QL1706 Combined With SOX Used in Theperioperative Treatment

Inclusion Criteria:

1. Sign a written informed consent to join the study voluntarily;

2. Histologically or cytologically confirmed adenocarcinoma of the stomach orgastroesophageal junction;

3. Adenocarcinoma of the stomach or gastroesophageal junction was evaluated by CT/MRI (primary clinical stage ≥T3 or N+, M0, according to AJCC 8th edition staging),including Siewert type II and III tumors

4. Age 18-75 years old, male or female;

5. ECOG PS 0-1 ;

6. Have not received any anti-tumor treatment for gastric or gastroesophageal junctionadenocarcinoma, including radiotherapy, chemotherapy, surgery, etc.;

7. Surgical treatment is planned after the completion of neoadjuvant therapy, and R0resection is expected;

8. Expected survival ≥6 months;

9. Normal functioning of major organs, including:

10. Blood routine examination (no blood component, cell growth factor are allowedwithin 7 days before the first use of the study drug) :neutrophil count ≥ 1.5×109/L Platelet count ≥ 80×109/L Hemoglobin ≥ 80 g/L

11. Blood biochemical examination:Total bilirubin ≤ 1.5 x ULN ALT ≤ 2.5 x ULN, AST ≤ 2.5 x ULN, Serum creatinine ≤ 1.5×ULN, or creatinine clearance ≥ 50 mL/min (Cocheroft-Gault formula)

12. Coagulation function: International Standardized ratio (INR) ≤ 1.5 x ULN Activated partial thromboplastintime (APTT) ≤ 1.5 x ULN

13. Fertile female subjects are required to take a serum or urine pregnancy test that isnegative within 72 hours prior to the start of the study drug administration, and touse effective contraception (such as Iuds, contraceptives, or condoms) during thetrial period and for at least 120 days after the last dose; For male subjects whosepartner is a fertile woman, they should be surgically sterilized or agree to useeffective contraception during the trial and for 120 days after the last dose;

14. The subject have good compliance and cooperated well with the follow-up

15. Agreed to provide tumor tissue samples

Exclusion Criteria:

1. There are unresectable factors, including unresectable tumor causes or unresectableor refused surgery contraindications;

2. Have received or are receiving any of the following treatment:

3. any radiation therapy, chemotherapy, or immune checkpoint inhibitors (such asanti-PD-1 antibodies, anti-PD-L1 antibodies, anti-CTLA-4 antibodies, etc.) andother anti-tumor drugs;

4. being treated with immunosuppressive drugs or systemic hormones forimmunosuppressive purposes within 2 weeks prior to the initial use of theinvestigational drug (dose >10mg/ day prednisone or equivalent); In the absenceof active autoimmune disease, inhaled or topical steroid use and adrenocorticalhormone replacement with doses >10mg/ day of prednisone or equivalent arepermitted;

5. Received live attenuated vaccine within 4 weeks prior to the first use of theinvestigational drug; If enrolled, subjects must not receive live vaccineduring the study period or within 120 days after the last administration ofQL1706;

6. Serious infections (CTCAE > Grade 2) occurred within 4 weeks prior to the first useof the study drug, such as severe pneumonia, bacteremia, and infection complicationsrequiring hospitalization; Baseline chest imaging indicated active pulmonaryinflammation, signs and symptoms of infection within 14 days prior to the first useof the study drug, or the need for oral or intravenous antibiotic treatment, exceptin cases of prophylactic antibiotic use;

7. Patients with active autoimmune disease requiring systemic treatment within 2 yearsprior to initial use of the investigational drug or a history of autoimmune diseasewith recurrence possible [including but not limited to autoimmune hepatitis,interstitial pneumonia, uveitis, enteritis, pituitaritis, vasculitis, nephritis,hyperthyroidism, hypothyroidism (which can be controlled by hormone replacementtherapy alone) Patients can be enrolled)];

8. A history of immunodeficiency, including HIV testing positive, or other acquired orcongenital immunodeficiency diseases, or a history of organ transplantation orallogeneic bone marrow transplantation;

9. There are clinical symptoms or diseases of heart that are not well controlled,including but not limited to: (1) NYHA grade II or above heart failure, (2) unstableangina pectoris, (3) myocardial infarction within 1 year, (4) Clinically significantsupraventricular or ventricular arrhythmias that are not well controlled without orafter clinical intervention; (5) QTc> 450ms (male); QTc > 470ms (female);

10. Patients found to have active pulmonary tuberculosis infection through medicalhistory or CT examination, or had a history of active pulmonary tuberculosisinfection within 1 year before enrollment, or had a history of active pulmonarytuberculosis infection more than 1 year ago without formal treatment;

11. There are factors that increase the risk of prolonged QTc and abnormal heart rate,such as heart failure, hypokalemia, congenital long QT syndrome, family history oflong QT syndrome, sudden unexplained death of immediate family members under 40years of age, or prolonged QT interval accompanied by medication;

12. Active hepatitis (Hepatitis B reference: HBsAg positive and HBV DNA≥2000 IU/ml;Hepatitis C reference: HCV antibody positive and HCV copy number > upper limit ofnormal);

13. Defined as ≥ grade 2 peripheral neuropathy according to NCI-CTCAE v5.0 standards;

14. Have been diagnosed with other malignancies within 5 years prior to initial dosing,unless malignancies with a low risk of metastasis or death (5-year survival > 90%),such as well-treated basal cell or squamous cell skin cancer of the skin or cervicalcarcinoma in situ may be considered for inclusion;

15. Known history of severe hypersensitivity to other monoclonal antibodies; Patientswith a known history of allergy or hypersensitivity to QL1706, oxaliplatin, andTigor or any of their components;

16. Known deficiency of dihydropyrimidine dehydrogenase;

17. Upper gastrointestinal obstruction or abnormal physiological function ormalabsorption syndrome that may affect the absorption of Tegor;

18. Pregnant or lactating women;

19. Enrolling in another clinical study at the same time, unless it is an observational,non-interventional clinical study or the follow-up period of an interventionalstudy;

20. The investigator determined that there were other factors that might have led to theforced termination of the study, such as other serious medical conditions (includingmental illness) requiring co-treatment, alcohol, substance abuse, family or socialfactors, and factors that might have affected the safety or adhere