A Single-Arm Study of QL1706 Combined With DOS as Neoadjuvant Therapy for Locally Advanced Gastric/GEJ Adenocarcinoma

Prior treatment

• Prior treatment with immune checkpoint inhibitors, including anti-PD-1, anti-PD-L1, and anti-CTLA-4 agents.
• Receipt of any antineoplastic agents within 4 weeks prior to the first dose of study drug.
• Any bleeding event ≥ CTCAE Grade 3 within 4 weeks prior to enrollment, or unhealed wounds, ulcers, or fractures.
• Concurrent enrollment in another clinical study, unless it is an observational (non-interventional) study or the follow-up phase of an interventional study.
• Subjects requiring systemic therapy with corticosteroids (\>10 mg/day prednisone or equivalent) or other immunosuppressive agents within 2 weeks prior to the first dose of study drug.
• Receipt of live or live-attenuated vaccine within 4 weeks prior to the first dose of study drug.
• Major surgery or significant trauma within 4 weeks prior to the first dose of study drug.
• Severe infection (CTCAE Grade \> 2) within 4 weeks prior to the first dose of study drug.
• Patients with a history of interstitial lung disease (except for radiation pneumonitis not treated with corticosteroids), non-infectious pneumonitis, or active pulmonary tuberculosis; or a history of active pulmonary tuberculosis within 1 year prior to enrollment, or more than 1 year prior to enrollment if not adequately treated.
• Other concomitant diseases that, in the opinion of the Investigator, pose a serious risk to the subject's safety or may interfere with the subject's ability to complete the study.

Other illness

• Known history of hypersensitivity or allergy to QL1706 or its excipients, tegafur/gimeracil/oteracil (S-1), oxaliplatin, docetaxel, or any of their excipients.
• History of another malignancy within 5 years prior to screening or concurrent malignancy, except for curatively treated carcinoma in situ of the cervix, non-melanoma skin cancer, and superficial bladder tumors.
• Patients with distant metastasis and/or unresectable disease;
• Patients with gastrointestinal disorders such as intestinal obstruction (including partial obstruction), or those with evidence or risk of gastrointestinal bleeding, perforation, or obstruction.
• Active or history of autoimmune disease, with the exception of vitiligo or resolved childhood asthma/atopy that requires no intervention in adulthood.
• History of immunodeficiency, including HIV infection, or other acquired or congenital immunodeficiency disorders, or history of organ transplantation or allogeneic bone marrow transplantation.
• Subjects with inadequately controlled cardiovascular clinical symptoms or diseases.

Other

• Pregnant or breastfeeding women.

• Aged 18 to 75 years; male or female.
• Previously untreated, resectable adenocarcinoma of the stomach or gastroesophageal junction (GEJ).
• Clinical stage cT3-4a/N+ M0.
• ECOG performance status 0-1.
• Adequate organ function within 7 days prior to treatment, meeting the following criteria: (1) Complete blood count (CBC) criteria (without blood transfusion within 14 days): Hemoglobin (Hb) ≥ 90 g/L; Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L; Platelet count (PLT) ≥ 80 × 10⁹/L; (2) Serum chemistry criteria: Total bilirubin (TBIL) ≤ 1.5 × upper limit of normal (ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN; Serum creatinine (Cr) ≤ 1.5 × ULN or creatinine clearance (CCr) ≥ 60 mL/min; (3) Doppler echocardiography: left ventricular ejection fraction (LVEF) ≥ lower limit of normal (50%). (4) Thyroid function: thyroid-stimulating hormone (TSH) ≤ upper limit of normal (ULN).
• Participants of childbearing potential must agree to use effective contraception during the study period and for 6 months after study completion.
• The participant voluntarily agrees to participate in this study and signs the informed consent form.