Retlirafusp Alfa Injection Combined Chemotherapy for Perioperative Treatment of Esophagogastric Junction Adenocarcinoma: A Single-Arm, Phase II Study of Safety and Efficacy

This is a prospective, phase II, exploratory clinical trial. The study aims to evaluate the efficacy and safety of Retlirafusp alfa Injection in combination with chemotherapy during the perioperative period for the treatment of adenocarcinoma of the gastroesophageal junction.

A perioperative regimen comprising 3 cycles of neoadjuvant therapy → surgery → postoperative stratified maintenance therapy was employed, specifically: Retlirafusp alfa Injection (30 mg/kg, intravenous injection, D1) combined with capecitabine (1000 mg/m², oral, twice daily, D1-14) + oxaliplatin (130 mg/m², IV, D1) every 3 weeks for 3 cycles, followed by surgery; Postoperatively stratified by Tumor Regression Grade (TRG): TRG 2-4 patients receive Retlirafusp alfa Injection maintenance therapy until disease progression or intolerance (maximum duration not exceeding 1 year); TRG 1/5 patients undergo postoperative observation only.

Study Overview

• Status: Not yet recruiting
• Conditions: GEJ Adenocarcinoma
• Intervention / Treatment: Drug: Retlirafusp alfa Injection

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Chuangui chen Tianjin Medical University Cancer Institute & Ho; Phone Number: 18622228653; Email: ccg209@163.com

Participation Criteria

Eligibility Criteria

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

Description

**Inclusion Criteria:**

• Patients voluntarily enrolled in this study and signed informed consent forms;
• Aged 18-75 years, no gender restrictions;
• Histopathologically confirmed adenocarcinoma of the gastroesophageal junction with CPS > 5 and HER2-negative status;
• Clinical stage T3-4aNxM0 gastroesophageal junction adenocarcinoma (AJCC/UICC 8th Edition cTNM staging for esophageal/esophagogastric junction cancer); 5. Clinically determined resectable Siewert Type I or Siewert Type II locally advanced gastroesophageal junction adenocarcinoma;
• At least one measurable lesion present, with spiraled CT scan feasible for efficacy assessment;
• No prior anticancer therapy;
• ECOG performance status: 0-1;

• Adequate major organ function meeting the following criteria (no blood components or cell growth factors administered within 14 days prior to randomization):

  1. Neutrophils ≥ 1.5 × 10⁹/L; platelets ≥ 80 × 10⁹/L; hemoglobin ≥ 9 g/dL; serum albumin ≥ 3 g/dL;
  2. Total bilirubin ≤ 1.5 times upper limit of normal (biliary drainage permitted for biliary obstruction); ALT and AST ≤ 3 times upper limit of normal;
  3. Serum creatinine ≤ 1.5 times the upper limit of normal, creatinine clearance ≥ 50 mL/min;
  4. INR ≤ 1.5 times the upper limit of normal and APTT ≤ 1.5 times the upper limit of normal (patients on stable anticoagulant therapy such as low molecular weight heparin or warfarin with INR within the therapeutic range may be included in screening); (5) Electrocardiogram: QTcF ≤ 450 milliseconds (males), ≤ 470 milliseconds (females);

  (6) Cardiac ultrasound: Left ventricular ejection fraction (LVEF) ≥ 60%;

• For patients with active hepatitis B virus (HBV) infection: HBV DNA must be <500 IU/mL (if the study site only has copy/mL units, then <2500 copies/mL), and must have received at least 14 days of anti-HBV therapy (based on local standard treatment, e.g., entecavir) prior to study treatment initiation, with willingness to continue antiviral therapy throughout the study period; Patients with hepatitis C virus (HCV) RNA positivity must receive antiviral therapy according to local standard treatment guidelines, with liver function within the range of CTCAE Grade 1 elevation;
• Women of childbearing potential must have a negative blood pregnancy test within 3 days prior to randomization and agree to use effective contraception during the trial and for 6 months after treatment completion. Men must be surgically sterilized or agree to use effective contraception during the study and for 3 months after treatment completion.

