Trial · NCT03221426
Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants With Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-585/KEYNOTE-585)
NCT03221426, Phase 3, Completed, Merck Sharp & Dohme LLC; results first posted 2025-02-20
3 sourcestrials-2026-11-12-0.5.0
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ConductScience Library. Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants With Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-585/KEYNOTE-585). Trials, record NCT03221426. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03221426
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants With Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-585/KEYNOTE-585)
- NCT number
- NCT03221426
- Status
- Completed
- Phases
- Phase 3
- Enrollment
- 1,007 participants, actual
- Lead sponsor
- Merck Sharp & Dohme LLC
- Conditions
- Gastric Cancer, Gastroesophageal Junction Cancer
- Interventions
- Pembrolizumab, Placebo, Cisplatin, Capecitabine, 5-fluorouracil, Docetaxel, Oxaliplatin, Leucovorin
- First posted
- 2017-07-18
- Last updated
- 2026-03-09
- Results first posted
- 2025-02-20
Source ClinicalTrials.gov
Registered outcomes10
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Event-free Survival (EFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 75 months | EFS was based on RECIST 1.1 as assessed by the investigator and was defined as the time from randomization to the first of the following events: radiographic disease progression per RECIST 1.1; local or distant recurrence as assessed by computer tomography (CT) scan or biopsy if indicated (for participants who were disease free after surgery); clinical progression as evidenced by peritoneal carcinomatosis confirmed by preoperative laparoscopy or laparotomy (for participants who were confirmed to be free of peritoneal involvement by laparoscopy at screening); or death due to any cause. A second primary malignancy, or radiographic progressive disease (PD) during the neoadjuvant phase that does not preclude successful surgery (i.e., disease free after surgery), were not considered EFS events. |
| Primary | Pathological Complete Response (pathCR) Rate - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 9 weeks following completion of neoadjuvant treatment (up to Study Week 18) | PathCR rate was defined as the percentage of participants having a pathCR based on central review. pathCR was defined as no invasive disease within an entirely submitted and evaluated gross lesion, and histologically negative nodes. The percentage of participants having pathCR was presented for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms. |
| Primary | Overall Survival (OS) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 75 months | OS was defined as the time from randomization to death due to any cause. OS was presented for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms. |
| Primary | Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 70 months | An AE was defined as any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who experience at least one AE was presented for the Pembrolizumab+FLOT and Placebo+FLOT Cohorts. |
| Primary | Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 17 months | An AE was defined as any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who discontinued study treatment due to an AE was presented for the Pembrolizumab+FLOT and Placebo+FLOT Cohorts. |
| Secondary | Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms Separately and in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 89 months | An AE was defined as any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who experienced at least one AE was presented for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms separately and in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts. |
| Secondary | Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms Separately and in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 17 months | An AE was defined as any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who discontinued study treatment due to an AE was presented for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms separately and in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts. |
| Secondary | Disease-free Survival (DFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 75 months | DFS was defined as the time from post-surgery baseline scan until the first occurrence of local or distant recurrence or death from any cause and was based on RECIST 1.1 as assessed by the investigator. |
| Secondary | Overall Survival (OS) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 75 months | OS was defined as the time from randomization to death due to any cause. OS was presented for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts. |
| Secondary | Event-free Survival (EFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 75 months | EFS was based on RECIST 1.1 as assessed by the investigator and was defined as the time from randomization to the first of the following events: radiographic disease progression per RECIST 1.1; local or distant recurrence as assessed by CT scan or biopsy if indicated (for participants who were disease free after surgery); clinical progression as evidenced by peritoneal carcinomatosis confirmed by preoperative laparoscopy or laparotomy (for participants who were confirmed to be free of peritoneal involvement by laparoscopy at screening); or death due to any cause. A second primary malignancy, or radiographic progressive disease (PD) during the neoadjuvant phase that does not preclude successful surgery (i.e., disease free after surgery), were not considered EFS events. |
Source ClinicalTrials.gov
Outcomes10
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Event-free Survival (EFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 75 months | The analysis population consisted of all randomized participants in the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms, as pre-specified per protocol. | Months | MEDIAN |
| PRIMARY | Pathological Complete Response (pathCR) Rate - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 9 weeks following completion of neoadjuvant treatment (up to Study Week 18) | The analysis population consisted of all randomized participants in the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms, as pre-specified per protocol. | Percentage of Participants | NUMBER |
| PRIMARY | Overall Survival (OS) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 75 months | The analysis population consisted of all randomized participants in the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms, as pre-specified per protocol. | Months | MEDIAN |
| PRIMARY | Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 70 months | The analysis population consisted of all participants who received ≥1 dose of study treatment in the Pembrolizumab+FLOT and Placebo+FLOT Cohort treatment arms, as pre-specified per protocol. | Participants | COUNT_OF_PARTICIPANTS |
