NCT06731478 · Daiichi Sankyo
Study of TDXd, Chemotherapy, Pembrolizumab, and Trastuzumab in First-Line Metastatic HER2-Positive Gastric or Gastroesophageal Junction Cancer
What this study is about
This clinical trial is designed to assess the effectiveness and safety of the triplet combination of trastuzumab deruxtecan (ENHERTU, T-DXd, DS-8201a) plus a fluoropyrimidine plus pembrolizumab versus the usual treatment (SoC) chemotherapy plus trastuzumab plus pembrolizumab as first-line therapy in participants with unresectable, locally advanced or metastatic HER2-positive tumor PD-L1 CPS ≥1 gastric or GEJ cancer in the Main group of participants. An Exploratory group of participants will also be evaluated to assess the effectiveness a
View original scientific description
This clinical trial is designed to assess the efficacy and safety of the triplet combination of trastuzumab deruxtecan (ENHERTU, T-DXd, DS-8201a) plus a fluoropyrimidine plus pembrolizumab versus standard of care (SoC) chemotherapy plus trastuzumab plus pembrolizumab as first-line therapy in participants with unresectable, locally advanced or metastatic HER2-positive tumor PD-L1 CPS ≥1 gastric or GEJ cancer in the Main Cohort.
Interventions
DRUG
Trastuzumab Deruxtecan
T-DXd will be administered at a dose of 5.4 mg/kg intravenously (IV) every 3 weeks (Q3W)
DRUG
pembrolizumab
Pembrolizumab will be administered at a dose of 200 mg IV Q3W
DRUG
Trastuzumab
Trastuzumab will be administered at a loading dose of 8 mg/kg IV followed by 6 mg/kg IV Q3W
DRUG
Chemotherapy
For Arms M1 and E1: 5-FU or capecitabine will be administered. For Arms M2 and E2: Cisplatin plus 5-FU or oxaliplatin plus capecitabine will be administered.
Primary outcome measures
Progression Free Survival (PFS)
Time frame: From date of randomization to the date of radiographic disease progression or death due to any cause, up to 59 months
PFS is defined as the time interval from the date of randomization to the date of radiographic disease progression as assessed by blinded independent central review (BICR) based on RECIST v1.1 or death due to any cause.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Sign and date the Tissue Prescreening ICF, prior to HER2 and PD-L1 CPS central testing. Sign and date the Main Screening ICF, prior to the start of any trial-specific qualification procedures. Sign and date the Optional PGx ICF (included in the Main Screening ICF) prior to any PGx procedure. 2. Adults ≥18 years of age on the day of signing the ICF. Follow local regulatory requirements if the legal age of consent for trial participation is \>18 years old. 3. Previously untreated, unresectable, locally advanced or metastatic gastric or GEJ adenocarcinoma histologically confirmed by pathology report. Prior treatment in the perioperative and/or adjuvant setting is permissible, provided there is \>6 months between the end of perioperative or neoadjuvant treatment and the diagnosis of recurrent disease. Note: Prior use of IO (ie, anti-PD-1/PD-L1) therapy in the (neo)adjuvant setting is allowed as long as there is \>6 months between the end of IO therapy and the diagnosis of
Where
- New Haven, Connecticut
- Skokie, Illinois
- Kansas City, Kansas
- Silver Spring, Maryland
- Boston, Massachusetts
- Ann Arbor, Michigan
- Minneapolis, Minnesota
- New York, New York
- The Bronx, New York
- Portland, Oregon
- Hershey, Pennsylvania
- Greenville, South Carolina
And 6 more locations — see the full list below.
Collaborators
Merck Sharp & Dohme LLC
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 15, 2026 · Source of record for eligibility and locations