Trial · NCT03615326
Pembrolizumab/Placebo Plus Trastuzumab Plus Chemotherapy in Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Advanced Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-811/KEYNOTE-811)
NCT03615326, Phase 3, Completed, Merck Sharp & Dohme LLC; results first posted 2025-03-17
3 sourcestrials-2026-11-12-0.4.0
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ConductScience Library. Pembrolizumab/Placebo Plus Trastuzumab Plus Chemotherapy in Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Advanced Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-811/KEYNOTE-811). Trials, record NCT03615326. Release trials-2026-11-12-0.4.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03615326
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
Pembrolizumab/Placebo Plus Trastuzumab Plus Chemotherapy in Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Advanced Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-811/KEYNOTE-811)
- NCT number
- NCT03615326
- Status
- Completed
- Phases
- Phase 3
- Enrollment
- 738 participants, actual
- Lead sponsor
- Merck Sharp & Dohme LLC
- Conditions
- Gastric Neoplasms, Gastroesophageal Junction Adenocarcinoma
- Interventions
- Pembrolizumab, Placebo, Cisplatin, 5-FU, Oxaliplatin, Capecitabine, S-1, Trastuzumab
- First posted
- 2018-08-03
- Last updated
- 2026-08-26
- Other registries' IDs
- eudract:2018-000224-34
- Results first posted
- 2025-03-17
Source ClinicalTrials.gov
Registered outcomes6
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Progression Free Survival (PFS) Per RECIST 1.1 Assessed by BICR | Up to 46 months | PFS is defined as the time from randomization to the first documented disease progression per RECIST 1.1 as assessed by BICR or death due to any cause, whichever occurs first. Per RECIST 1.1, progressive disease (PD) is defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of one or more new lesions is also considered progression. PFS was determined for first course pembrolizumab in the Global Cohort. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. |
| Primary | Overall Survival (OS) | Up to 63 months | OS is defined as the time from randomization to death due to any cause. OS was determined for first course pembrolizumab in the Global Cohort. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. |
| Secondary | Objective Response Rate (ORR) Per RECIST 1.1 Assessed by BICR | Up to 63 months | ORR is defined as the percentage of participants who have a Complete Response (\[CR\], disappearance of all evidence of disease) or Partial Response (\[PR\], regression of measurable disease and no new sites) per RECIST 1.1 as assessed by blinded independent central review (BICR). ORR was determined for first course pembrolizumab in the Global Cohort. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. |
| Secondary | Duration of Response (DOR) Per RECIST 1.1 Assessed by BICR | Up to 63 months | For participants who demonstrate CR or PR, DOR is defined as the time from first response (CR or PR) to subsequent disease progression or death from any cause, whichever occurs first. DOR was determined for first course pembrolizumab in the Global Cohort. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. |
| Secondary | Number of Participants Who Experienced an Adverse Event (AE) | Up to 63 months | An AE is any untoward medical occurrence in a participant that is temporally associated with the use of study treatment, whether or not considered related to the study 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 study treatment. The number of participants who experienced an AE is reported for each treatment arm. Per statistical analysis plan, data from the second course of pembrolizumab was not included in the safety analysis. |
| Secondary | Number of Participants Who Discontinued Study Treatment Due to AEs | Up to 63 months | An AE is any untoward medical occurrence in a participant that is temporally associated with the use of study treatment, whether or not considered related to the study 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 study treatment. The number of participants who discontinued study treatment due to an AE is reported for each treatment arm. Per statistical analysis plan, data from the second course of pembrolizumab was not included in the safety analysis. |
