Perioprative Study of IBI363 in Patients With MHC-II-Negative Locally Advanced Gastric Cancer

IBI363 Combined Chemotherapy for Perioperative Treatment of MHC-II-Negative Locally Advanced Gastric/Gastroesophageal Junction Adenocarcinoma: A Single-Center, Single-Arm Phase II Clinical Study

This is a phase 2 study designed to evaluate the safety and efficacy of IBI363 in combination with oxaliplatin and capecitabine (XELOX) or S-1 and oxaliplatin (SOX) in perioprative treatment of locally advanced MHC-II-negative gastric and gastroesophageal junction adenocarcinoma.

Study Overview

• Status: Recruiting
• Conditions: IBI363 + Chemotherapy
• Intervention / Treatment: Drug: IBI363 + chemotherapy

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Xiangdong Cheng; Phone Number: 13968032995; Email: chengxd516@126.com

Study Locations

• China
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310022
      • Recruiting
      • Zhejiang Cancer Hospital
      • Contact: Xiangdong Cheng

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

1. Patients voluntarily enrolled in this study and signed informed consent forms;
2. Age 18-75 years;
3. Pathologically confirmed gastric adenocarcinoma or gastroesophageal junction adenocarcinoma;
4. MHC-II negative, with <5% tumour cells displaying staining <2+ (grade 2 or stronger);
5. Clinically staged as cT3-4aN+M0 gastric or gastroesophageal junction adenocarcinoma confirmed by CT and/or laparoscopy (per AJCC 8th Edition staging);
6. No prior antineoplastic therapy for current disease (e.g., surgery, radiotherapy, chemotherapy, targeted therapy, immunotherapy);
7. Scheduled for surgical intervention following completion of neoadjuvant therapy;
8. Able to swallow tablets orally;
9. ECOG performance status 0-1;
10. Expected survival ≥6 months.

Key Exclusion Criteria:

1. Pregnant or lactating women, or women planning to become pregnant within 6 months prior to, during, or after the last dose of the investigational medicinal product.
2. Known signs of active bleeding from a lesion.
3. Patients with known dMMR/MSI-H status.
4. Oesophageal or pyloric near-obstruction affecting the subject's ability to eat or gastric emptying, or difficulty swallowing tablets.
5. Subjects with unresolved Grade >1 toxicity related to any prior antineoplastic therapy (excluding persistent Grade 2 alopecia, anaemia, peripheral neuropathy, electrolyte abnormalities correctable with treatment, or endocrine abnormalities controlled and stable with hormone replacement therapy).
6. Known dihydropyrimidine dehydrogenase (DPD) deficiency (or prior fluorouracil-containing therapy resulting in Grade 3 or higher mucositis).
7. Known hypersensitivity to any monoclonal antibody or component of the chemotherapy agents (capecitabine, oxaliplatin) (resulting in Grade 3 or higher hypersensitivity reaction).
8. History of epileptic seizures, active, newly diagnosed, or untreated central nervous system metastases, spinal cord compression, carcinomatous meningitis, or leptomeningeal metastases.
9. Clinically significant cardiovascular or cerebrovascular disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Arm; IBI363 combination with oxaliplatin and capecitabine (XELOX) or S-1 and oxaliplatin (SOX) for perioprative treatment of locally advanced gastric and gastroesophageal junction adenocarcinoma	Drug: IBI363 + chemotherapy; IBI363 Q3W +XELOX Q3W (Oxaliplatin 130 mg/m2, IV, Q3W, Capecitabine ,1000mg/ m2, PO, Bid, d1-14, Q3W) or IBI363 Q3W +SOX (Oxaliplatin 130 mg/m2, IV, Q3W, S-1, 40-60mg,PO, Bid, d1-14，Q3W )

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pathological Complete Response (pCR) rate of ITT population	The proportion of subjects in the cohort defined as having no residual tumour cells detected microscopically and lymph node-negative following neoadjuvant therapy.	Up to 3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pathological Complete Response (pCR) Rate or surgical population	The proportion of subjects undergoingvradical surgery who, following neoadjuvant therapy, were found to have no residual tumour cells under microscopic examination and negative lymph nodes.	Up to 3 years
Major Pathologic Response (MPR) Rate of ITT Population	The proportion of subjects in the enrolled population who achieved pathological residual tumour ≤10% as defined by tumour regression induced by neoadjuvant therapy.	Up to 3 years
Major Pathologic Response (MPR) Rate of surgical population	The proportion of subjects undergoing radical surgery who achieved pathological residual tumour ≤10% following neoadjuvant therapy-induced tumour regression.	Up to 3 years
R0 Resection Rate	The proportion of subjects defined as having undergone R0 resection within the radical resection population.	Up to 3 years
Event-free Survival (EFS)	Defined as the time from randomization to the first occurrence of disease progression determined using RECIST v1.1, inoperable disease, local recurrence following surgery, distant metastasis, or death from any cause, whichever occurs first.	Up to 3 years
Overall Survival (OS)	Defined as the time from randomization to death from any cause.	Up to 3 years
AE	Number of participants experiencing clinical adverse events (AEs)	Up to 90 days post last dose

Collaborators and Investigators

• Sponsor: Zhejiang Cancer Hospital

Study record dates

Study Major Dates

• Study Start (Actual): November 3, 2025
• Primary Completion (Estimated): May 30, 2026
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: December 24, 2025
• First Submitted That Met QC Criteria: December 24, 2025
• First Posted (Actual): January 8, 2026

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: December 24, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Therapeutics; Drug Therapy
• Other Study ID Numbers: CIBI363Y122

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No