eligibility_summary
Eligible: adults (>18) with advanced, HR‑negative (ER≤10%), HER2‑low (IHC 1+ or 2+/FISH−) breast cancer, previously treated with ≥1 dose of trastuzumab‑deruxtecan for incurable disease as ≥2nd line, no active CNS mets (if present, must be stable, asymptomatic, and without CNS‑directed therapy ≥6 months). Exclude: prior T‑DXd in neoadjuvant/adjuvant/other cancers, other active malignancies (except non‑melanoma skin), serious non‑oncologic lung disease, concurrent breast tumor with different receptors.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Trial type: retrospective, observational real‑world study in Brazil (terminated for strategic reasons) evaluating trastuzumab deruxtecan (T‑DXd) in metastatic triple‑negative, HER2‑low breast cancer. Intervention/drug: Trastuzumab deruxtecan (ADC, humanized anti‑HER2 monoclonal antibody linked via a cleavable linker to deruxtecan, a topoisomerase I inhibitor). Mechanism: Antibody binds HER2 on tumor cells (even low expression), is internalized, linker is cleaved in lysosomes, releasing deruxtecan to inhibit topoisomerase I, causing DNA damage and apoptosis, payload’s membrane permeability supports a “bystander” effect, Fc may mediate ADCC. Targets: HER2‑low breast cancer cells (IHC 1+ or 2+/ISH‑negative). Pathways: HER2 receptor–mediated endocytosis/signaling and DNA replication/repair via topoisomerase I.