Source ClinicalTrials.gov
Outcomes6
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Progression Free Survival (PFS) Per RECIST 1.1 Assessed by BICR | Up to 46 months | All randomized Global Cohort participants in the Pembrolizumab First Course arm and SOC arm were included in this analysis. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. | Months | MEDIAN |
| PRIMARY | Overall Survival (OS) | Up to 63 months | All randomized Global Cohort participants in the Pembrolizumab First Course arm and SOC arm were included in this analysis. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. | Months | MEDIAN |
| SECONDARY | Objective Response Rate (ORR) Per RECIST 1.1 Assessed by BICR | Up to 63 months | All randomized Global Cohort participants in the Pembrolizumab First Course arm and SOC arm were included in this analysis. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. | Percentage of Participants | NUMBER |
| SECONDARY | Duration of Response (DOR) Per RECIST 1.1 Assessed by BICR | Up to 63 months | All randomized Global Cohort participants in the Pembrolizumab First Course arm and SOC arm and who had CR or PR per RECIST 1.1 as assessed by BICR were included in this analysis. Per statistical analysis plan, participants in the Japan-specific SOX Cohort were not included in the efficacy analysis. | Months | MEDIAN |
| SECONDARY | Number of Participants Who Experienced an Adverse Event (AE) | Up to 63 months | All randomized participants in the Global Cohort Pembrolizumab and SOC arms who received at least 1 dose of treatment, and all participants in the Japan-specific SOX Cohort who received at least 1 dose of treatment were included in this analysis. Per statistical analysis plan, data from the second course of pembrolizumab was not included in the safety analysis. | Participants | COUNT_OF_PARTICIPANTS |
| SECONDARY | Number of Participants Who Discontinued Study Treatment Due to AEs | Up to 63 months | All randomized participants in the Global Cohort Pembrolizumab and SOC arms who received at least 1 dose of treatment, and all participants in the Japan-specific SOX Cohort who received at least 1 dose of treatment were included in this analysis. Per statistical analysis plan, data from the second course of pembrolizumab was not included in the safety analysis. | Participants | COUNT_OF_PARTICIPANTS |
Source ClinicalTrials.gov
Results by group16
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Progression Free Survival (PFS) Per RECIST 1.1 Assessed by BICR | Global Pembrolizumab + Standard of Care First Course | 10.0 | 95% Confidence Interval 8.6 to 12.2 | Months | |
| Progression Free Survival (PFS) Per RECIST 1.1 Assessed by BICR | Global Standard of Care | 8.1 | 95% Confidence Interval 7.0 to 8.5 | Months | |
| Overall Survival (OS) | Global Pembrolizumab + Standard of Care First Course | 20.0 | 95% Confidence Interval 17.8 to 22.1 | Months | |
| Overall Survival (OS) | Global Standard of Care First Course | 16.8 | 95% Confidence Interval 14.9 to 18.7 | Months | |
| Objective Response Rate (ORR) Per RECIST 1.1 Assessed by BICR | Global Pembrolizumab + Standard of Care First Course | 72.6 | 95% Confidence Interval 67.6 to 77.2 | Percentage of Participants | |
| Objective Response Rate (ORR) Per RECIST 1.1 Assessed by BICR | Global Standard of Care First Course | 60.1 | 95% Confidence Interval 54.7 to 65.2 | Percentage of Participants | |
| Duration of Response (DOR) Per RECIST 1.1 Assessed by BICR | Global Pembrolizumab + Standard of Care First Course | 11.13 | 95% Confidence Interval 9.8 to 12.7 | Months | |
| Duration of Response (DOR) Per RECIST 1.1 Assessed by BICR | Global Standard of Care First Course | 9.5 | 95% Confidence Interval 7.2 to 11.2 | Months | |
| Number of Participants Who Experienced an Adverse Event (AE) | Global Pembrolizumab + Standard of Care First Course | 348 | Participants | ||
| Number of Participants Who Experienced an Adverse Event (AE) | Global Standard of Care First Course | 346 | Participants |
