A Study of Neoadjuvant-adjuvant Durvalumab and FLOT Chemotherapy Followed by Adjuvant Durvalumab in Chinese Patients With Resectable GC/GEJC.

A Randomized, Double-blind, Placebo-controlled Study of Neoadjuvant-Adjuvant Durvalumab and FLOT Chemotherapy Followed by Adjuvant Durvalumab in Chinese Patients With Resectable Gastric and Gastroesophageal Junction Cancer (GC/GEJC) (MATTERHORN-CN).

This study aims to assess the efficacy and safety of neoadjuvant adjuvant treatment with durvalumab in combination with FLOT compared to placebo in combination with FLOT in Chinese patients with Resectable Gastric and Gastroesophageal Cancer (GC/GEJC) (MATTERHORN-CN).

Study Overview

• Status: Recruiting
• Conditions: Gastric; Esophagogastric Junction
• Intervention / Treatment: Drug: FLOT Chemotherapy; Drug: Durvalumab

Detailed Description

Informed by the favorable benefit-risk profile demonstrated by the global MATTERHORN study, the current study is designed to assess the efficacy and safety of neoadjuvant-adjuvant durvalumab in combination with FLOT chemotherapy followed by adjuvant durvalumab monotherapy (Arm A), compared with neoadjuvant-adjuvant placebo in combination with FLOT chemotherapy followed by adjuvant placebo monotherapy (Arm B) in Chinese participants with resectable GC/GEJC. Approximately 140 participants will be randomized to either Arm A or Arm B.

• Study Type: Interventional
• Enrollment (Estimated): 140
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: AstraZeneca Clinical Study Information Center; Phone Number: 1-877-240-9479; Email: information.center@astrazeneca.com

Study Locations

• China
  • Beijing, China, 102218
    • Not yet recruiting
    • Research Site
  • Beijing, China, 100050
    • Not yet recruiting
    • Research Site
  • Beijing, China, 100142
    • Recruiting
    • Research Site
  • Beijing, China, 100730
    • Not yet recruiting
    • Research Site
  • Beijing, China, 102206
    • Not yet recruiting
    • Research Site
  • Bengbu, China, 233004
    • Not yet recruiting
    • Research Site
  • Changchun, China, 130021
    • Not yet recruiting
    • Research Site
  • Changchun, China, 130033
    • Recruiting
    • Research Site
  • Changsha, China, 410008
    • Not yet recruiting
    • Research Site
  • Changzhi, China, 046000
    • Not yet recruiting
    • Research Site
  • Chengdu, China, 610041
    • Recruiting
    • Research Site
  • Chengdu, China, 610041
    • Not yet recruiting
    • Research Site
  • Chongqing, China, 400042
    • Not yet recruiting
    • Research Site
  • Fuzhou, China, 350001
    • Not yet recruiting
    • Research Site
  • Guangzhou, China, 510080
    • Not yet recruiting
    • Research Site
  • Guangzhou, China, 510120
    • Not yet recruiting
    • Research Site
  • Guangzhou, China, 510655
    • Not yet recruiting
    • Research Site
  • Hangzhou, China, 310014
    • Recruiting
    • Research Site
  • Hangzhou, China, 310016
    • Not yet recruiting
    • Research Site
  • Hohhot, China, 010020
    • Not yet recruiting
    • Research Site
  • Jinan, China, 250021
    • Not yet recruiting
    • Research Site
  • Jinan, China, 250014
    • Recruiting
    • Research Site
  • Kunming, China, 650118
    • Not yet recruiting
    • Research Site
  • Lanzhou, China, 730000
    • Recruiting
    • Research Site
  • Lanzhou, China, 730030
    • Not yet recruiting
    • Research Site
  • Meizhou, China, 514031
    • Recruiting
    • Research Site
  • Nanchang, China, 330006
    • Not yet recruiting
    • Research Site
  • Nanjing, China, 210029
    • Not yet recruiting
    • Research Site
  • Nanjing, China, 210009
    • Not yet recruiting
    • Research Site
  • Nanning, China, 530021
    • Not yet recruiting
    • Research Site
  • Qingdao, China, 266003
    • Recruiting
    • Research Site
  • Shanghai, China, 200032
    • Not yet recruiting
    • Research Site
  • Shanghai, China, 201210
    • Not yet recruiting
    • Research Site
  • Shanghai, China, 200031
    • Not yet recruiting
    • Research Site
  • Shaoguan, China, 512027
    • Recruiting
    • Research Site
  • Shenyang, China, 110042
    • Not yet recruiting
    • Research Site
  • Suining Shi, China, 629000
    • Recruiting
    • Research Site
  • Taiyuan, China, 030000
    • Not yet recruiting
    • Research Site
  • Wuhan, China, 430030
    • Not yet recruiting
    • Research Site
  • Xi'an, China, 710068
    • Recruiting
    • Research Site
  • Zhengzhou, China, 450000
    • Not yet recruiting
    • Research Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 1. Capable of giving signed informed consent. 2. Male and/or Female, Age ≥ 18 years at the time of screening. 3. Histologically documented gastric or gastroesophageal junction adenocarcinoma with resectable disease, GEJC includes Siewert* type 2 and 3 tumour and Siewert* type 1 tumour.

