eligibility_summary
Eligible: patients with HER2-positive metastatic breast cancer, pre- or postmenopausal, previously treated with anti-HER2 therapy, and maintaining complete or partial response for over 2 years. Exclude: patients considered inappropriate for research at physician’s discretion, such as those who may receive unsuitable treatment.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Study: Observational evaluation of personalized ctDNA (Signatera) to monitor MRD in HER2+ metastatic breast cancer patients with ≥2-year durable response, comparing those continuing vs stopping anti-HER2 therapy. Interventions/mechanisms (drug types): Trastuzumab (monoclonal antibody to HER2/ERBB2 domain IV, blocks signaling and mediates ADCC), Pertuzumab (monoclonal antibody to HER2 domain II, blocks HER2–HER3 dimerization), T-DM1/ado-trastuzumab emtansine (HER2-targeted ADC delivering DM1 microtubule inhibitor), and T-DXd/trastuzumab deruxtecan (HER2-targeted ADC delivering a topoisomerase I inhibitor with bystander effect). Targets/pathways: HER2-overexpressing tumor cells, HER2–HER3/PI3K–AKT/MAPK signaling, immune effector (ADCC). Signatera targets circulating tumor DNA to detect MRD.