**Exclusion Criteria:**

• Pregnant or lactating patients;
• Patients who have received prior antitumor therapy, including chemotherapy, radiotherapy, targeted therapy, or immunotherapy;
• Patients with other malignancies within the past 5 years (excluding basal cell carcinoma, superficial bladder cancer, cervical carcinoma in situ, or breast cancer);
• Uncontrolled pleural effusion, pericardial effusion, or ascites;
• Clinically determined to be inoperable or with distant metastasis;
• Severe cardiovascular disease within 12 months prior to enrollment, such as symptomatic coronary artery disease, congestive heart failure ≥ Grade II, uncontrolled arrhythmia, myocardial infarction;
• Concurrent upper gastrointestinal obstruction/bleeding, digestive dysfunction, or malabsorption syndrome;
• History of gastrointestinal perforation within 6 months prior to enrollment;
• Concurrent severe uncontrolled infections or other severe uncontrolled comorbidities, moderate or severe renal impairment;

• Uncontrolled cardiac clinical symptoms or conditions, such as:

  1. NYHA Class II or higher heart failure (see Appendix 5) or echocardiography showing LVEF <50%;
  2. Unstable angina;
  3. Myocardial infarction within 1 year prior to study treatment initiation;
  4. Clinically significant supraventricular or ventricular arrhythmias requiring treatment or intervention; (5) QTc > 450 ms (males); QTc > 470 ms (females) (QTc interval calculated using Fridericia's formula; if QTc is abnormal, measure three consecutive times at 2-minute intervals and take the average);
• History of allergic reactions to drugs used in this study;
• Use of immunosuppressive drugs within 4 weeks prior to the first dose of study treatment, excluding intranasal, inhaled, or other locally administered corticosteroids, or physiologically dosed systemic corticosteroids (i.e., not exceeding 10 mg/day of prednisone or equivalent doses of other corticosteroids), or corticosteroids used for contrast medium allergy prophylaxis;
• Known history of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation;
• Current interstitial pneumonia or interstitial lung disease, or prior history of interstitial pneumonia or interstitial lung disease requiring corticosteroid therapy, or other pulmonary conditions that may interfere with the assessment and management of immune-related pulmonary toxicity, such as pulmonary fibrosis, organizing pneumonia (e.g., obliterative bronchiolitis), pneumoconiosis, drug-induced pneumonia, idiopathic pneumonia, or evidence of active pneumonia on screening chest computed tomography (CT) or severe pulmonary impairment. Radiation pneumonitis in the radiation field is permitted. Active tuberculosis.
• Active autoimmune disease or history of autoimmune disease with potential for recurrence (including but not limited to: autoimmune hepatitis, interstitial pneumonia, uveitis, enteritis, hypophysitis, vasculitis, nephritis, hyperthyroidism, hypothyroidism [subjects controllable only with hormone replacement therapy may be included]); Subjects with skin conditions not requiring systemic treatment (e.g., vitiligo, psoriasis, alopecia), controlled type 1 diabetes managed with insulin, or childhood asthma in complete remission requiring no adult intervention may be included; asthma patients requiring bronchodilator medical intervention are excluded;
• Use of immunosuppressive agents or systemic corticosteroids for immunosuppression within 14 days prior to study treatment initiation (dose > 10 mg/day prednisone or equivalent);
• Severe infection within 4 weeks prior to study treatment initiation, including but not limited to hospitalization due to infection, bacteremia, or severe pneumonia complications; therapeutic antibiotic administration (oral or intravenous) within 2 weeks prior to study treatment initiation (patients receiving prophylactic antibiotics, e.g., for urinary tract infection prevention or chronic obstructive pulmonary disease exacerbation prevention, are eligible);
• Patients with congenital or acquired immunodeficiency (e.g., HIV infection);
• Use of immunosuppressive drugs within 4 weeks prior to first dose;
• Administration of live attenuated vaccines within 4 weeks prior to first dose or planned administration of live attenuated vaccines during the study period;
• Previous treatment with other anti-PD-1 antibodies or other PD-1/PD-L1-targeted immunotherapies;
• Palliative radiotherapy to non-target lesions for symptom control is permitted, provided it was completed at least 2 weeks prior to study treatment initiation and radiotherapy-related adverse events have not recovered to ≤CTCAE Grade 1;
• Receipt of other investigational drug treatment within 28 days prior to study treatment initiation; The investigator determined that the patient has other factors that may affect study outcomes or necessitate premature termination of this study, such as alcohol abuse, substance misuse, other serious medical conditions (including psychiatric disorders) requiring concomitant treatment, severe laboratory abnormalities, or accompanying family or social factors that could compromise patient safety.

