QL1706-SOX vs SOX Alone as Neoadjuvant Therapy for Resectable Diffuse-Type Gastric Cancer

A Randomized, Controlled, Phase-II Trial of Neoadjuvant QL1706 (Iparomlimab /Tuvonralimab) Combined With SOX Versus SOX Alone Followed by Curative Gastrectomy in Patients With Locally Advanced Diffuse-Type Gastric Adenocarcinoma

The goal of this randomized, open-label, phase II clinical trial is to determine whether adding the PD-1/CTLA-4 bispecific antibody QL1706 to standard SOX chemotherapy increases the pathological complete response rate in adults aged 18-75 years with resectable, locally advanced, diffuse-type, HER2-negative gastric adenocarcinoma (cT3-4aNxM0). Participants will be randomly assigned (1:1) to receive 3-4 neoadjuvant cycles of QL1706 plus SOX or SOX alone every 3 weeks, followed by curative-intent gastrectomy with D2 lymphadenectomy, and will be monitored post-operatively every 3 months for 2 years and every 6 months thereafter for recurrence, survival, and safety.

Study Overview

Status

Not yet recruiting

Study Type

Interventional

Enrollment (Estimated)

74

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Jiangsu
      • Nanjing, Jiangsu, China, 210029
        • First Affiliated Hospital with Nanjing Medical University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Histologically confirmed diffuse-type gastric adenocarcinoma (Lauren classification) with signet-ring cells ≥ 50 % of tumor volume HER2-negative by IHC or ISH per ASCO/CAP guidelines Clinical stage cT3-4aNxM0 (AJCC 8th ed.) on baseline EUS + contrast-enhanced CT/MRI; disease judged resectable by multidisciplinary team No prior gastric surgery, chemotherapy, radiotherapy, or immunotherapy for cancer Age 18-75 years; ECOG performance status 0-1 Adequate organ function (ANC ≥ 1.5 × 10⁹/L, platelet ≥ 100 × 10⁹/L, Hb ≥ 9 g/dL, ALT/AST ≤ 2.5 × ULN, TBIL ≤ 1.5 × ULN, creatinine ≤ 1.5 × ULN and calculated CrCl ≥ 60 mL/min, INR/PT ≤ 1.5 × ULN) within 14 days before randomization Left-ventricular ejection fraction ≥ 50 % by echocardiography; no clinically significant ECG abnormalities Negative serum β-hCG pregnancy test ≤ 7 days of first dose for women of child-bearing potential; agreement to use effective contraception through 6 months post-surgery Life expectancy ≥ 6 months Signed informed consent; able to comply with study procedures and follow-up

Exclusion Criteria:

Mixed or intestinal Lauren histology; mucinous or hepatoid variants Active gastrointestinal bleeding or endoscopic evidence of major vessel invasion Other malignancy within 5 years (except curatively treated basal-cell carcinoma, cervical carcinoma in situ, or superficial bladder cancer) Prior exposure to any anti-PD-1, anti-PD-L1, anti-CTLA-4, or other T-cell co-stimulatory/antagonist agents Autoimmune disease requiring systemic immunosuppression within 2 years (e.g., prednisone > 10 mg/day equivalent) Receipt of live vaccine ≤ 30 days before first dose Known HIV-positive, active hepatitis B (HBsAg+ and HBV-DNA > 200 IU/mL), or hepatitis C infection (HCV RNA positive) Active tuberculosis or history of incompletely treated TB Severe cardiovascular disease: NYHA class ≥ II heart failure, unstable angina, myocardial infarction ≤ 6 months, uncontrolled arrhythmia, or uncontrolled hypertension (systolic > 160 mmHg or diastolic > 100 mmHg) Peripheral neuropathy ≥ grade 2 per NCI-CTCAE v5.0 Pulmonary disease requiring systemic steroids (e.g., ≥ grade 2 pneumonitis) or oxygen therapy Active infection requiring systemic antibiotics, antivirals, or antifungals ≤ 7 days before first dose Known hypersensitivity to oxaliplatin, fluoropyrimidines, or Chinese hamster ovary cell-derived products Pregnancy or lactation Concurrent participation in another interventional clinical trial Any condition that, in the investigator's opinion, would compromise safe completion of protocol therapy or accurate assessment of outcomes