  1. Per the judgment of the Investigator, participants must be medically fit for treatment with neoadjuvant FLOT therapy prior to radical surgery.

  2. At screening, complete surgical resection of the primary GC/GEJC must be deemed achievable, as assessed by a multidisciplinary evaluation, which must include a board certified GI surgeon.

  3. No prior anti-cancer therapy (eg, chemotherapy, radiation therapy, or chemoradiation therapy) for the current malignancy.

     4. ECOG PS of 0 or 1 with no deterioration over the previous 2 weeks prior to baseline at screening and prior to randomization.

     5. Adequate organ and marrow function as defined below:

  1. Haemoglobin ≥ 9.0 g/dL
  2. Absolute neutrophil count ≥ 1.5 × 109/L
  3. Platelet count ≥ 100 × 109/L
  4. Serum bilirubin ≤ 1.5 ×ULN. This will not apply to participants with confirmed Gilbert's syndrome, who will be allowed in consultation with their physician.
  5. ALT and AST ≤ 2.5 × ULN
  6. Measured CL > 50 mL/min or Calculated CL > 50 mL/min as determined by Cockcroft-Gault (using actual body weight) 6. Must have a life expectancy of at least 24 weeks. 7. Body weight > 30 kg at enrolment and randomization. 8. Meeting tumour sample requirements (at screening) to confirm PD-L1 status.

Exclusion Criteria:

• -1. Participants with peritoneal dissemination (including tumour cells in peritoneal fluid) or distant metastasis.

  2. Participants with adenosquamous cell carcinoma, squamous cell carcinoma, or GI stromal tumour.

  3. History of allogeneic organ transplantation. 4. Active or prior documented autoimmune or inflammatory disorders (including inflammatory bowel disease [eg, colitis or Crohn's disease], systemic lupus erythematosus, sarcoidosis, granulomatosis with polyangiitis, Graves' disease, rheumatoid arthritis, hypophysitis, uveitis, etc), autoimmune pneumonitis, and autoimmune myocarditis.

  5. Uncontrolled intercurrent illness that would limit compliance with study requirement, substantially increase risk of incurring AEs or compromise the ability of the patient to give written informed consent.

  6. History of another primary malignancy except for

  (a) Malignancy treated with curative intent and with no known active disease ≥ 2 years before the first dose of study intervention and of low potential risk for recurrence (b) Adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease (c) Adequately treated carcinoma in situ without evidence of disease 7. History of active primary immunodeficiency. 8. Active infection including tuberculosis (clinical evaluation that includes clinical history, physical examination and radiographic findings, and tuberculosis testing in line with local practice) and HIV verified by positive HIV-1 or HIV-2 antibodies.

