18 and older, any sex, with Breast Cancer. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) by Central Imaging Vendor (CIV) in All Cohort A ParticipantsPrimary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
ORR was defined as the percentage of participants who had a Complete Response (CR: disappearance of all target lesions) or a Partial Response (PR: ≥30% decrease in sum of diameters \[SOD\] of target lesions) per RECIST 1.1 by CIV. ORR was estimated by Agresti-Coull (A-C) method. The percentage of participants who had CR or PR is reported here as the protocol-specified ORR, for the first pembrolizumab course, assessed from enrolment/treatment initiation and analyzed by Cohort, for all participants in Cohort A. Per protocol final ORR analysis in all Cohort A participants was done at the time of
Group
Value
95% CI
Cohort A: Pembrolizumab
5.3
2.7 – 9.9
ORR Per RECIST 1.1 by CIV in Subgroup of Cohort A Participants With Programmed Cell Death- Ligand 1 (PD-L1) Positive Tumor ExpressionPrimary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
ORR was defined as the percentage of participants who had a CR (disappearance of all target lesions) or a PR (≥30% decrease in SOD of target lesions) per RECIST 1.1 by CIV. ORR was estimated by A-C method. The percentage of participants who had CR or PR is reported here as the protocol-specified ORR, for the first pembrolizumab course, assessed from enrolment/treatment initiation and analyzed by Cohort for the subgroup of Cohort A participants with tumor immunohistochemistry (IHC) defined-PD-L1 positive expression (PD-L1+). Per protocol final ORR analysis in the Cohort A PD-L1+ subgroup was do
Group
Value
95% CI
Cohort A: Pembrolizumab
5.7
2.4 – 12.2
Number of Participants Who Experienced at Least One Adverse Event (AE)Primary· Up to ~31 months
An AE was defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom or disease temporally associated with the use of a medicinal product or protocol-specified procedure. Any worsening of a pre-existing condition that is temporally associated with the use of the Sponsor's product is also an AE. Per protocol the number of participants who experienced at least one AE, for the first
Group
Value
95% CI
Cohort A: Pembrolizumab
161
Cohort B: Pembrolizumab
83
Number of Participants Who Discontinued Study Drug Due to an AEPrimary· Up to ~31 months
An AE was defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom or disease temporally associated with the use of a medicinal product or protocol-specified procedure. Any worsening of a pre-existing condition that is temporally associated with the use of the Sponsor's product is also an AE. Per protocol the number of participants who discontinued study drug due to an AE, in th
Group
Value
95% CI
Cohort A: Pembrolizumab
8
Cohort B: Pembrolizumab
3
ORR Per RECIST 1.1 by CIV in All Cohort B ParticipantsSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
ORR was defined as the percentage of participants who had a CR (disappearance of all target lesions) or a PR (≥30% decrease in SOD of target lesions) per RECIST 1.1 by CIV. ORR was estimated by A-C method. The percentage of participants who had CR or PR is reported here as the protocol-specified ORR, for the first pembrolizumab course, assessed from enrolment/treatment initiation and analyzed by Cohort for all participants in Cohort B. Per protocol final ORR analysis in all Cohort B participants was done at the time of final statistical efficacy analysis, with a 10-Nov-2017 cutoff. Per protoco
Group
Value
95% CI
Cohort B: Pembrolizumab
21.4
13.9 – 31.4
Duration of Response (DOR) Per RECIST 1.1 by CIV in All Cohort A and Cohort B ParticipantsSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
For participants who had CR (disappearance of all target lesions) or PR (≥30% target lesion SOD decrease) per RECIST 1.1 by CIV, DOR was defined as time from first documented CR or PR until progressive disease (PD: ≥20% target lesion SOD increase, ≥5 mm absolute SOD increase; PD is also ≥1 new lesion appearance) or death. DOR for those who didn't progress/die at time of analysis was censored at last tumor assessment. Per protocol DOR for the first pembrolizumab course, assessed from enrolment/treatment initiation, estimated by Kaplan-Meier (KM) method and analyzed by cohort is reported here fo
Group
Value
95% CI
Cohort A: Pembrolizumab
NA
NA – NA
Cohort B: Pembrolizumab
10.4
4.2 – NA
DOR Per RECIST 1.1 by CIV in Subgroup of Cohort A Participants With PD-L1 Positive Tumor ExpressionSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
