Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-859/KEYNOTE-859)
Public ClinicalTrials.gov record NCT03675737. 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, Randomized, Double-blind Clinical Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy as First-line Treatment in Participants With HER2 Negative, Previously Untreated, Unresectable or Metastatic Gastric Orgastroesophageal Junction Adenocarcinoma (KEYNOTE-859)
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
The purpose of this study is to evaluate the efficacy of pembrolizumab (MK-3745) in combination with chemotherapy (Cisplatin combined with 5-Fluorouracil \[FP regimen\] or oxaliplatin combined with capecitabine \[CAPOX regimen\]) versus placebo in combination with chemotherapy (FP or CAPOX regimens) in the treatment of human epidermal growth factor receptor 2 (HER2) negative advanced gastric or GEJ adenocarcinoma in adult participants. The primary hypotheses of this study are that pembrolizumab plus chemotherapy is superior to placebo plus chemotherapy in terms of overall survival (OS). Once a participant has achieved the study objective or the study has ended, the participant will be discontinued from this study and enrolled in an extension study (Keynote 587; NCT03486873) to continue protocol-defined assessments and treatment.
Study identification
- NCT ID
- NCT03675737
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 3
- Enrollment
- 1,579 participants
Conditions and interventions
Conditions
Interventions
- Pembrolizumab Biological
- Cisplatin Drug
- 5-fluorouracil Drug
- oxaliplatin Drug
- capecitabine Drug
- Placebo for Pembrolizumab Drug
Biological · 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
- Nov 7, 2018
- Primary completion
- Oct 2, 2022
- Completion
- Mar 2, 2025
- Last update posted
- Feb 26, 2026
2018 – 2025
United States locations
- U.S. sites
- 10
- U.S. states
- 8
- U.S. cities
- 10
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| UCLA Hematology/Oncology - Westwood (Building 200 Suite 120) ( Site 0124) | Los Angeles | California | 90095 | — |
| UC Irvine Health/Division of Hematology Oncology, Dept of Medicine ( Site 0128) | Orange | California | 92868 | — |
| University of Miami, Sylvester Comprehensive Cancer Center ( Site 0113) | Miami | Florida | 33136 | — |
| Greater Baltimore Medical Center ( Site 0102) | Baltimore | Maryland | 21204 | — |
| Minnesota Oncology Hematology, PA ( Site 8000) | Minneapolis | Minnesota | 55404 | — |
| University of Rochester ( Site 0122) | Rochester | New York | 14642 | — |
| Cancer Treatment Centers of America - Philadelphia ( Site 0112) | Philadelphia | Pennsylvania | 19124 | — |
| Allegheny General Hospital ( Site 0118) | Pittsburgh | Pennsylvania | 15212 | — |
| Oncology & Hematology Assoc. SW Virginia, Inc., DBA Blue Ridge Cancer Care ( Site 8001) | Roanoke | Virginia | 24014 | — |
| Wenatchee Valley Clinic [Wenatchee, WA] ( Site 0116) | Wenatchee | Washington | 98801 | — |
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 205 non-U.S. sites.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT03675737, 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 Feb 26, 2026 · Synced Sep 10, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT03675737 live on ClinicalTrials.gov.