A Study of ASP2138 Together With Chemotherapy and Pembrolizumab in Adults With Gastric Cancer
Public ClinicalTrials.gov record NCT07673887. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Phase 3, Global, Multi-center, Double-blind, Randomized Study of ASP2138 Plus Chemotherapy (CAPOX or mFOLFOX6) With Pembrolizumab vs Placebo Plus Chemotherapy With or Without Pembrolizumab in First-line Treatment of Locally Advanced Unresectable or Metastatic Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma in Participants Whose Tumors Are HER2-negative and Claudin (CLDN) 18.2-positive
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Claudin 18.2 or CLDN18.2 is a protein found on cells in the digestive system. It is also found in some tumors. Researchers are looking at ways to attack CLDN18.2 to help control tumors. ASP2138 is thought to bind to CLDN18.2 and a type of immune cell called a T cell. This "tells" the immune system to attack the tumor. ASP2138 is a potential treatment for people with gastric cancer (also known as stomach cancer) or gastroesophageal junction cancer (GEJ cancer). GEJ is where the tube that carries food (esophagus) joins the stomach. This study is for people with gastric or GEJ cancer that has spread nearby (locally advanced) and is not removable by surgery (unresectable), or has spread to other parts of the body (metastatic). It is for those whose cancer is human epidermal growth factor receptor 2 (HER2)-negative and CLDN18.2-positive. HER2-negative means the cancer does not have extra HER2 protein, so medicines that target HER2 do not work and are therefore not used. CLDN18.2-positive means people have a certain amount of CLDN18.2 proteins on their cancer cells. In this study, researchers want to learn if ASP2138 given together with standard treatments (chemotherapy and pembrolizumab) help people with HER2-negative and CLDN18.2-positive gastric or GEJ cancer. The main aim is to learn how long people who are given ASP2138 with chemotherapy and pembrolizumab live without their cancer getting worse, compared with placebo given with chemotherapy with or without pembrolizumab, and if they live for longer. Placebo looks like the study treatment but does not have any medicine in it. The main aim of this study is to check how well ASP2138 works when given together with chemotherapy and pembrolizumab compared with placebo plus chemotherapy with or without pembrolizumab. People aged 18 years or older with locally advanced unresectable or metastatic gastric or GEJ cancer can take part. Their tumor should be HER2-negative and CLDN18.2-positive. The study doctors will check people for any health conditions that can exclude them from taking part, interfere with the study procedures, or pose an unacceptable risk. This is a double-blind study. That means the people and the study doctors will not know who will receive which treatment. People will be assigned to one of 2 treatment groups by chance: Group A: People will receive ASP2138 along with chemotherapy and pembrolizumab. Group B: People will receive placebo along with chemotherapy, with or without pembrolizumab. People will keep receiving treatment until their cancer gets worse, they have medical problems that require stopping treatment, or a study rule says they must stop. There will be regular safety checks. People will continue to have scans of their tumor until their cancer becomes worse.
Study identification
- NCT ID
- NCT07673887
- Recruitment status
- Recruiting
- Study type
- Interventional
- Phase
- Phase 3
- Enrollment
- 570 participants
Conditions and interventions
Interventions
- ASP2138 Drug
- Pembrolizumab Drug
- Oxaliplatin Drug
- Capecitabine Drug
- Folinic acid Drug
- 5-FU Drug
- Placebo for ASP2138 Drug
- Placebo for Pembrolizumab Drug
Drug
Eligibility (public fields only)
- Age range
- 18 Years and older
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jun 29, 2026
- Primary completion
- Feb 27, 2031
- Completion
- Feb 27, 2031
- Last update posted
- Sep 10, 2026
2026 – 2031
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Metro Minnesota Community Oncology Research Consortium | Saint Louis Park | Minnesota | 55416 | Recruiting |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
Non-U.S. locations
This page focuses on the U.S. directory. The official record also lists 2 non-U.S. sites.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT07673887, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Sep 10, 2026 · Synced Sep 26, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT07673887 live on ClinicalTrials.gov.