A Clinical Study of Boserolimab (MK-5890) With Pembrolizumab and Chemotherapy in People With Early Triple-Negative Breast Cancer (MK-5890-003)

February 17, 2026 updated by: Merck Sharp & Dohme LLC

A Phase 2, Umbrella Study to Evaluate the Safety, Tolerability, and Clinical Activity of Investigational Agents for Newly Diagnosed, High-Risk, Early-Stage Triple-Negative Breast Cancer

Researchers want to learn if giving boserolimab (MK-5890) with standard treatment (pembrolizumab and chemotherapy) before surgery can help treat triple negative breast cancer (TNBC). The goals of this study are to learn about the safety of boserolimab given with standard treatment before surgery and to learn if people tolerate it and how many people have no signs of cancer in the tissues and lymph nodes removed during surgery.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Withdrawn

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The umbrella design of this study provides the framework to evaluate the safety, tolerability and clinical activity of different investigational agents in participants with newly diagnosed, high-risk, early-stage TNBC who might benefit from adding these investigational agents to pembrolizumab plus chemotherapy.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Taiwan
      • Tainan, Taiwan, 704
        • National Cheng Kung University Hospital ( Site 0901)
  • United States
    • Nevada
      • Las Vegas, Nevada, United States, 89102
        • Optum Care Cancer Center ( Site 0004)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

  • Has previously untreated high-risk, early-stage, non-metastatic (M0) breast cancer (BC), defined as tumor stage T1c, nodal stage N1-2, or tumor stage T2-4, nodal stage N0-2
  • Has provided a core needle biopsy for tissue diagnosis of the current breast cancer less than 29 days prior to the date of informed consent
  • Has centrally confirmed diagnosis of BC that is triple-negative based on the American Society of Clinical Oncology/College of American Pathologists guidelines
  • Has Eastern Cooperative Oncology Group performance status of 0 or 1 performed within 28 days before treatment randomization
  • Has left ventricle ejection fraction of ≥50% as assessed by echocardiogram or multigated acquisition scan performed at screening
  • Has a history of exposure to anthracycline; participants can be eligible after completion of a Sponsor consultation form, if cumulative lifetime doses are as follows: Doxorubicin <100 mg/m2, Epirubicin <180 mg/m2, Mitoxantrone <40 mg/m2, Idarubicin <22.5 mg/m2. Note: If another anthracycline or more than one anthracycline has been used, the cumulative dose must not exceed the equivalent of 100 mg/m2 of doxorubicin

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

  • Has documented Grade ≥2 peripheral neuropathy
  • Has uncontrolled or significant cardiovascular disease
  • Has received prior therapy with an anti-programmed cell death protein 1 (anti-PD-1), anti-programmed cell death-ligand 1 (anti-PD-L1), or anti-PD-L2 agent, or with an agent directed to another stimulatory or coinhibitory T-cell receptor (e.g., cytotoxic T-lymphocyte-associated protein-4 [CTLA-4], OX-40 [cluster of differentiation (CD) 134], or CD137)
  • Has received any prior treatment, including radiation, systemic therapy, and/or definitive surgery for currently diagnosed breast cancer
  • Has received prior systemic anticancer therapy
  • Has undergone excisional biopsy of the primary tumor and/or axillary lymph node dissection prior to study treatment
  • Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of study intervention
  • Has a known additional malignancy that is progressing or has required active treatment within the past 5 years
  • Has active autoimmune disease that has required systemic treatment in the past 2 years with need for disease modifying agents such as corticosteroids or immunosuppressive drugs
  • Has history of (noninfectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease
  • Has an active infection requiring systemic therapy
  • HIV-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease
  • Has severe hypersensitivity (Grade ≥3) to pembrolizumab, any investigational agent or study intervention, any of its excipients, and/or to another biologic therapy
  • Has a history of allogeneic tissue/solid organ transplant

