Gastric / Gastroesophageal Junction AdenocarcinomaPhase 2Pre-CATALISNCT07259473
Factors Influencing Immunotherapy Response in dMMR/MSI-H Gastric/Gastroesophageal Junction Adenocarcinoma
A Phase 2 study testing Immunotherapy, Induction chemotherapy and D2 radical gastrectomy in people with Gastric / Gastroesophageal Junction Adenocarcinoma and Mismatch Repair Deficient or MSI-High Solid Tumors, run by Shanghai Zhongshan Hospital.
Trial summary
dMMR/MSI-H is a key molecular subtype of gastric cancer, found in 8-22% of cases. It is typically associated with older age, female sex, distal tumor location, and intestinal histology (Lauren classification). Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Gastric / Gastroesophageal Junction Adenocarcinoma, Mismatch Repair Deficient or MSI-High Solid Tumors, Immunotherapy
- What is being tested?
- Immunotherapy, Induction chemotherapy and D2 radical gastrectomy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- No sites listed yet
- Study dates
- 31 Jan 2026to 30 Dec 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or female, aged 18 to 85 years.
- Histologically confirmed gastric cancer or adenocarcinoma of the esophagogastric junction (only Siewert types II and III are included).
- dMMR status confirmed by immunohistochemistry (IHC) or MSI-H status confirmed by PCR/NGS.
- Tumor clinical staging meeting the following criteria:
- cT≥2, any N, M0, assessed by the investigator as potentially resectable and planned for preoperative treatment followed by surgery.
- Willing to receive treatment with immune checkpoint inhibitors (including, but not limited to, various PD-1 inhibitors, PD-L1 inhibitors, CTLA-4 inhibitors, PD-1/CTLA-4 bispecific antibodies, etc.), which may be combined with or without standard chemotherapy regimens for gastric cancer.
Who cannot join
- Tumor histology other than adenocarcinoma, such as squamous cell carcinoma, neuroendocrine carcinoma, etc.
- Presence of central nervous system metastases and/or leptomeningeal carcinomatosis.
- Prior antitumor therapy directed at the current gastric cancer (excluding palliative gastrointestinal bypass surgery performed to relieve obstructive symptoms).
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Factors Influencing Immunotherapy Response in Mismatch Repair Deficiency (dMMR) / Microsatellite Instability-High (MSI-H) Gastric/Gastroesophageal Junction Adenocarcinoma
dMMR/MSI-H is a key molecular subtype of gastric cancer, found in 8-22% of cases. It is typically associated with older age, female sex, distal tumor location, and intestinal histology (Lauren classification). While this subtype predicts better survival in locally advanced disease, its prognostic role in metastatic settings is less clear.
Notably, dMMR/MSI-H tumors are often resistant to conventional chemotherapy. Conversely, they demonstrate exceptional sensitivity to immunotherapy. This has led to effective strategies using immune checkpoint inhibitors, either alone or combined with chemotherapy, in both neoadjuvant and advanced disease settings.
However, key challenges remain. Prospective data are largely from Western populations, leaving the efficacy in Asian patients-who bear a high disease burden-less defined. Furthermore, about half of dMMR/MSI-H patients exhibit primary or acquired resistance to immunotherapy. A deeper understanding of the tumor-immune dynamics during treatment is crucial to uncover resistance mechanisms and improve patient outcomes.
- Conditions
- Gastric / Gastroesophageal Junction Adenocarcinoma, Mismatch Repair Deficient or MSI-High Solid Tumors, Immunotherapy
- Being tested
- Immunotherapy, Induction chemotherapy, D2 radical gastrectomy
- Medical subject headings
- Turcot syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ImmunotherapyDrug
Drug: Immune checkpoint inhibitors (ICIs), specifically PD-1 antibodies, PD-L1 antibodies, PD-1/CTLA-4 bispecific antibodies, or PD-1/CTLA-4 combination therapy.
Regimen: 4 treatment cycles.
Induction chemotherapyDrug
Drug: Oxaliplatin Regimen: 1 cycle Dosage: 130mg/m^2
D2 radical gastrectomyProcedure or surgery
Curative-intent D2 radical gastrectomy is scheduled 4-6 weeks after completion of the fourth cycle.
| Study group | Role | What they receive |
|---|---|---|
| dMMR/MSI-H GC | Experimental | Immunotherapy with induction chemotherapy Receives: Drug: Immunotherapy; Drug: Induction chemotherapy; Procedure: D2 radical gastrectomy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of pathological complete response
The proportion of subjects exhibiting no residual tumor cells in the surgical specimen and the absence of positive lymph nodes (i.e., a pathological stage of ypT0N0).
Measured: From the initiation of treatment to the date of surgery, an average of 14 weeks.
Secondary outcomes (5)
Major Pathological Response Rate
The proportion of subjects with residual viable tumor cells accounting for <10% of the surgical specimen from the primary tumor site.
Measured: From the initiation of treatment to the date of surgery, an average of 14 weeks.
ypN stage
Lymph-node status after neoadjuvant therapy (ypN stage) will be assessed according to the American Joint Committee on Cancer (AJCC) 8th edition staging system.
Measured: From the initiation of treatment to the date of surgery, an average of 14 weeks.
R0 resection rate
The proportion of patients who undergo surgery with microscopically negative resection margins.
Measured: From the initiation of treatment to the date of surgery, an average of 14 weeks.
Event-free Survival
The time from the subject's enrollment until disease progression, disease recurrence, or death from any cause.
Measured: The time from the initiation of treatment until disease progression, disease recurrence, death from any cause, or 3 years since enrollment.
Overall Survival
The time from the subject's enrollment until death from any cause.
