eligibility_summary
Adult females 18–70 with metastatic, unresectable breast cancer, ER/PR ≥10% and HER2‑low (IHC 1+ or 2+ with negative FISH), prior endocrine therapy, measurable disease per RECIST v1.1 or osteolytic bone‑only, stable/asymptomatic brain mets allowed, ECOG ≤2, ≥3‑mo survival, toxicities ≤grade 1, adequate labs and cardiac (LVEF ≥55, QTcF ≤470), consent. Exclude recent (<2 wks) therapy/surgery, serious cardio/cerebrovascular disease, active autoimmune, neuro/psychiatric disorders, major comorbidity, DV allergy, poor compliance.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Trial NCT05904964 tests disitamab vedotin (RC48) vs physician’s-choice endocrine therapy in HR+/HER2-low metastatic breast cancer. Disitamab vedotin is an antibody–drug conjugate (ADC): a humanized anti-HER2 IgG linked via a cleavable linker to MMAE, a microtubule-disrupting cytotoxic payload. Mechanism: binds HER2 on tumor cells (including low expressors), internalizes, then releases MMAE to inhibit tubulin polymerization, causing mitotic arrest/apoptosis and potential bystander killing. Endocrine therapy inhibits ER signaling via ER antagonism/degradation (SERMs/SERDs) or estrogen depletion (aromatase inhibitors). Targets/pathways: HER2 receptor, microtubules, estrogen receptor pathway.