1 to 10 of 16Source ClinicalTrials.gov
See all 16 results by groupParticipant flow20
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Global Pembrolizumab + Standard of Care First Course | 350 | |
| Overall Study | STARTED | Global Standard of Care | 348 | |
| Overall Study | STARTED | Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin | 20 | |
| Overall Study | STARTED | Japan Trastuzumab + S-1 Plus Oxaliplatin | 20 | |
| Overall Study | Treated | Global Pembrolizumab + Standard of Care First Course | 350 | |
| Overall Study | Treated | Global Standard of Care | 346 | |
| Overall Study | Treated | Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin | 20 | |
| Overall Study | Treated | Japan Trastuzumab + S-1 Plus Oxaliplatin | 20 | |
| Overall Study | Received Second Course of Pembrolizumab | Global Pembrolizumab + Standard of Care First Course | 11 | |
| Overall Study | Received Second Course of Pembrolizumab | Global Standard of Care | 0 |
1 to 10 of 20Source ClinicalTrials.gov
See all 20 participant flowAdverse events1,495
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Anaemia | Blood and lymphatic system disorders | Global Pembrolizumab + Standard of Care First Course | 157 | 350 | 269 |
| other | Anaemia | Blood and lymphatic system disorders | Global Standard of Care | 159 | 346 | 257 |
| other | Anaemia | Blood and lymphatic system disorders | Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin | 5 | 20 | 6 |
| other | Anaemia | Blood and lymphatic system disorders | Japan Trastuzumab + S-1 Plus Oxaliplatin | 4 | 20 | 4 |
| other | Anaemia | Blood and lymphatic system disorders | Global Pembrolizumab + Standard of Care Second Course | 2 | 11 | 4 |
| other | Leukopenia | Blood and lymphatic system disorders | Global Pembrolizumab + Standard of Care First Course | 12 | 350 | 26 |
| other | Leukopenia | Blood and lymphatic system disorders | Global Standard of Care | 23 | 346 | 46 |
| other | Leukopenia | Blood and lymphatic system disorders | Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin | 0 | 20 | 0 |
| other | Leukopenia | Blood and lymphatic system disorders | Japan Trastuzumab + S-1 Plus Oxaliplatin | 0 | 20 | 0 |
| other | Leukopenia | Blood and lymphatic system disorders | Global Pembrolizumab + Standard of Care Second Course | 0 | 11 | 0 |
1 to 10 of 1,495Source ClinicalTrials.gov
See all 1,495 adverse eventsAdverse event totals15
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Global Pembrolizumab + Standard of Care First Course | 264 | 350 |
| Total, all-cause mortality | Global Standard of Care | 288 | 348 |
| Total, all-cause mortality | Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin | 14 | 20 |
| Total, all-cause mortality | Japan Trastuzumab + S-1 Plus Oxaliplatin | 17 | 20 |
| Total, all-cause mortality | Global Pembrolizumab + Standard of Care Second Course | 3 | 11 |
| Total, other adverse events | Global Pembrolizumab + Standard of Care First Course | 345 | 350 |
| Total, other adverse events | Global Standard of Care | 338 | 346 |
| Total, other adverse events | Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin | 20 | 20 |
| Total, other adverse events | Japan Trastuzumab + S-1 Plus Oxaliplatin | 20 | 20 |
| Total, other adverse events | Global Pembrolizumab + Standard of Care Second Course | 9 | 11 |
1 to 10 of 15Source ClinicalTrials.gov
See all 15 adverse event totalsPapers4
The papers the trial lists on ClinicalTrials.gov.
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
None in this release.
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Source
- Release
- trials-2026-11-12-0.4.0
- Release manifest SHA-256
- 0f4a8d8c48aee2a7573ae0fa94ecbeab70c1adbe449bbc95c424bc7d3e97b9d4
- Registry capture
- 2026-11-12
- Results copy, AACT
- 2026-03-23
- NIH clinical studies file
- 2026-11-13
Source ClinicalTrials.gov
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNone stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
GET https://conductscience.org/api/trials/v1/NCT03615326
GET https://conductscience.org/api/trials/v1/NCT03615326/events?page=2