A Phase II, Multicenter, Randomized, Controlled Clinical Study Comparing the Efficacy and Safety of Sintilimab Plus SOX Versus SOX Alone as Adjuvant Therapy for PD-L1-Positive, Stage pN3 Gastric Cancer

NCT07263386 | Recruiting Phase 2 DMC

• 1 other identifier: 2025-SR-859
• Study Type: interventional
• Target: 460
• Locations: 1 country
• Sites: 1

Brief Summary

This study intends to enroll gastric cancer patients who are PD-L1 positive and pathologically confirmed as Stage N3. Enrolled patients will be randomly assigned to receive either standard adjuvant SOX regimen or SOX regimen combined with sintilimab. The objective of the study is to determine whether adding a PD-1 inhibitor to postoperative chemotherapy can improve the Disease-Free Survival (DFS) rate in patients with Stage N3 gastric cancer.

Conditions

Gastric Adenocarcinoma

Keywords

PD-1 inhibitor; adjuvant therapy; Sintilimab; Gastric Adenocarcinoma

Outcome Measures

Primary Outcomes (1)

• Disease-Free Survival (DFS)

  Defined from the date of completion of curative-intent treatment (e.g., surgery, adjuvant chemotherapy) to the date of first documentation of disease recurrence (e.g., tumor relapse, metastasis) or death from any cause, whichever occurs first.

  3 years

Secondary Outcomes (3)

• Overall Survival (OS)

  5 years

• Incidence rate of adverse events (AEs)

  3 years

• Serious adverse events (SAE)

  3 years

Study Arms (2)

Sintilimab + SOX

ACTIVE COMPARATOR

Patients will first receive 6 to 8 cycles of treatment with sintilimab + SOX; sintilimab will subsequently be continued as maintenance therapy for up to one year.

Drug: Sintilimab; Drug: SOX Chemotherapy

SOX

ACTIVE COMPARATOR

Patients will receive 6 to 8 cycles of treatment with SOX

Drug: SOX Chemotherapy

Interventions

Sintilimab DRUG

For patients with body weight \< 60 kg, the dose is 3 mg/kg, administered via intravenous infusion (i.v.gtt.) on Day 1; for patients with body weight ≥ 60 kg, a fixed dose of 200 mg is administered via intravenous infusion (i.v.gtt.) on Day 1. The treatment is repeated every 21 days.

Sintilimab + SOX

SOX Chemotherapy DRUG

S-1: 40 mg/m², oral administration (p.o.), twice daily (b.i.d.), on Days 1 to 14; repeated every 21 days. Oxaliplatin: 130 mg/m², intravenous infusion (i.v.gtt.), on Day 1; repeated every 21 days.

SOX; Sintilimab + SOX

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Sign a written informed consent form prior to the initiation of any study-related procedures.
• Aged between 18 and 75 years.
• Have undergone radical resection with D2 or wider lymph node dissection and achieved R0 resection status.
• No prior systemic anti-tumor treatment (i.e., neoadjuvant therapy) before surgery.
• Histopathologically confirmed gastric adenocarcinoma.
• Pathological stage classified as TxN3M0 according to the 8th edition of the AJCC Cancer Staging Manual.
• PD-L1 Combined Positive Score (CPS) ≥ 1.
• Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or 1.
• Expected survival time ≥ 6 months.
• Adequate organ function, with subjects meeting the following laboratory criteria before enrollment:
• Absolute Neutrophil Count (ANC) ≥ 1.5×10⁹/L without the use of granulocyte colony-stimulating factor (G-CSF) within the past 14 days.
• Platelet count ≥ 100×10⁹/L without blood transfusion within the past 14 days. Hemoglobin \> 9 g/dL without blood transfusion or use of erythropoietin within the past 14 days.
• Total bilirubin ≤ 1.5×Upper Limit of Normal (ULN); subjects with total bilirubin \> 1.5×ULN but direct bilirubin ≤ ULN are also eligible.
• Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) ≤ 2.5×ULN. Serum creatinine ≤ 1.5×ULN and creatinine clearance (calculated using the Cockcroft-Gault formula) ≥ 60 mL/min.
• Adequate coagulation function, defined as International Normalized Ratio (INR) or Prothrombin Time (PT) ≤ 1.5×ULN.

