eligibility_summary
Adults ≥18 with untreated, locally advanced unresectable or metastatic HER2+ (IHC3+ or IHC2+ with ISH/FISH+) gastric/GEJ adenocarcinoma, measurable disease per RECIST v1.1 (not bone-only), ECOG 0–1, life expectancy ≥6 mo, adequate organ function. Exclude: other cancer within 2 yrs, progression ≤6 mo after neoadjuvant/adjuvant therapy, prior HER2 therapy, active GI bleed, CNS mets, LVEF <55%, severe mAb allergy.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Phase III double-blind RCT in first-line HER2+ gastric/GEJ adenocarcinoma testing HLX22 + trastuzumab + XELOX vs trastuzumab + XELOX ± pembrolizumab. Interventions and mechanisms: • HLX22: recombinant humanized anti‑HER2 monoclonal antibody (biologic) that binds HER2 on tumor cells, adds HER2 pathway blockade, and promotes antibody‑dependent cellular cytotoxicity (ADCC). • Trastuzumab: humanized IgG1 anti‑HER2 mAb, inhibits HER2 signaling and mediates ADCC. • Pembrolizumab: humanized IgG4 anti‑PD‑1 checkpoint inhibitor, restores T‑cell activity by blocking PD‑1/PD‑L1/PD‑L2 interactions. • XELOX: oxaliplatin (platinum DNA crosslinker) plus capecitabine (oral 5‑FU prodrug inhibiting thymidylate synthase). Targeted cells/pathways: HER2/ERBB2 on tumor cells with downstream PI3K/AKT/MAPK, PD‑1 on T cells (tumor microenvironment), rapidly dividing cells’ DNA synthesis/repair, Fcγ‑mediated NK‑cell ADCC.