancer (HER2+, low, or ultralow), radiologic progression, eligible and scheduled for T‑DXd per SmPC. Prior therapy: HER2+: ≥1 anti‑HER2, HR+ HER2‑low/ultralow: ≥1 metastatic endocrine and not suitable for more, HER2‑low: prior metastatic chemo or recurrence ≤6 mo post‑adjuvant. Exclude T‑DXd started >30 days pre‑enrolment, hypersensitivity, pregnancy/breastfeeding, interventional trial, other systemic cancer therapy. Consent, German/English.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Observational, real‑world study in Germany of adults with unresectable/metastatic breast cancer (HER2‑positive, HER2‑low, or HER2‑ultralow) receiving trastuzumab deruxtecan (T‑DXd, ENHERTU). 1) Drug/intervention and mechanism: T‑DXd is an antibody–drug conjugate (biologic + cytotoxic). It combines trastuzumab (humanized anti‑HER2 IgG1) with a cleavable linker to deruxtecan (DXd), a membrane‑permeable topoisomerase I inhibitor. After HER2 binding and internalization, DXd is released to inhibit Topo I, causing DNA damage and apoptosis, with a bystander effect, trastuzumab also blocks HER2 signaling and mediates ADCC. 2) Targets: HER2/ERBB2‑expressing breast cancer cells (including low/ultralow), ERBB signaling pathway, intratumoral topoisomerase I, and Fc‑dependent NK cell–mediated cytotoxicity.