CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 1,579 enrolled
Drug / intervention
Pembrolizumab +5 morebiological
Likely dose
Not stated in record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT03675737
NCT03675737Phase 3Completed

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)

Merck Sharp & Dohme LLC·interventional·Posted Sep 18, 2018·Updated Feb 27, 2026

In Brief

A Phase 3 clinical trial evaluating Pembrolizumab, Cisplatin, and 4 other interventions for Stomach Neoplasms. Completed, enrolled 1,579 participants across 215 sites in 33 countries.

Detailed Summary

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 Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesArgentina, Australia, Brazil, Canada, Chile, China, Colombia, Costa Rica, Czechia, Denmark, France, Germany, Guatemala, Hong Kong, Hungary, Ireland, Israel, Italy, Japan, Mexico, New Zealand, Peru, Poland, Russia, South Africa, South Korea, Spain, Switzerland, Taiwan, Turkey (Türkiye), Ukraine, United Kingdom, United States
Collaborators--

Timeline

Phase 3CompletedFinished
20192020202120222023202420252026
First PostedSep 18, 2018
Enrollment StartNov 8, 2018
Primary CompletionOct 3, 2022
Study CompletionMar 3, 2025
TodayJul 2, 2026
Enrollment to primary: 3.9 yearsPosted 7.8 years ago

Interventions

Pembrolizumabbiological

Administered as an IV infusion on Day 1 Q3W

Cisplatindrug

Administered as an IV infusion on Day 1 Q3W

5-fluorouracildrug

Administered as a continuous IV infusion on Days 1-5 Q3W

oxaliplatindrug

Administered as an IV infusion on Day 1 Q3W

capecitabinedrug

Administered orally BID on Days 1 to 14 Q3W

Placebo for Pembrolizumabdrug

Administered as an IV infusion on Day 1 Q3W