Envafolimab Combined With Chemotherapy in Metastatic or Recurrent Gastric Adenocarcinoma

Study Overview
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Brief Summary
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The objective is to investigate the efficacy and safety of Envafolimab combined with chemotherapy in the treatment of metastatic or recurrent gastric adenocarcinoma.

Detailed Description
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Envafolimab indication: Envafolimab is the world's first subcutaneous injection of PD-L1 monoclonal antibody.Suitable for adult patients with advanced solid tumors with unresectable or metastatic microsatellite highly unstable (MSI-H) or mismatch repair gene defects (dMMR).

Official Title
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A Prospective, Single-arm Clinical Trial of Envafolimab Combined With Chemotherapy in Metastatic or Recurrent Gastric Adenocarcinoma

Conditions
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Metastatic or Recurrent Gastric Adenocarcinoma

Intervention / Treatment
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* Drug: Envafolimab
* Drug: Oxaliplatin
* Drug: S1


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-75 years； ECOG 0-1； life expectancy of at least 3 months； Negative for HER2 gene expression by central laboratory ； The tumor expresses PD-L1 as detected by the central laboratory, and the tumor proportion score (CPS) ≥ 1； At least one measurable objective tumor lesion by spiral CT examination, the maximum diameter ≥ 1cm（according to RECIST 1.1）； Diagnosed by histology and/or cytology, and assessed by imaging (refer to RECIST 1.1) as advanced metastatic gastric adenocarcinoma or gastric adenocarcinoma that has recurred after previous gastric cancer surgery; Not received systemic chemotherapy in the past. Patients who have previously received fluorouracil monotherapy or fluorouracil-based adjuvant therapy or neoadjuvant therapy, and patients who have completed adjuvant therapy or neoadjuvant therapy before the start of the chemotherapy regimen in this trial 6 months ago can be included in this trial. In cases of metastatic disease requiring local remission, remission therapy with radiosensitizing doses of fluorouracil or capecitabine alone is permitted only ； satisfactory main organ function，laboratory test must meet the following criteria: hemoglobin (HGB) ≥90g/L, neutrophil count（ANC） ≥1.5×109/L, platelet count（PLT） ≥80×109/L, Serum creatinine（CR）≤1.5 upper normal limitation (UNL)，total bilirubin (TBil) ≤1.5 upper normal limitation (UNL), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 UNL (For patients with liver metastasis, the AST/ALT must be ≤5.0 UNL), Activated partial thromboplastin time (APTT), international normalized ratio (INR), prothrombin time (PT) ≤ 1.5×ULN; left ventricular ejection fraction (LVEF) ≥ 50%; thyroid stimulating hormone (TSH) within the normal range Within: if the baseline TSH exceeds the normal range, subjects with total T3 (or FT3) and FT4 within the normal range can also be enrolled; Subjects of childbearing potential must use an appropriate method of contraception during the study period and within 120 days after the end of the study, have a negative serum pregnancy test within 7 days prior to study enrollment, and must be non-lactating subjects ； Exclusion Criteria: Suffered from other malignant tumors within 5 years before the start of treatment in this study; Pathologically suggested patients with abnormally increased AFP OR MSI-H ； Grade ≥1 unresolved toxicities (according to the most recent version of the National Cancer Institute [NCI] Common Terminology Criteria for Adverse Events [CTCAE]) due to any prior therapy, excluding alopecia and fatigue; neurotoxicity was Recovery to ≤ grade 1 or baseline before the group; Subjects with any severe and/or uncontrolled disease ； Poorly controlled diabetes (fasting blood glucose [FBG] > 10 mmol/L) ； Received major surgical treatment, incisional biopsy, or significant traumatic injury within 28 days prior to the start of study treatment; or had a long-term unhealed wound or fracture； Serious arterial/venous thrombotic event within 6 months prior to initiation of study treatment ； Previously received drug therapy against PD-1, PD-L1 and other related immune checkpoints ； Participating in or participating in other clinical investigators within 4 weeks prior to the start of the study ； Allergic to the active ingredients or excipients of the study drug ； Unsuitable for the study or other chemotherapy determined by investigator.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: envafolimab plus chemotherapy<br>Envafolimab:300mg,sc,d1,Q3W; Chemotherapy:SOX(Oxaliplatin，130mg/m2, iv,d1,Q3W + S-1，40mg/m2, op,bid,d1-14,Q3W). | Drug: Envafolimab<br>* 300mg,sc,d1,Q3W<br>* Other names: Immunotherapy;Drug: Oxaliplatin<br>* 130mg/m2, iv,d1,Q3W<br>* Other names: Chemotherapy;Drug: S1<br>* 40mg/m2, op,bid,d1-14,Q3W<br>* Other names: Chemotherapy;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ORR | Objective response rate | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PFS | Progression Free Survival | 6 months | 
| OS | Overall Survival | 12 months | 
| DCR | Disease Control Rate | 9 months | 
| DOR | Duration of Response | 12 months | 
| AEs | Percentage of participants experiencing grade 3-5 adverse events | 12 months | 
| Qualify of Life | Based on Quality of Life Questionnare-Core 30, evaluate the quality of life of patients | 12 months |