| PRIMARY | Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 17 months | The analysis population consisted of all participants who received ≥1 dose of study treatment in the Pembrolizumab+FLOT and Placebo+FLOT Cohort treatment arms, as pre-specified per protocol. | Participants | COUNT_OF_PARTICIPANTS |
| SECONDARY | Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms Separately and in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 89 months | The analysis population consisted of all participants who received ≥1 dose of study treatment for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms separately and in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts, as pre-specified per protocol. | Participants | COUNT_OF_PARTICIPANTS |
| SECONDARY | Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms Separately and in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 17 months | The analysis population consisted of all participants who received ≥1 dose of study treatment for the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms separately and in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts, as pre-specified in the protocol. | Participants | COUNT_OF_PARTICIPANTS |
| SECONDARY | Disease-free Survival (DFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Up to approximately 75 months | The analysis population consisted of all randomized participants in the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms who had surgery, as pre-specified per protocol. | Months | MEDIAN |
| SECONDARY | Overall Survival (OS) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 75 months | The analysis population consisted of all randomized participants in the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts, as pre-specified in the protocol. | Months | MEDIAN |
| SECONDARY | Event-free Survival (EFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms in Combination With the Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Up to approximately 75 months | The analysis population consisted of all randomized participants in the Pembrolizumab+XP/FP and Placebo+XP/FP treatment arms in combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts, as pre-specified per protocol. | Months | MEDIAN |
Source ClinicalTrials.gov
Results by group24
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Event-free Survival (EFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Pembrolizumab + XP/FP | 44.4 | 95% Confidence Interval 33.0 to 69.8 | Months | |
| Event-free Survival (EFS) Per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Placebo + XP/FP | 25.7 | 95% Confidence Interval 20.8 to 36.5 | Months | |
| Pathological Complete Response (pathCR) Rate - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Pembrolizumab + XP/FP | 13.4 | 95% Confidence Interval 10.3 to 17.2 | Percentage of Participants | |
| Pathological Complete Response (pathCR) Rate - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Placebo + XP/FP | 2.0 | 95% Confidence Interval 0.9 to 3.9 | Percentage of Participants | |
| Overall Survival (OS) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Pembrolizumab + XP/FP | 71.8 | 95% Confidence Interval 52.5 to NA | Months | |
| Overall Survival (OS) - Pembrolizumab+XP/FP and Placebo+XP/FP Treatment Arms | Placebo + XP/FP | 55.7 | 95% Confidence Interval 41.7 to NA | Months | |
| Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Pembrolizumab + FLOT Cohort | 99 | Participants | ||
| Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Placebo + FLOT Cohort | 103 | Participants | ||
| Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Pembrolizumab + FLOT Cohort | 37 | Participants | ||
| Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Placebo + FLOT Cohort | 26 | Participants |
1 to 10 of 24Source ClinicalTrials.gov
See all 24 results by groupParticipant flow16
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Pembrolizumab + XP/FP | 402 | |
| Overall Study | STARTED | Placebo + XP/FP | 402 | |
| Overall Study | STARTED | Pembrolizumab + FLOT Cohort | 100 | |
| Overall Study | STARTED | Placebo + FLOT Cohort | 103 | |
| Overall Study | Treated | Pembrolizumab + XP/FP | 399 | |
| Overall Study | Treated | Placebo + XP/FP | 400 | |
| Overall Study | Treated | Pembrolizumab + FLOT Cohort | 99 | |
| Overall Study | Treated | Placebo + FLOT Cohort | 103 | |
| Overall Study | COMPLETED | Pembrolizumab + XP/FP | 0 | |
| Overall Study | COMPLETED | Placebo + XP/FP | 0 |
1 to 10 of 16Source ClinicalTrials.gov
See all 16 participant flowAdverse events2,310
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 | Pembrolizumab + XP/FP | 165 | 399 | 228 |
| other | Anaemia | Blood and lymphatic system disorders | Placebo + XP/FP | 158 | 400 | 210 |
| other | Anaemia | Blood and lymphatic system disorders | Pembrolizumab + FLOT Cohort | 25 | 99 | 46 |
| other | Anaemia | Blood and lymphatic system disorders | Placebo + FLOT Cohort | 26 | 103 | 49 |
| other | Anaemia | Blood and lymphatic system disorders | Pembrolizumab + XP/FP and Pembrolizumab + FLOT Combined | 190 | 498 | 274 |
| other | Anaemia | Blood and lymphatic system disorders | Placebo + XP/FP and Placebo + FLOT Combined | 184 | 503 | 259 |
| other | Leukopenia | Blood and lymphatic system disorders | Pembrolizumab + XP/FP | 16 | 399 | 27 |
| other | Leukopenia | Blood and lymphatic system disorders | Placebo + XP/FP | 23 | 400 | 37 |
| other | Leukopenia | Blood and lymphatic system disorders | Pembrolizumab + FLOT Cohort | 5 | 99 | 5 |
| other | Leukopenia | Blood and lymphatic system disorders | Placebo + FLOT Cohort | 5 | 103 | 6 |
1 to 10 of 2,310Source ClinicalTrials.gov
See all 2,310 adverse eventsAdverse event totals18
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Pembrolizumab + XP/FP | 200 | 402 |
| Total, all-cause mortality | Placebo + XP/FP | 225 | 402 |
| Total, all-cause mortality | Pembrolizumab + FLOT Cohort | 40 | 100 |
| Total, all-cause mortality | Placebo + FLOT Cohort | 56 | 103 |
| Total, all-cause mortality | Pembrolizumab + XP/FP and Pembrolizumab + FLOT Combined | 240 | 502 |
| Total, all-cause mortality | Placebo + XP/FP and Placebo + FLOT Combined | 281 | 505 |
| Total, other adverse events | Pembrolizumab + XP/FP | 392 | 399 |
| Total, other adverse events | Placebo + XP/FP | 392 | 400 |
| Total, other adverse events | Pembrolizumab + FLOT Cohort | 99 | 99 |
| Total, other adverse events | Placebo + FLOT Cohort | 103 | 103 |
1 to 10 of 18Source ClinicalTrials.gov
See all 18 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 comparisons2
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison | Source |
|---|---|
| Pembrolizumab + FLOT Cohort vs Placebo + FLOT Cohort: Number of Participants Who Discontinued Study Treatment Due to an AE - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Trial comparisons |
| Pembrolizumab + FLOT Cohort vs Placebo + FLOT Cohort: Number of Participants Who Experienced One or More Adverse Events (AEs) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts | Trial comparisons |
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.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license 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/NCT03221426
GET https://conductscience.org/api/trials/v1/NCT03221426/results?page=2