eligibility_summary
Include: adults 18–75 with untreated gastric/GEJ (non‑Siewert I) adenocarcinoma, pMMR/MSS, HER2 known, ECOG 0–1, measurable disease, fit for chemo/anti‑PD‑1/RT/surgery. Limited mets only: RPLN or single organ (liver ≤5 in one lobe, unilateral lung, ovary w/o carcinomatosis, adrenal, extra‑abd nodes, local bone), P0. Exclude: prior therapy, pregnancy, recent cancer, prior checkpoint/immunosuppression/live vaccine, major comorbidity, organ/CNS disease, bleeding/obstruction, DPD deficiency, active HIV/HBV/HCV.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Trial tests multimodal therapy for limited metastatic gastric/GEJ adenocarcinoma: hypofractionated radiotherapy (HFRT/SBRT) + systemic chemotherapy + anti‑PD‑1 monoclonal antibody, with surgery/metastasectomy afterward (or RFA/MWA if inoperable). HER2+ patients also receive trastuzumab, adjuvant PD‑1 mAb maintained up to 1 year post‑op. Mechanisms/types: • Anti‑PD‑1 mAbs (e.g., nivolumab, pembrolizumab, IgG4 antibodies) block the PD‑1/PD‑L1 checkpoint to reinvigorate exhausted T cells and restore antitumor cytotoxicity. Targets: PD‑1 pathway on T cells/tumor microenvironment. • Trastuzumab (IgG1 mAb) binds HER2/ERBB2, inhibits MAPK/PI3K signaling and mediates ADCC. Targets: HER2‑overexpressing tumor cells and FcγR‑bearing immune cells. • Chemotherapy: fluoropyrimidines (S‑1, capecitabine, 5‑FU, antimetabolites inhibiting thymidylate synthase/DNA-RNA synthesis), oxaliplatin (platinum DNA crosslinker), leucovorin (enhances 5‑FU). Targets: rapidly dividing tumor cells/DNA synthesis. • HFRT/SBRT and RFA/MWA induce DNA damage/thermal necrosis and immunogenic tumor cell death.