You may not qualify if:

• Pathologically confirmed as squamous cell carcinoma, adenosquamous carcinoma, undifferentiated carcinoma, neuroendocrine tumor, or gastrointestinal stromal tumor (mixed carcinoma with adenocarcinoma component \> 80% is eligible for enrollment).
• Diagnosis of malignant diseases other than gastric cancer within 5 years before the first dose administration (excluding radically treated basal cell carcinoma of the skin, cutaneous squamous cell carcinoma, differentiated thyroid cancer, and/or radically resected carcinoma in situ).
• Currently participating in therapeutic clinical research, or having received other study drugs within 4 weeks before the first dose administration.
• Previous receipt of the following therapies: anti-PD-1, anti-PD-L1, or drugs targeting other stimulatory or co-inhibitory T-cell receptors (including but not limited to CTLA-4, OX-40, CD137, etc.).
• Receipt of Chinese patent medicines with anti-tumor indications or drugs with immunomodulatory effects (including thymosin, interferon, interleukin, except for local use to control pleural effusion) via systemic treatment within 2 weeks before the first dose administration.
• History of active autoimmune diseases requiring systemic treatment (e.g., disease-modifying drugs, glucocorticoids, or immunosuppressants) within 2 years before the first dose administration. Replacement therapies (e.g., thyroxine, insulin, or physiological glucocorticoids for adrenal or pituitary insufficiency) are not considered systemic treatment.
• Receipt of systemic glucocorticoid therapy (excluding nasal, inhaled, or other forms of topical glucocorticoids) or any other form of immunosuppressive therapy within 7 days before the first dose administration of the study; Note: - - Use of physiological doses of glucocorticoids (≤ 10 mg/day prednisone or equivalent drugs) is allowed.
• Known history of allogeneic organ transplantation (except corneal transplantation) or allogeneic hematopoietic stem cell transplantation.
• Known history of allergy to drugs used in this study.
• Failure to fully recover from toxicity and/or complications caused by any intervention before the start of treatment (i.e., ≤ Grade 1 or return to baseline, excluding fatigue or alopecia).
• Known history of human immunodeficiency virus (HIV) infection (i.e., positive HIV 1/2 antibodies).
• Untreated active hepatitis B (defined as positive HBsAg with HBV-DNA copy number exceeding the upper limit of normal value of the laboratory in the research center); Note: Hepatitis B subjects meeting the following criteria are also eligible: HBV viral load \< 1000 copies/ml (200 IU/ml) before the first dose administration, and subjects should receive anti-HBV treatment during the entire study chemotherapy period to avoid viral reactivation. For subjects with anti-HBc (+), HBsAg (-), anti-HBs (-), and negative HBV viral load, prophylactic anti-HBV treatment is not required, but close monitoring of viral reactivation is necessary.
• Subjects with active HCV infection (positive HCV antibody and HCV-RNA level above the lower limit of detection).
• Receipt of live vaccines within 30 days before the first dose administration (Cycle 1, Day 1); Note: Receipt of inactivated influenza vaccines via injection within 30 days before the first dose administration is allowed, but intranasal attenuated live influenza vaccines are not allowed.
• Pregnant or lactating women.

Sponsors & Collaborators

• The First Affiliated Hospital with Nanjing Medical University: lead

Study Sites (1)

The First Affiliated Hospital with Nanjing Medical University

Nanjing, Jiangsu, 210029, China

RECRUITING

MeSH Terms

Interventions

sintilimab

Central Study Contacts

Hao Xu, M.D & Ph.D

CONTACT

025-68306505; Hxu@njmu.edu.cn

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 24, 2025
• First Posted: December 4, 2025
• Study Start: October 23, 2025
• Primary Completion (Estimated): October 1, 2028
• Study Completion (Estimated): October 1, 2030
• Last Updated: December 4, 2025

Record last verified: 2025-10

Locations

CN (1)