For participants who had CR (disappearance of all target lesions) or PR (≥30% target lesion SOD decrease) per RECIST 1.1 by CIV, DOR was defined as time from first documented CR or PR until PD (≥20% target lesion SOD increase, ≥5 mm absolute SOD increase; PD is also ≥1 new lesion appearance) or death. DOR for those who didn't progress/die at time of analysis was censored at last tumor assessment. Per protocol DOR for first pembrolizumab course, assessed from enrolment/treatment initiation, estimated by KM method and analyzed by Cohort is reported here for subgroup of Cohort A participants with
Group
Value
95% CI
Cohort A: Pembrolizumab
NA
6.3 – NA
Disease Control Rate (DCR) Per RECIST 1.1 by CIV in All Cohort A and Cohort B ParticipantsSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
DCR was defined as the percentage of participants in the analysis population who have CR (disappearance of all target lesions) or PR (≥30% target lesion SOD decrease) or SD (not sufficient shrinkage for PR or sufficient increase for PD \[≥20% target lesion SOD increase, ≥5 mm absolute SOD increase; PD is also ≥1 new lesion appearance\]) for ≥24 weeks per RECIST 1.1 by CIV. Per protocol percentage of participants who had CR, PR or SD per RECIST 1.1 by CIV is reported here as DCR, for the first pembrolizumab course, assessed from enrolment/treatment initiation, estimated by A-C method and analyz
Group
Value
95% CI
Cohort A: Pembrolizumab
7.6
4.4 – 12.7
Cohort B: Pembrolizumab
23.8
15.9 – 34.0
DCR Per RECIST 1.1 by CIV in Subgroup of Cohort A Participants With PD-L1 Positive Tumor ExpressionSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
DCR was defined as the percentage of participants who have CR (disappearance of all target lesions) or PR (≥30% target lesion SOD decrease) or SD (not sufficient shrinkage for PR or sufficient increase for PD \[≥20% target lesion SOD increase, ≥5 mm absolute SOD increase; PD is also ≥1 new lesion appearance\]) for ≥24 weeks per RECIST 1.1 by CIV. Per protocol percentage of participants who had CR, PR or SD per RECIST 1.1 by CIV is reported here as DCR for the first pembrolizumab course, assessed from enrolment/treatment initiation, estimated by A-C method and analyzed by Cohort for subgroup of
Group
Value
95% CI
Cohort A: Pembrolizumab
9.5
5.1 – 16.8
Progression Free Survival (PFS) Per RECIST 1.1 by CIV in All Cohort A and Cohort B ParticipantsSecondary· Up to ~28 months (through pre-specified final statistical analysis cut-off date of 10-Nov-2017)
PFS was defined as the time from first dose of study drug to the first documented PD per RECIST 1.1 by CIV, or death due to any cause, whichever occurred first. Per RECIST 1.1 PD was defined as ≥20% increase in SOD of target lesions and absolute SOD increase of ≥5 mm. Appearance of ≥1 new lesion is also PD. PFS was estimated by KM method. Per protocol PFS, for the first pembrolizumab course, assessed from enrolment/treatment initiation and analyzed by Cohort is reported here for all participants in Cohort A and Cohort B. Per protocol final PFS analysis in all Cohort A and Cohort B participants
Group
Value
95% CI
Cohort A: Pembrolizumab
2.0
1.9 – 2.0
Cohort B: Pembrolizumab
2.1
2.0 – 2.2
PFS Per RECIST 1.1 by CIV in Subgroup of Cohort A Participants With PD-L1 Positive Tumor ExpressionSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
PFS was defined as the time from first dose of study drug to the first documented PD per RECIST 1.1 by CIV, or death due to any cause, whichever occurred first. Per RECIST 1.1 PD was defined as ≥20% increase in SOD of target lesions and absolute SOD increase of ≥5 mm. Appearance of ≥1 new lesion is also PD. PFS was estimated by KM method. Per protocol PFS, for the first pembrolizumab course, assessed from enrolment/treatment initiation and analyzed by Cohort is reported here for the subgroup of Cohort A participants with tumor IHC defined-PD-L1 positive expression (PD-L1+). Per protocol final
Group
Value
95% CI
Cohort A: Pembrolizumab
2.0
1.9 – 2.1
Overall Survival (OS) in All Cohort A and Cohort B ParticipantsSecondary· Up to ~28 months (through pre-specified statistical analysis cut-off date of 10-Nov-2017)
OS was defined as the time from the first dose of study drug to death due to any cause. OS was estimated by KM method. Per protocol OS, for the first pembrolizumab course, assessed from enrolment/treatment initiation and analyzed by Cohort is reported here for all participants in Cohort A and Cohort B. Per protocol final OS analysis in all Cohort A and Cohort B participants was done at the time of final statistical efficacy analysis with a 10-Nov-2017 cutoff.
