Trial · NCT03382600
Safety and Efficacy of Pembrolizumab (MK-3475) in Combination With TS-1+Cisplatin or TS-1+Oxaliplatin as First Line Chemotherapy in Gastric Cancer (MK-3475-659/KEYNOTE-659)
NCT03382600, Phase 2, Completed, Merck Sharp & Dohme LLC; results first posted 2023-12-01
3 sourcestrials-2026-11-12-0.4.0
Download JSON
Cite this record
ConductScience Library. Safety and Efficacy of Pembrolizumab (MK-3475) in Combination With TS-1+Cisplatin or TS-1+Oxaliplatin as First Line Chemotherapy in Gastric Cancer (MK-3475-659/KEYNOTE-659). Trials, record NCT03382600. Release trials-2026-11-12-0.4.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03382600
On this page
Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- Safety and Efficacy of Pembrolizumab (MK-3475) in Combination With TS-1+Cisplatin or TS-1+Oxaliplatin as First Line Chemotherapy in Gastric Cancer (MK-3475-659/KEYNOTE-659)
- NCT number
- NCT03382600
- Status
- Completed
- Phases
- Phase 2
- Enrollment
- 100 participants, actual
- Lead sponsor
- Merck Sharp & Dohme LLC
- Conditions
- Gastric Cancer
- Interventions
- Pembrolizumab, Oxaliplatin, TS-1, Cisplatin
- First posted
- 2017-12-26
- Last updated
- 2024-06-11
- Results first posted
- 2023-12-01
Source ClinicalTrials.gov
Registered outcomes13
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Objective Response Rate (ORR) According to Response Evaluation Criteria In Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) | Up to ~36 months | For the primary efficacy analysis, ORR was defined as the percentage of participants who have a best response of complete response (CR, disappearance of all target lesions) or partial response (PR, at least a 30% decrease in the sum of diameters \[SOD\] of target lesions, taking as reference the baseline SOD) per RECIST 1.1 as assessed by BICR. |
| Secondary | ORR According to Immune-related Response Evaluation Criteria In Solid Tumors (iRECIST) Assessed by BICR | Up to ~36 months | For the secondary efficacy analysis, ORR was defined as the percentage of participants whose best response based on imaging is CR (disappearance of all target lesions) or PR (≥30% decrease in the SOD of target lesions, taking as reference the baseline SOD) according to iRECIST as assessed by BICR. iRECIST is a modification to RECIST that takes into account unique patterns of atypical response in immunotherapy and enables treatment beyond initial radiographic progression. |
| Secondary | Duration of Response (DOR) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | For participants who demonstrated complete response (CR, disappearance of all target lesions) or partial response (PR, ≥30% decrease in the SOD of target lesions) according to RECIST 1.1 as assessed by BICR, DOR was defined as the time from the earliest date of qualifying response (CR or PR) until earliest date of progressive disease (PD, ≥20% increase in the SOD of target lesions) or death from any cause, whichever came first. DOR was censored at the last tumor assessment date if a responder did not have PD or death. |
| Secondary | DOR According to iRECIST Assessed by BICR | Up to ~36 months | For participants who demonstrated complete response (CR, disappearance of all target lesions) or partial response (PR, ≥30% decrease in the SOD of target lesions) according to iRECIST as assessed by BICR, DOR was defined as the time from the earliest date of qualifying response (CR or PR) until earliest date of progressive disease (PD, ≥20% increase in the SOD of target lesions) or death from any cause, whichever came first. DOR was censored at the last tumor assessment date if a responder did not have PD or death. iRECIST is a modification to RECIST that takes into account unique patterns of atypical response in immunotherapy and enables treatment beyond initial radiographic progression. |
| Secondary | Disease Control Rate (DCR) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | DCR was defined as the percentage of participants in the analysis population who have complete response (CR, disappearance of all target lesions), partial response (PR (≥30% decrease in the SOD of target lesions, taking as reference the baseline SOD), or stable disease (SD, neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD, ≥20% increase in the SOD of target lesions\]). Responses are according to RECIST 1.1 as assessed by BICR. |
| Secondary | DCR According to iRECIST 1.1 Assessed by BICR | Up to ~36 months | DCR was defined as the percentage of participants in the analysis population who have CR (disappearance of all target lesions), PR (≥30% decrease in the SOD of target lesions, taking as reference the baseline SOD), or stable disease (SD, neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD \[≥20% increase in the SOD of target lesions\]). Responses are according to iRECIST 1.1 as assessed by BICR. iRECIST is a modification to RECIST that takes into account unique patterns of atypical response in immunotherapy and enables treatment beyond initial radiographic progression. |