  9. Mean QTc ≥ 470 ms calculated from 3 ECGs (within 15 minutes at 5 minutes apart).

  10. Known allergy or hypersensitivity to any of the study interventions or any of the study intervention excipients.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm A; Durvalumab +FLOT followed by durvalumab	Drug: FLOT Chemotherapy; A combination treatment made up of flurouroacil + leucovorin + oxaliplatin + docetaxel; Drug: Durvalumab; Human monoclonal antibody
Placebo Comparator: Arm B; Placebo +FLOT followed by Placebo	Drug: FLOT Chemotherapy; A combination treatment made up of flurouroacil + leucovorin + oxaliplatin + docetaxel

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To compare Arm A relative to Arm B on pCR rate	pCR rate is defined as the proportion of participants who have no residual viable tumour in the resected specimens and as determined by central pathology review.	Up to 24 months after the last participant is randomized

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To compare Arm A relative to Arm B on event-free survival at 24 months (EFS24)	EFS24 is the proportion of participants alive and event free 24 months after randomization, according to Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 per Investigator assessment and/or locally by pathology testing.	Up to 24 months after the last participant is randomized
To compare Arm A relative to Arm B on overall survival (OS)	Overall survival is length of time from randomization until the date of death due to any cause.	Up to 24 months after the last participant is randomized
To compare Arm A relative to Arm B on event-free survival (EFS)	EFS is defined as the time from randomization to the following, according to RECIST 1.1 per Investigator assessment and/or locally by pathology testing: Progression that precludes surgery or requires non-protocol therapy,; Local or distant recurrence or progression of disease, or 3) Death due to any cause.	Up to 24 months after the last participant is randomized
To compare Arm A relative to Arm B on the rate of complete resection (R0)	R0 resection (complete resection) rate is the proportion of participants who have a confirmed complete resection as assessed by pathology review.	Up to 24 months after the last participant is randomized
To compare Arm A relative to Arm B on metastasis-free survival (MFS) and disease-specific survival (DSS)	MFS is the time from randomization until the development of metastasis using RECIST 1.1 or death due to any cause. • DSS is the time from randomization untildeath due to GC/GEJC.	Up to 24 months after the last participant is randomized
To compare Arm A relative to Arm B on disease-free survival (DFS) in participants who undergo R0 resection surgery	DFS is defined as the time from first post-surgery scan until disease recurrence, using RECIST 1.1, or death due to any cause.	Up to 24 months after the last participant is randomized

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the safety and tolerability of Arm A as compared to Arm B in participants with GC/GEJC	Safety and tolerability will be evaluated in terms of adverse events (AEs)	Up to 24 months after the last participant is randomized

Collaborators and Investigators

• Sponsor: AstraZeneca

Study record dates

Study Major Dates

• Study Start (Actual): October 9, 2026
• Primary Completion (Estimated): November 1, 2029
• Study Completion (Estimated): November 1, 2029

Study Registration Dates

• First Submitted: September 15, 2026
• First Submitted That Met QC Criteria: October 9, 2026
• First Posted (Actual): October 16, 2026

Study Record Updates

• Last Update Posted (Actual): November 6, 2026
• Last Update Submitted That Met QC Criteria: November 4, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: Durvalumab; FLOT chemotherapy
• Additional Relevant MeSH Terms: durvalumab
• Other Study ID Numbers: D907JC00001

Plan for Individual participant data (IPD)

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

IPD Plan Description

IPD will be sharedQualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared. upon certain conditions.

IPD Sharing Time Frame

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA PhRMA Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

IPD Sharing Access Criteria

When a request has been approved AstraZeneca will provide access to the anonymized individual patient-level data via secure research environment Vivli.org. Signed Data Usage Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information.

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No