eligibility_summary
Adults ≥18 with unresectable/metastatic HER2+ breast cancer, previously treated with trastuzumab and a taxane, ECOG 0–1, measurable disease (RECIST v1.1), life expectancy ≥12 weeks, consent. Exclude: prior anti‑HER2 ADC, ILD/pneumonitis needing steroids, severe hypersensitivity to antibodies/drug, recent multiple primaries (exceptions apply), uncontrolled infection/autoimmune/DM/HTN, unresolved >Grade 1 toxicity. Other criteria may apply.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Phase III, randomized, open-label study in HER2-positive unresectable/metastatic breast cancer after trastuzumab + taxane, comparing two antibody–drug conjugates (ADCs). DB-1303/BNT323: a HER2-targeted monoclonal antibody linked via a cleavable linker to a topoisomerase I inhibitor payload, binds HER2 on tumor cells, internalizes, releases payload causing DNA damage, also retains HER2 signaling blockade and ADCC. Comparator T-DM1 (trastuzumab emtansine): a HER2 ADC delivering the maytansinoid DM1 (microtubule inhibitor) via a non-cleavable linker, inhibits mitosis plus HER2 blockade/ADCC. Targets: HER2-overexpressing tumor cells, pathways include HER2/ERBB2 signaling, DNA replication (Topo I), and microtubules.