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: Retlirafusp alfa Injection+ Capecitabine + Oxaliplatin

Drug: Retlirafusp alfa Injection; Retlirafusp alfa Injection (30 mg/kg, intravenous injection, D1) + capecitabine (1000 mg/m², oral, twice daily, D1-14) + oxaliplatin (130 mg/m², intravenous injection, D1) administered every 3 weeks for 3 cycles, followed by surgical intervention; Postoperatively stratified by Tumor Regression Grade (TRG): TRG 2-4 patients receive Retlirafusp alfa Injection maintenance therapy until disease progression or intolerance (maximum duration not exceeding 1 year); TRG 1/5 patients undergo postoperative observation only.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
pathological complete response (pCR) rate;	through study completion, an average of 1 year.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
R0 Resection Rate	Assess the proportion of patients achieving R0 resection (no residual tumor at the surgical margin) within 4 weeks after surgery (surgery performed 6-12 weeks after 3 cycles of neoadjuvant therapy)	18 to 24 weeks after the first dose
Tumor Regression Grade (TRG)	Pathological evaluation of tumor regression grade of surgical resected specimens by the pathology department within 4 weeks after surgery	18 to 24 weeks after the first dose
Major Pathological Response (MPR)	Pathological assessment of major pathological response (≤10% residual viable tumor) of surgical resected specimens within 4 weeks after surgery, synchronized with TRG evaluation	18 to 24 weeks after the first dose
Objective Response Rate (ORR)	Radiological evaluation of ORR by spiral CT according to RECIST v1.1 at the end of neoadjuvant therapy;; Recheck before surgery, with the pre-surgery result as the final ORR of the neoadjuvant stage	1. 9 weeks after the first dose (1 week after the end of 3 cycles of neoadjuvant therapy); 2. 18 to 24 weeks after the first dose (before surgery)
Duration of Response (DoR)	From the first documentation of objective response (PR/CR) until disease progression/recurrence, or up to 1 year after the first dose, whichever occurs first	Efficacy follow-up every 8-12 weeks after the first objective response is confirmed, until the first occurrence of disease progression, recurrence or the 1-year time limit of maintenance therapy
Event-Free Survival (EFS)	Follow-up every 3 months for the first 2 years after surgery and every 6 months for the 3rd year; record the time from the first dose to the first occurrence of any event (disease progression, recurrence, death) or the end of the 3-year follow-up	From the first dose until disease progression/recurrence/death, or up to 3 years after the first dose, whichever occurs first
Overall Survival (OS)	Continuous survival follow-up throughout the study period until the study completion date in February 2029, recording the overall survival time of patients	From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 100 months.
Safety (including treatment-related adverse events, laboratory tests, vital signs, etc.)	Safety assessment once per cycle during the entire treatment period (neoadjuvant + surgery + maintenance); record all adverse events (AEs) and treatment-related adverse events (TRAEs) within 90 days after the last dose;; Long-term safety follow-up at 1 year after the first dose to evaluate delayed immune-related adverse events	1. From the first dose to 90 days after the last dose of study medication (core safety assessment); 2. Long-term safety follow-up up to 1 year after the first dose

Collaborators and Investigators

• Sponsor: Tianjin Medical University Cancer Institute and Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2029

Study Registration Dates

• First Submitted: March 9, 2026
• First Submitted That Met QC Criteria: March 20, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): March 25, 2026
• Last Update Submitted That Met QC Criteria: March 20, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: neoGEJC001

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