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

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• Status: Withdrawn
• Conditions: Early Triple Negative Breast Cancer
• Intervention / Treatment: Biological: Pembrolizumab; Drug: Paclitaxel; Drug: Carboplatin; Drug: Doxorubicin (hydrochloride); Drug: Epirubicin Hydrochloride; Drug: Cyclophosphamide; Drug: Capecitabine; Drug: Olaparib (if approved/available locally); Biological: Boserolimab

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: Interventional
• Phase: Phase 2

Contacts and Locations

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

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Number of participants with one or more adverse events (AEs)	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	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	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

Outcome Measure	Measure Description	Time Frame
pCR-no ductal carcinoma in situ (DCIS) rate at the time of definitive surgery	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)	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)	OS is defined as the time from randomization to death due to any cause.	Up to approximately 72 months

Collaborators and Investigators

• Sponsor: Merck Sharp & Dohme LLC
• Investigators: Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

Helpful Links

• Merck Clinical Trials Information
• Plain Language Summary

Study record dates

Study Major Dates

• Study Start (Estimated): March 26, 2025
• Primary Completion (Estimated): January 18, 2029
• Study Completion (Estimated): March 18, 2031

Study Registration Dates

• First Submitted: February 11, 2025
• First Submitted That Met QC Criteria: February 11, 2025
• First Posted (Actual): February 17, 2025

Study Record Updates

• Last Update Posted (Actual): February 19, 2026
• Last Update Submitted That Met QC Criteria: February 17, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Breast cancer; Pembrolizumab; Neoadjuvant; Triple Negative Breast Cancer; Umbrella study; Boserolimab
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms; Triple Negative Breast Neoplasms; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Nucleic Acids, Nucleotides, and Nucleosides; Hydrocarbons; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Carbohydrates; Polycyclic Aromatic Hydrocarbons; Hydrocarbons, Aromatic; Polycyclic Compounds; Glycosides; Coordination Complexes; Taxoids; Cyclodecanes; Diterpenes; Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Phosphoramide Mustards; Nitrogen Mustard Compounds; Mustard Compounds; Hydrocarbons, Halogenated; Phosphoramides; Organophosphorus Compounds; Nucleosides; Uracil; Pyrimidinones; Anthracyclines; Naphthacenes; Aminoglycosides; Daunorubicin; Deoxyribonucleosides; Fluorouracil; Capecitabine; Cyclophosphamide; Carboplatin; Doxorubicin; Paclitaxel; Epirubicin; pembrolizumab; olaparib
• Other Study ID 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