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Pembrolizumab+ Paclitaxel+ Carboplatin
Participants will receive pembrolizumab PLUS paclitaxel PLUS carboplatin followed by pembrolizumab PLUS doxorubicin hydrochloride or epirubicin hydrochloride and cyclophosphamide as neoadjuvant therapy prior to surgery. In adjuvant therapy participants will receive pembrolizumab PLUS optional additional adjuvant treatment of physician's choice (TPC), capecitabine or olaparib.
Biological: Pembrolizumab
Neoadjuvant therapy - 200 mg intravenous (IV) infusion every 3 weeks (Q3W) for up to approximately 24 weeks Adjuvant therapy - 200 mg IV infusion Q3W or 400 mg IV infusion every 6 weeks (Q6W) for up to approximately 30 weeks.
Other Names:
  • MK-3475
  • SCH 900475
  • Keytruda®
Drug: Paclitaxel
80 mg/m^2 by IV infusion every week for up to 12 weeks.
Drug: Carboplatin
AUC 1.5 mg/mL/min by IV infusion every week for up to 12 weeks.
Drug: Doxorubicin (hydrochloride)
60 mg/m^2 by IV infusion Q3W for up to 12 weeks.
Drug: Epirubicin Hydrochloride
90 mg/m^2 by IV infusion every 3 weeks (Q3W) for up to 12 weeks.
Drug: Cyclophosphamide
600 mg/m^2 by IV infusion every 3 weeks (Q3W) for up to 12 weeks.
Drug: Capecitabine
1000 mg/m^2 to 1250 mg/m^2 by oral administration twice a day (2 weeks on and 1 week off) for up to approximately 24 weeks.
Drug: Olaparib (if approved/available locally)
300 mg by oral administration twice a day for up to approximately 52 weeks.
Experimental: Pembrolizumab+Boserolimab+Paclitaxel+ Carboplatin
Participants will receive pembrolizumab PLUS boserolimab PLUS paclitaxel PLUS carboplatin followed by pembrolizumab PLUS doxorubicin hydrochloride or epirubicin hydrochloride and cyclophosphamide PLUS boserolimab as neoadjuvant therapy prior to surgery. In adjuvant therapy participants will receive pembrolizumab PLUS optional additional adjuvant treatment of physician's choice (TPC), capecitabine or olaparib.
Biological: Pembrolizumab
Neoadjuvant therapy - 200 mg intravenous (IV) infusion every 3 weeks (Q3W) for up to approximately 24 weeks Adjuvant therapy - 200 mg IV infusion Q3W or 400 mg IV infusion every 6 weeks (Q6W) for up to approximately 30 weeks.
Other Names:
  • MK-3475
  • SCH 900475
  • Keytruda®
Drug: Paclitaxel
80 mg/m^2 by IV infusion every week for up to 12 weeks.
Drug: Carboplatin
AUC 1.5 mg/mL/min by IV infusion every week for up to 12 weeks.
Drug: Doxorubicin (hydrochloride)
60 mg/m^2 by IV infusion Q3W for up to 12 weeks.
Drug: Epirubicin Hydrochloride
90 mg/m^2 by IV infusion every 3 weeks (Q3W) for up to 12 weeks.
Drug: Cyclophosphamide
600 mg/m^2 by IV infusion every 3 weeks (Q3W) for up to 12 weeks.
Drug: Capecitabine
1000 mg/m^2 to 1250 mg/m^2 by oral administration twice a day (2 weeks on and 1 week off) for up to approximately 24 weeks.
Drug: Olaparib (if approved/available locally)
300 mg by oral administration twice a day for up to approximately 52 weeks.
Biological: Boserolimab
30 mg by IV infusion every 6 weeks (Q6W) for up to 12 Weeks.
Other Names:
  • MK-5890

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of participants with one or more adverse events (AEs)
Time Frame: Up to approximately 34 months
An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.
Up to approximately 34 months
Number of participants who discontinue study intervention due to an AE
Time Frame: Up to approximately 27 months
An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.
Up to approximately 27 months
Pathological complete response (pCR) rate at the time of definitive surgery
Time Frame: Up to approximately 9 months
pCR (ypT0/Tis ypN0) is defined as the absence of residual invasive cancer on hematoxylin and eosin evaluation of the complete resected breast specimen and all sampled regional lymph nodes after completion of neoadjuvant systemic therapy per current American Joint Committee on Cancer (AJCC) staging criteria assessed by the local pathologist at the time of definitive surgery.
Up to approximately 9 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
pCR-no ductal carcinoma in situ (DCIS) rate at the time of definitive surgery
Time Frame: Up to approximately 9 months
pCR-no ductal carcinoma in situ (DCIS) (ypT0 ypN0) is defined as the absence of residual invasive and in situ cancer on hematoxylin and eosin evaluation of the complete resected breast specimen and all sampled regional lymph nodes after completion of neoadjuvant systemic therapy per current AJCC staging criteria assessed by the local pathologist at the time of definitive surgery.
Up to approximately 9 months
Event-Free Survival (EFS)
Time Frame: Up to approximately 72 months
EFS is defined as the time from randomization to disease progression that precludes surgery, local or distant recurrence, or death due to any cause, whichever occurs first.
Up to approximately 72 months
Overall Survival (OS)
Time Frame: Up to approximately 72 months
OS is defined as the time from randomization to death due to any cause.
Up to approximately 72 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Merck Sharp & Dohme LLC

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 26, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 18, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 18, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 11, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 11, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 17, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 5890-003
  • MK-5890-003 (Other Identifier: MSD)
  • U1111-1312-3982 (Registry Identifier: UTN)
  • 2024-517505-87-00 (Registry Identifier: EU CT)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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