| Secondary | Time to Response (TTR) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | TTR was defined as the time from the date of enrollment day to the first date of confirmed CR (disappearance of all target lesions) or PR (≥30% decrease in the SOD of target lesions, taking as reference the baseline SOD). Responses are according to RECIST 1.1 as assessed by BICR. |
| Secondary | TTR According to iRECIST 1.1 Assessed by BICR | Up to ~36 months | TTR was defined as the time from the date of enrollment day to the first date of confirmed CR (disappearance of all target lesions) or PR (≥30% decrease in the SOD of target lesions, taking as reference the baseline SOD). Responses are according to iRECIST 1.1 as assessed by BICR. iRECIST is a modification to RECIST that takes into account unique patterns of atypical response in immunotherapy and enables treatment beyond initial radiographic progression. |
| Secondary | Progression-free Survival (PFS) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | PFS was defined as the time from the date of enrollment day to the first documented PD (defined as ≥20% increase in the SOD of target lesions) or death due to any cause, whichever occurred first. Responses are according to RECIST 1.1 as assessed by BICR. |
| Secondary | PFS According to iRECIST 1.1 Assessed by BICR | Up to ~36 months | PFS was defined as the time from the date of enrollment day to the first documented PD (defined as ≥20% increase in the SOD of target lesions) or death due to any cause, whichever occurred first. Responses are according to iRECIST 1.1 as assessed by BICR. iRECIST is a modification to RECIST that takes into account unique patterns of atypical response in immunotherapy and enables treatment beyond initial radiographic progression. |
1 to 10 of 13Source ClinicalTrials.gov
See all 13 registered outcomesOutcomes13
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Objective Response Rate (ORR) According to Response Evaluation Criteria In Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) | Up to ~36 months | All participants who received ≥1 dose of study treatment are included. | Percentage of participants | NUMBER |
| SECONDARY | ORR According to Immune-related Response Evaluation Criteria In Solid Tumors (iRECIST) Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | Percentage of participants | NUMBER |
| SECONDARY | Duration of Response (DOR) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug and had a confirmed response of CR or PR are included. | months | MEDIAN |
| SECONDARY | DOR According to iRECIST Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug and had a confirmed response of CR or PR are included. | months | MEDIAN |
| SECONDARY | Disease Control Rate (DCR) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | Percentage of participants | NUMBER |
| SECONDARY | DCR According to iRECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | Percentage of participants | NUMBER |
| SECONDARY | Time to Response (TTR) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | months | MEDIAN |
| SECONDARY | TTR According to iRECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | months | MEDIAN |
| SECONDARY | Progression-free Survival (PFS) According to RECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | months | MEDIAN |
| SECONDARY | PFS According to iRECIST 1.1 Assessed by BICR | Up to ~36 months | All participants who received ≥1 dose of study drug are included. | months | MEDIAN |
1 to 10 of 13Source ClinicalTrials.gov
See all 13 outcomesResults by group26
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Objective Response Rate (ORR) According to Response Evaluation Criteria In Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 72.2 | 95% Confidence Interval 58.4 to 83.5 | Percentage of participants | |
| Objective Response Rate (ORR) According to Response Evaluation Criteria In Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 80.4 | 95% Confidence Interval 66.1 to 90.6 | Percentage of participants | |
| ORR According to Immune-related Response Evaluation Criteria In Solid Tumors (iRECIST) Assessed by BICR | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 72.2 | 95% Confidence Interval 58.4 to 83.5 | Percentage of participants | |
| ORR According to Immune-related Response Evaluation Criteria In Solid Tumors (iRECIST) Assessed by BICR | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 80.4 | 95% Confidence Interval 66.1 to 90.6 | Percentage of participants | |
