LM-302 and S-1 Plus Intraperitoneal Paclitaxel With or Without Cadonilimab for Claudin 18.2-positive Gastric or Gastroesophageal Junction Adenocarcinoma With Peritoneal Metastasis: a Prospective, Exploratory Study

LM-302 and S-1 Plus Intraperitoneal Paclitaxel With or Without Cadonilimab for Claudin 18.2-positive Gastric Cancer With Peritoneal Metastasis: a Prospective, Exploratory Study

In this study, the investigators will use LM-302 and S-1 plus intraperitoneal paclitaxel with or without Cadonilimab to treat Claudin 18.2-positive gastric or gastroesophageal junction adenocarcinoma with peritoneal metastasis.

Study Overview

• Status: Recruiting
• Conditions: Gastric Cancer Stage IV; Peritoneal Metastases From Gastric Cancer; Gastric or Esophagogastric Junction Adenocarcinoma
• Intervention / Treatment: Drug: LM-302, S-1, paclitaxel; Drug: LM-302, Cadonilimab, S-1, paclitaxel

• Study Type: Interventional
• Enrollment (Estimated): 74
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Zhongyin Yang; Phone Number: 8621-64370045; Email: jeffreyyong@163.com

Study Locations

• China
  • Huangpu District
    • Shanghai, Huangpu District, China, 200025
      • Recruiting
      • Ruijin Hospital Shanghai Jiao Tong University School of Medicine
      • Contact: Phone Number: 13564877661; Email: zyyang@shsmu.edu.cn

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Histologically confirmed gastric or gastroesophageal junction adenocarcinoma with her 2 (-), and without the history of resection of primary or metastatic lesion;
• Age ≥ 18 years at registration;
• Peritoneal metastases from gastric cancer requiring definitive diagnosisby laparoscopy, and without gastric outflow tract obstruction andintestinal obstruction;
• Claudin 18.2 positive (≥ 25%, moderate to strong staining);
• Eastern Cooperative Oncology Group (ECOG) score ≤ 1;
• Expected life expectancy > 3 months;
• Adequate bone marrow, liver, and renal functions.

Exclusion Criteria:

• Presence of distant metastases other than peritoneal metastasis at the time of enrollment;
• Pregnant or breastfeeding women;
• Prior treatment with Claudin 18.2 targeted therapy;
• History of other malignancies within the past 5 years, except for cured skin cancer or cervical carcinoma in situ;
• History of uncontrolled epilepsy, central nervous system disease, or mental disorder that, in the investigator's judgment, may interfere with signing informed consent or compliance with oral medication.
• Clinically significant active heart disease, such as symptomatic coronary artery disease, New York Heart Association (NYHA) class II or higher congestive heart failure, severe arrhythmia requiring medication, or myocardial infarction within the past 12 months;
• Upper gastrointestinal obstruction, abnormal physiological function, or malabsorption syndrome that may affect S 1 absorption;
• Known peripheral neuropathy ≥ NCI CTC AE grade 1. However, patients with loss of deep tendon reflexes (DTR) alone may be included;
• Organ transplantation requiring immunosuppressive therapy;
• Severe uncontrolled recurrent infection or other severe uncontrolled concomitant diseases;
• Moderate or severe renal impairment (creatinine clearance ≤ 50 ml/min) or serum creatinine above the upper limit of normal;
• Known dihydropyrimidine dehydrogenase (DPD) deficiency;
• Active hepatitis (for hepatitis B: HBsAg positive and HBV DNA ≥ 500 IU/ml; for hepatitis C: HCV antibody positive and HCV viral load > upper limit of normal);
• Psychiatric disorder that makes the patient unable to comply with treatment;
• Allergy to paclitaxel or any component of the study drugs;
• History or evidence of any disease, condition, treatment, or laboratory abnormality that could interfere with the study results or the patient's full participation, or any other condition that, in the investigator's opinion, makes the patient unsuitable for enrollment.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LM-302 and S-1 Plus Intraperitoneal Paclitaxel	Drug: LM-302, S-1, paclitaxel; LM-302 2.0mg/kg intravenous (IV) infusion on day 1, paclitaxel 20 mg/m2 intraperitoneal infusion on Days 1 and 8 plus oral S-1: BSA<1.25 m2, 40mg twice/day; BSA1.25-1.5m2, 50mg twice/day; BSA≥1.5 m2, 60mg twice/day, po, d1-14, q3w.
Active Comparator: LM-302 and S-1 Plus Intraperitoneal Paclitaxel combined with Cadonilimab	Drug: LM-302, Cadonilimab, S-1, paclitaxel; LM-302 2.0 mg/kg, Cadonilimab 10mg/kg intravenous (IV) infusion on day 1, paclitaxel 20 mg/m2 intraperitoneal infusion on Days 1 and 8 plus oral S-1: BSA<1.25 m2, 40mg twice/day; BSA1.25-1.5m2, 50mg twice/day; BSA≥1.5 m2, 60mg twice/day, po, d1-14, q3w.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
1-year survival rate	up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall survival (OS)		up to 36 months
treatment related adverse events		up to 24 months
Progressive free survival (PFS)	Progression-free survival (PFS) is defined as the time from enrollemnt to disease progression or death from any cause.	up to 36 months
Disease control rate (DCR)		up to 24 months
Objective response rate (ORR)	ORR is defined as the proportion of subjects in the analysis population who achieve confirmed objective response (CR or PR) as assessed by the IRRC per RECIST v1.1 criteria.	up to 24 months
Major Pathological Response (MPR) rate	Defined as tumor specimens resected after conversion surgery with residual tumor cells ≤10%	up to 24 months

Collaborators and Investigators

• Sponsor: Ruijin Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 17, 2026
• Primary Completion (Estimated): April 30, 2028
• Study Completion (Estimated): April 30, 2029

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: April 24, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 24, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Gastric cancer; Paclitaxel; Peritoneal metastasis; Claudin 18.2; Cadonilimab; Gastric or Esophagogastric Junction Adenocarcinoma
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Stomach Diseases; Stomach Neoplasms; Organic Chemicals; Hydrocarbons; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Taxoids; Cyclodecanes; Diterpenes; Paclitaxel; S 1 (combination)
• Other Study ID Numbers: DRAGON-17

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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