A Study to Observe the Safety of VYLOY (Zolbetuximab) in People in South Korea With Gastric or Gastroesophageal Junction Cancer.

August 25, 2026 updated by: Astellas Pharma Korea, Inc.

Post-marketing Observational Study of VYLOY (Zolbetuximab) Injection 100 mg, 300 mg for Locally Advanced Unresectable or Metastatic Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma in South Korea

This study is for people in South Korea who have cancer in or around the stomach (gastric cancer) or cancer where the food pipe (esophagus) joins the stomach, called gastroesophageal junction (GEJ) cancer. Their cancer is locally advanced, unresectable, or metastatic. Locally advanced means the cancer has spread to tissue close by. Unresectable means the cancer cannot be removed by surgery. Metastatic means the cancer has spread to other parts of the body.

In South Korea, VYLOY is approved for the treatment of gastric cancer or GEJ cancer. The people in this study will receive VYLOY as part of their usual treatment for their cancer. In standard clinical practice VYLOY is given to people slowly through a tube into a vein.

The main aim of the study is to collect information in a real-world setting about the safety of VYLOY in people with gastric cancer or GEJ cancer in clinics in South Korea. This study will also help researchers learn how long people's gastric cancer or GEJ cancer stays stable.

This study is about collecting information only. This is known as an observational study. The individual's doctor decides on treatment, not the sponsor (Astellas). The study will last about 1 year (54 weeks).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

377

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • South Korea
      • Daejeon, South Korea
        • Recruiting
        • KR82015
      • Seoul, South Korea
        • Recruiting
        • KR82001
      • Seoul, South Korea
        • Recruiting
        • KR82002
      • Seoul, South Korea
        • Recruiting
        • KR82003
      • Seoul, South Korea
        • Recruiting
        • KR82004
      • Seoul, South Korea
        • Recruiting
        • KR82005
      • Seoul, South Korea
        • Recruiting
        • KR82011
      • Seoul, South Korea
        • Recruiting
        • KR82007
      • Seoul, South Korea
        • Recruiting
        • KR82013
    • Gyeonggi-do
      • Goyang-si, Gyeonggi-do, South Korea
        • Recruiting
        • KR82010
      • Suwon, Gyeonggi-do, South Korea
        • Recruiting
        • KR82008
      • Suwon, Gyeonggi-do, South Korea
        • Recruiting
        • KR82009
    • Gyeongsangnam-do
      • Yangsan, Gyeongsangnam-do, South Korea
        • Recruiting
        • KR82006
    • Jeollanam-do
      • Hwasun Gun, Jeollanam-do, South Korea
        • Recruiting
        • KR82012

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients who have locally advanced unresectable or metastatic HER2-negative, and CLDN18.2-positive, gastric or GEJ adenocarcinoma who are prescribed VYLOY injection in combination with fluoropyrimidine- and platinum-containing chemotherapy for the first line treatment in South Korea.

Description

Inclusion Criteria:

  • Patients who receive treatment with VYLOY injection, according to the approved local label.

Exclusion Criteria:

  • Patients with any contraindication for VYLOY injection, according to the approved local label.
  • Patients who are registered or scheduled to be registered in any clinical trials involving investigational drug administration.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Vyloy
Patients who receive treatment with Vyloy injection 100 mg or 300 mg (zolbetuximab), according to the approved local label.
Drug: zolbetuximab
Intravenous
Other Names:
  • Vyloy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of patients with an adverse event (AE)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
Adverse events (AEs) will be coded using MedDRA. An AE is defined as any untoward medical occurrence in a patient administered a study drug, and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a medicinal product whether or not considered related to the medicinal product.
Up to 54 Weeks after the first administration of VYLOY
Number of patients with an adverse drug reaction (ADR)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
An ADR is defined as any noxious and unintended response associated with the use of a drug in humans, at any dose, where a causal relationship is at least a reasonable possibility.
Up to 54 Weeks after the first administration of VYLOY
Number of patients with a serious AE (SAE)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
An AE is considered "serious" if, in the view of either the investigator or sponsor, the event: results in death, is life-threatening, requires hospitalization or prolongation to hospitalization results in persistent or significant disability or incapacity, results in congenital anomaly or birth defect, or other medically important event.
Up to 54 Weeks after the first administration of VYLOY
Number of patients with a serious ADR (SADR)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
An ADR considered "serious" if, in the view of either the investigator or sponsor, the event: results in death, is life-threatening, requires hospitalization or prolongation to hospitalization results in persistent or significant disability or incapacity, results in congenital anomaly or birth defect, or other medically important event.
Up to 54 Weeks after the first administration of VYLOY
Number of patients with an unexpected AE (UAE)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
An UAE is an AE that the nature or severity of which is not consistent with the information in the Precautions in Use Section of approved Korean label.
Up to 54 Weeks after the first administration of VYLOY
Number of patients with an unexpected ADR (UADR)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
An UADR is defined as an unexpected adverse drug reaction.
Up to 54 Weeks after the first administration of VYLOY
Number of patients who died during the study
Time Frame: Up to 54 Weeks after the first administration of VYLOY
Up to 54 Weeks after the first administration of VYLOY
Number patients with an AE leading to death
Time Frame: Up to 54 Weeks after the first administration of VYLOY
Up to 54 Weeks after the first administration of VYLOY
Number of patients with an important risk compared to number of patients evaluated
Time Frame: Up to 54 Weeks after the first administration of VYLOY

An important risk is classified as an important identified risk and an important potential risk.

An identified risk is defined as the risk that correspond to undesirable clinical outcomes, with sufficient scientific evidence that the undesirable clinical outcome is caused by the drug. "Important Identified Risks" are identified risks that have the potential to affect the risk-benefit balance of a product.

An potential risk is defined as the risk that correspond to undesirable clinical outcomes, with some, but not sufficient, evidence to estimate that the undesirable clinical outcome is caused by the drug. "Important Potential Risks" are potential risks that have the potential to affect the risk-benefit balance of a product.
Up to 54 Weeks after the first administration of VYLOY

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression free survival (PFS)
Time Frame: Up to 54 Weeks after the first administration of VYLOY
PFS is defined as time from start of VYLOY to progressive disease (PD) or death from any cause, whichever occurs first.
Up to 54 Weeks after the first administration of VYLOY

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Astellas Pharma Korea, Inc.

Investigators

  • Study Director: Central Contact, Astellas Pharma Korea, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 3, 2025

Primary Completion (Estimated)

July 31, 2030

Study Completion (Estimated)

July 31, 2030

Study Registration Dates

First Submitted

March 24, 2025

First Submitted That Met QC Criteria

March 24, 2025

First Posted (Actual)

March 30, 2025

Study Record Updates

Last Update Posted (Actual)

August 26, 2026

Last Update Submitted That Met QC Criteria

August 25, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 8951-PV-0001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Access to anonymized individual participant level data will not be provided for this trial. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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