| Duration of Response (DOR) According to RECIST 1.1 Assessed by BICR | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 10.6 | 95% Confidence Interval 5.6 to NA | months | |
| Duration of Response (DOR) According to RECIST 1.1 Assessed by BICR | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 9.5 | 95% Confidence Interval 4.7 to 15.3 | months | |
| DOR According to iRECIST Assessed by BICR | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 10.6 | 95% Confidence Interval 5.6 to NA | months | |
| DOR According to iRECIST Assessed by BICR | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 9.5 | 95% Confidence Interval 4.7 to NA | months | |
| Disease Control Rate (DCR) According to RECIST 1.1 Assessed by BICR | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 96.3 | 95% Confidence Interval 87.3 to 99.5 | Percentage of participants | |
| Disease Control Rate (DCR) According to RECIST 1.1 Assessed by BICR | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 97.8 | 95% Confidence Interval 88.5 to 99.9 | Percentage of participants |
1 to 10 of 26Source ClinicalTrials.gov
See all 26 results by groupParticipant flow6
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 54 | |
| Overall Study | STARTED | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 46 | |
| Overall Study | COMPLETED | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 0 | |
| Overall Study | COMPLETED | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 0 | |
| Overall Study | NOT COMPLETED | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 54 | |
| Overall Study | NOT COMPLETED | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 46 |
Source ClinicalTrials.gov
Adverse events252
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 + Oxaliplatin +TS-1 (Cohort 1) | 13 | 54 | |
| other | Anaemia | Blood and lymphatic system disorders | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 18 | 46 | |
| other | Febrile neutropenia | Blood and lymphatic system disorders | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 4 | 54 | |
| other | Febrile neutropenia | Blood and lymphatic system disorders | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 1 | 46 | |
| other | Neutropenia | Blood and lymphatic system disorders | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 3 | 54 | |
| other | Neutropenia | Blood and lymphatic system disorders | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 6 | 46 | |
| other | Vertigo | Ear and labyrinth disorders | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 3 | 54 | |
| other | Vertigo | Ear and labyrinth disorders | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 0 | 46 | |
| other | Adrenal insufficiency | Endocrine disorders | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 3 | 54 | |
| other | Adrenal insufficiency | Endocrine disorders | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 3 | 46 |
1 to 10 of 252Source ClinicalTrials.gov
See all 252 adverse eventsAdverse event totals6
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 3 | 54 |
| Total, all-cause mortality | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 0 | 46 |
| Total, other adverse events | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 54 | 54 |
| Total, other adverse events | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 46 | 46 |
| Total, serious adverse events | Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) | 27 | 54 |
| Total, serious adverse events | Pembrolizumab + Cisplatin +TS-1 (Cohort 2) | 22 | 46 |
Source ClinicalTrials.gov
Papers1
The papers the trial lists on ClinicalTrials.gov.
| PMID | Listed as |
|---|---|
| 32145474 | DERIVED |
Source PubMed
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 comparisons4
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison | Source |
|---|---|
| Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) vs Pembrolizumab + Cisplatin +TS-1 (Cohort 2): Number of Participants With ≥1 Adverse Event (AE) | Trial comparisons |
| Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) vs Pembrolizumab + Cisplatin +TS-1 (Cohort 2): Number of Participants Discontinuing From Study Treatment Due to AE(s) | Trial comparisons |
| Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) vs Pembrolizumab + Cisplatin +TS-1 (Cohort 2): deaths from any cause | Trial comparisons |
| Pembrolizumab + Oxaliplatin +TS-1 (Cohort 1) vs Pembrolizumab + Cisplatin +TS-1 (Cohort 2): serious adverse events | 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.
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/NCT03382600
GET https://conductscience.org/api/trials/v1/NCT03382600/results?page=2