Measured: From the initiation of treatment until death from any cause or 3 years since enrollment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2025
- Study start31 Jan 2026 (estimated)
- Primary completion30 Dec 2029 (estimated)
- Study completion30 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gastric / Gastroesophageal Junction AdenocarcinomaStudies of the same condition, open and under way.
- More trials run by Shanghai Zhongshan HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Shanghai Zhongshan Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Xuefei.Wang, Shanghai Zhongshan Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07259473
- Sponsor's protocol ID
- B2025-541R
- Acronym
- Pre-CATALIS
- Status last verified
- Jan 2026
- First submitted
- 19 Nov 2025
- Last updated
- 7 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Informed consent forms did not include provisions for public data sharing
Study at a glance
From the registry record, last updated by the sponsor on 7 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Factors Influencing Immunotherapy Response in Mismatch Repair Deficiency (dMMR) / Microsatellite Instability-High (MSI-H) Gastric/Gastroesophageal Junction Adenocarcinoma
- ClinicalTrials.gov ID
- NCT07259473
- Acronym / sponsor ID
- Pre-CATALIS / B2025-541R
- Conditions
- Gastric / Gastroesophageal Junction Adenocarcinoma, Mismatch Repair Deficient or MSI-High Solid Tumors, Immunotherapy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- Shanghai Zhongshan HospitalUniversity, hospital or other
- Study start
- 31 Jan 2026 (estimated)
- Primary completion
- 30 Dec 2029 (estimated)
- Study completion
- 30 Dec 2029 (estimated)
- First posted
- 2 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
dMMR/MSI-H is a key molecular subtype of gastric cancer, found in 8-22% of cases. It is typically associated with older age, female sex, distal tumor location, and intestinal histology (Lauren classification). While this subtype predicts better survival in locally advanced disease, its prognostic role in metastatic settings is less clear.
Notably, dMMR/MSI-H tumors are often resistant to conventional chemotherapy. Conversely, they demonstrate exceptional sensitivity to immunotherapy. This has led to effective strategies using immune checkpoint inhibitors, either alone or combined with chemotherapy, in both neoadjuvant and advanced disease settings.
However, key challenges remain. Prospective data are largely from Western populations, leaving the efficacy in Asian patients-who bear a high disease burden-less defined. Furthermore, about half of dMMR/MSI-H patients exhibit primary or acquired resistance to immunotherapy. A deeper understanding of the tumor-immune dynamics during treatment is crucial to uncover resistance mechanisms and improve patient outcomes.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| dMMR/MSI-H GC | Experimental | Drug: Immunotherapy, Drug: Induction chemotherapy, Procedure: D2 radical gastrectomyImmunotherapy with induction chemotherapy |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Male or female, aged 18 to 85 years.
- Histologically confirmed gastric cancer or adenocarcinoma of the esophagogastric junction (only Siewert types II and III are included).
- dMMR status confirmed by immunohistochemistry (IHC) or MSI-H status confirmed by PCR/NGS.
- Tumor clinical staging meeting the following criteria:
- cT≥2, any N, M0, assessed by the investigator as potentially resectable and planned for preoperative treatment followed by surgery.
Key exclusion criteria (3 listed)
- Tumor histology other than adenocarcinoma, such as squamous cell carcinoma, neuroendocrine carcinoma, etc.
- Presence of central nervous system metastases and/or leptomeningeal carcinomatosis.
- Prior antitumor therapy directed at the current gastric cancer (excluding palliative gastrointestinal bypass surgery performed to relieve obstructive symptoms).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ImmunotherapyDrug: Immune checkpoint inhibitors (ICIs), specifically PD-1 antibodies, PD-L1 antibodies, PD-1/CTLA-4 bispecific antibodies, or PD-1/CTLA-4 combination therapy. Regimen: 4 treatment cycles. | Drug | dMMR/MSI-H GC |
| Induction chemotherapyDrug: Oxaliplatin Regimen: 1 cycle Dosage: 130mg/m^2 | Drug | dMMR/MSI-H GC |
| D2 radical gastrectomyCurative-intent D2 radical gastrectomy is scheduled 4-6 weeks after completion of the fourth cycle. | Procedure or surgery | dMMR/MSI-H GC |
Primary outcome
Rate of pathological complete response
Time frame: From the initiation of treatment to the date of surgery, an average of 14 weeks.
The proportion of subjects exhibiting no residual tumor cells in the surgical specimen and the absence of positive lymph nodes (i.e., a pathological stage of ypT0N0).
5 secondary outcomes
Major Pathological Response Rate
Time frame: From the initiation of treatment to the date of surgery, an average of 14 weeks.
ypN stage
Time frame: From the initiation of treatment to the date of surgery, an average of 14 weeks.
R0 resection rate
Time frame: From the initiation of treatment to the date of surgery, an average of 14 weeks.
Event-free Survival
Time frame: The time from the initiation of treatment until disease progression, disease recurrence, death from any cause, or 3 years since enrollment.
Overall Survival
Time frame: From the initiation of treatment until death from any cause or 3 years since enrollment.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jan 2026.
- Individual participant dataSharing planned: No. Informed consent forms did not include provisions for public data sharing
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Immunotherapy, Induction chemotherapy and D2 radical gastrectomy in people with Gastric / Gastroesophageal Junction Adenocarcinoma and Mismatch Repair Deficient or MSI-High Solid Tumors, run by Shanghai Zhongshan Hospital.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 7 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Zhaoqing Tang (021-64041990, tang.zhaoqing@zs-hospital.sh.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of pathological complete response (time frame: From the initiation of treatment to the date of surgery, an average of 14 weeks.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jan 2026.