Group
Value
95% CI
Cohort A: Pembrolizumab
9.0
7.6 – 11.2
Cohort B: Pembrolizumab
18.0
12.9 – 23.0
Adverse events — posted to ClinicalTrials.gov
Time frame: Safety: Up to ~31 months for pembrolizumab first course and up to additional ~15 months for pembrolizumab second course (AEs were collected through 90 days post treatment for SAEs and 30 days post treatment for NSAEs); All-cause mortality (ACM): Up to ~54 months for pembrolizumab first and second course.
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
This is a two-part study of pembrolizumab monotherapy in participants with metastatic triple-negative breast cancer (mTNBC). Part 1 of the study will examine the efficacy and safety of pembrolizumab monotherapy as first line or above treatment in participants who have received either no prior systemic treatment or at least one prior systemic treatment for metastatic breast cancer. Part 2 of the study, if done, will expand the investigation of pembrolizumab treatment in a subgroup of participants from Part 1 and will only start after enrollment in Part 1 has been completed. There will be no hypothesis testing in this study.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT07572123 — Evaluating the Addition of Maintenance Immunotherapy Compared to the Usual Treatment of Chemotherapy and Autologous Stem
· Phase 2, PHASE3
· not yet recruiting
NCT07275216 — Pembrolizumab in Combination With Chemotherapy for the Treatment of Frail Hodgkin Lymphoma Patients Ineligible for Stand
· Phase 2
· not yet recruiting
NCT07302347 — A Study of Pembrolizumab in Japanese Pediatric Participants With Solid Tumors or Lymphomas and Japanese Adult Participan
· Phase 1, PHASE2
· recruiting
NCT06724042 — Study of ISM5939 in Patients With Advanced and/or Metastatic Solid Tumors
· Phase 1
· not yet recruiting
NCT07383441 — Adding Biotherapy or Placebo to Standard Treatment for Advanced Kidney Cancer
· Phase 3
· not yet recruiting
Other recruiting trials for Breast Cancer
Currently open trials in the same condition.
NCT06148038 — CBD for Breast Cancer Primary Tumors
· Phase 1
· recruiting
NCT07405801 — A Phase II Study Evaluating the Efficacy and Safety of Inavolisib Plus Ribociclib Plus Fulvestrant Versus Placebo Plus R
· Phase 2
· recruiting
NCT07285993 — Detection and Outcomes in Metastatic Invasive Lobular Breast Cancer Through Novel F-18 FAP PET
· Phase 2
· recruiting
NCT07510698 — Same-Day Awake Mastectomy With Immediate Breast Reconstruction for Patients With Breast Cancer
· NA
· recruiting
NCT06768931 — Biolosion Combined Standard Neoadjuvant Therapy to Treat Triple-negative Breast Cancer
· Phase 2
· recruiting
Other Merck Sharp & Dohme LLC trials
Trials by the same sponsor.
NCT07224477 — A Clinical Study of V540A in Healthy Female Participants (V540A-005)
· Phase 2
· not yet recruiting
NCT07302347 — A Study of Pembrolizumab in Japanese Pediatric Participants With Solid Tumors or Lymphomas and Japanese Adult Participan
· Phase 1, PHASE2
· recruiting
NCT07528508 — A Clinical Trial in Healthy Participants to Study the Effect of a Single Dose of MK-8527 on Levels of Methadone (MK-8527
· Phase 1
· not yet recruiting
NCT07513376 — A Clinical Trial of Adjuvant Intismeran (V940) With or Without Pembrolizumab Coformulated With Berahyaluronidase Alfa (M
· Phase 3
· not yet recruiting
NCT07532304 — A Clinical Trial of MK-4646 With Bictegravir/Emtricitabine/Tenofovir Alafenamide and Dolutegravir in Healthy Adult Parti
· Phase 1
· not yet recruiting
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Merck Sharp & Dohme LLC
Last refreshed: 16 December 2020
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT02447003.