New combo aims to turn inoperable stomach cancer into operable disease

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18-75 years at the time of enrollment, with an estimated life expectancy of ≥ 3 months. * Histologically or cytologically confirmed gastric cancer or gastroesophageal junction cancer, predominantly adenocarcinoma. * Unresectable locally advanced gastric or gastroesophageal junction adenocarcinoma (Stage III or IV), as determined by the investigator based on CT, MRI, and/or PET-CT. * Disease with conversion (translational) therapeutic potential, as assessed by the investigator. * No prior anti-tumor treatment, including chemotherapy, radiotherapy, targeted therapy, immunotherapy, or other systemic anticancer therapies. * Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. * Adequate hematologic function within 14 days prior to enrollment: * White blood cell count ≥ 3.5 × 10⁹/L. * Absolute neutrophil count ≥ 1.5 × 10⁹/L. * Hemoglobin ≥ 90 g/L (9.0 g/dL). * Platelet count ≥ 100 × 10⁹/L. * Adequate hepatic function within 14 days prior to enrollment:Total bilirubin ≤ 1.5 × upper limit of normal (ULN);ALT and AST ≤ 2.5 × ULN in patients without liver metastases;ALT and AST ≤ 5 × ULN in patients with liver metastases;Adequate renal function:Serum creatinine ≤ 1.5 × ULN;Women of childbearing potential must have a negative serum or urine pregnancy test within 7 days prior to enrollment and agree to use effective contraception during the study and for at least 12 weeks after the last dose. * Male participants must be surgically sterile or agree to use effective contraception during the study and for at least 12 weeks after the last dose * Ability to understand and willingness to sign a written informed consent form * Expected to comply with study procedures and follow-up requirements Exclusion Criteria: * HER2-positive gastric or gastroesophageal junction adenocarcinoma. * Conditions that may significantly affect oral drug absorption, including inability to swallow, persistent nausea or vomiting, chronic diarrhea, or intestinal obstruction. * Known hypersensitivity or allergy to adebrelimab, apatinib, oxaliplatin, S-1 (tegafur/gimeracil/oteracil), or any of their excipients. * History of severe allergic reactions to monoclonal antibodies. * Active autoimmune disease or autoimmune disorders requiring systemic treatment. * Congenital or acquired immunodeficiency. * Use of systemic immunosuppressive therapy within 14 days prior to the first dose of study treatment. * Administration of live attenuated vaccines within 4 weeks prior to the first dose or planned during the study period. * Severe infection within 4 weeks prior to initiation of study treatment. * History of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation. * Evidence of interstitial lung disease, including pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radiation pneumonitis, drug-induced pneumonitis, or severely impaired pulmonary function. * Uncontrolled hypertension despite at least 3 months of antihypertensive treatment. * Uncontrolled clinically significant cardiovascular disease. * High risk of severe bleeding, as judged by the investigator. * Peripheral neuropathy of Grade \> 2 according to CTCAE. * Participation in another interventional clinical trial within 4 weeks prior to enrollment or within 5 half-lives of the investigational product, whichever is longer. * Any condition that, in the investigator's judgment, makes the participant unsuitable for study participation.