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: QL1706+SOX
QL1706 (Iparomlimab/Tuvonralimab) 5 mg/kg intravenous infusion on day 1 plus SOX (S-1 40-60 mg orally twice daily days 1-14 and oxaliplatin 130 mg/m² intravenous infusion on day 1) every 3 weeks for 3-4 cycles before curative gastrectomy.
QL1706 is a first-in-class, fixed-ratio bispecific monoclonal antibody produced in a single Chinese hamster ovary cell line that simultaneously targets PD-1 (IgG4 framework) and CTLA-4 (IgG1 framework) with an approximate 2:1 molar ratio. This molecular design delivers dual immune checkpoint blockade in one infusion, distinguishing it from separate-agent combinations such as nivolumab plus ipilimumab. In this study QL1706 is given at 5 mg/kg (actual body weight) as a 60-minute intravenous infusion on day 1 of each 21-day cycle, immediately followed by oxaliplatin 130 mg/m² (2-hour infusion) and oral S-1 (40-60 mg bid days 1-14). The sequence is repeated for 3-4 cycles before planned surgery; no intra-patient dose escalation or reduction is allowed, but infusion may be delayed ≤12 weeks for immune-related adverse events. The comparator arm receives identical SOX chemotherapy without any investigational antibody, ensuring that any difference in pathological outcome can be attributed spec
SOX chemotherapy consists of oxaliplatin 130 mg/m² delivered as a 2-hour intravenous infusion on day 1 plus oral S-1 (tegafur 40-60 mg, gimeracil and oteracil potassium in fixed 1:0.4:1 molar ratio) taken twice daily on days 1-14 of a 21-day cycle, repeated for 3-4 cycles before curative-intent gastrectomy. The S-1 dose is calculated by body-surface area: <1.25 m² → 40 mg, 1.25-1.5 m² → 50 mg, >1.5 m² → 60 mg per administration.
Active Comparator: SOX
S-1 40-60 mg orally twice daily days 1-14 and oxaliplatin 130 mg/m² intravenous infusion on day 1 every 3 weeks for 3-4 cycles before curative-intent gastrectomy.
SOX chemotherapy consists of oxaliplatin 130 mg/m² delivered as a 2-hour intravenous infusion on day 1 plus oral S-1 (tegafur 40-60 mg, gimeracil and oteracil potassium in fixed 1:0.4:1 molar ratio) taken twice daily on days 1-14 of a 21-day cycle, repeated for 3-4 cycles before curative-intent gastrectomy. The S-1 dose is calculated by body-surface area: <1.25 m² → 40 mg, 1.25-1.5 m² → 50 mg, >1.5 m² → 60 mg per administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pathological complete response (pCR) rate
Time Frame: Perioperative
Pathological complete response (pCR) rate, defined as the proportion of participants who achieve ypT0N0 (absence of viable tumor cells in the resected primary tumor and all examined lymph nodes, Mandard TRG 1 or Becker grade 1) after completion of 3-4 cycles of protocol-specified neoadjuvant therapy and subsequent curative-intent gastrectomy, assessed by central review of H&E-stained slides according to AJCC 8th edition criteria within 4 weeks of surgery.
Perioperative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

January 1, 2026

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2030

Study Registration Dates

First Submitted

December 5, 2025

First Submitted That Met QC Criteria

December 18, 2025

First Posted (Estimated)

January 2, 2026

Study Record Updates

Last Update Posted (Estimated)

January 2, 2026

Last Update Submitted That Met QC Criteria

December 18, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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