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AzTrials

Breast NeoplasmsPhase 2NCT06797635

Study of Patritumab Deruxtecan Plus Pembrolizumab With Other Anticancer Agents in Participants With High-Risk Early-Stage Triple-Negative or Hormone Receptor-Low Positive/HER-2 Negative Breast Cancer (MK-1022-010, HERTHENA-Breast-03)

A Phase 2 study testing Patritumab deruxtecan, Pembrolizumab and Paclitaxel in people with Breast Neoplasms and Breast Cancer, run by Merck Sharp & Dohme LLC at 17 sites in 4 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

Researchers are looking for new ways to treat triple-negative breast cancer (TNBC) and hormone receptor (HR) low positive/human epidermal growth factor receptor-2 (HER2) negative breast cancer. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Breast Neoplasms, Breast Cancer
What is being tested?
Patritumab deruxtecan, Pembrolizumab and Paclitaxel
Could I receive a placebo?
No, everyone receives an active treatment
How many people
372 participants
Where
17 sitesin 4 countries
Study dates
20 Mar 2025to 16 Mar 2031
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • The main inclusion criteria include but are not limited to the following:
  • Has locally advanced, non-metastatic (M0), breast cancer, defined as any of the following combined primary tumor (T) and regional lymph node (N) staging per current American Joint Committee on Cancer (AJCC) criteria: cT1c, N1-N2; cT2, N0-N2; cT3, N0-N2; or cT4a-d, N0-N2
  • Has centrally confirmed diagnosis of breast cancer that is triple-negative or HR-low+/HER2- breast cancer that will be treated according to the triple-negative breast cancer (TNBC) paradigm
  • Participants who are Hepatitis B surface antigen (HBsAg) positive are eligible if they have received Hepatitis B virus (HBV) antiviral therapy for at least 4 weeks and have undetectable HBV viral load
  • Participants with a history of Hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable
  • Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 within 28 days prior to allocation/randomization
  • Has left ventricular ejection fraction (LVEF) of ≥50% or ≥ lower limit of normal (LLN) as assessed by echocardiogram (ECHO) or multigate acquisition scan (MUGA) scan

Who cannot join

  • The main exclusion criteria include but are not limited to the following:
  • Has uncontrolled or significant cardiovascular disease before randomization
  • Has any history of or evidence of any current leptomeningeal carcinomatosis.
  • Has clinically significant corneal disease
  • Has human immunodeficiency virus (HIV) infection with a history of Kaposi sarcoma and/or multicentric Castleman disease
  • Has evidence of ongoing, uncontrolled, systemic bacterial, fungal, or viral infection
Show all 16Show fewer
  • Has received prior therapy with an anti-programmed death (PD)-1, anti-PD-L1, or anti-PD-L2 agent, or with an agent directed to another stimulatory or coinhibitory T-cell receptor
  • Has received any prior treatment, including radiation, systemic therapy, and/or definitive surgery for currently diagnosed breast cancer
  • Has received prior treatment with an anti-human epidermal growth factor receptor 3 (HER3) antibody and/or antibody-drug conjugate (ADC) that consists of an exatecan derivative that is a topoisomerase I inhibitor (e.g., trastuzumab deruxtecan)
  • Has metastatic (Stage IV) breast cancer or cN3 nodal involvement
  • Has known additional malignancy that is progressing or has required active treatment within the past 5 years
  • Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis
  • Has any history of interstitial lung disease (ILD)/pneumonitis irrespective of steroid use, or current or suspected ILD
  • Has an active infection requiring systemic therapy
  • Has concurrent active HBV and HCV infection
  • Has clinically severe respiratory compromise resulting from intercurrent pulmonary illness

Trial locations and contacts

17 sites in 4 countries. Contact the study team or a site near you to ask about taking part.

Toll Free Number contact

1-888-577-8839

Trialsites@msd.com

17 sites in 4 countries

United States8 sites, 8 recruiting

  • Intermountain Health St. Vincent Regional Hospital - Cancer Centers of Montana ( Site 0003)

    Billings, Montana, 59102

    Study Coordinator, 406-238-6685

    Recruiting

  • Texas Oncology - DFW ( Site 8000)

    Dallas, Texas, 75246

    Study Coordinator, 214-370-1067

    Recruiting

  • Houston Methodist Hospital ( Site 0022)

    Houston, Texas, 77030

    Study Coordinator, 713-441-9948

    Recruiting

  • SCRI Oncology Partners ( Site 7000)

    Nashville, Tennessee, 37203

    Study Coordinator, 844-482-4812

    Recruiting

  • Virginia Oncology Associates (VOA) ( Site 8001)

    Norfolk, Virginia, 23502

    Study Coordinator, 844-482-4812

    Recruiting

  • UCLA Hematology/Oncology - Parkside ( Site 0021)

    Santa Monica, California, 90404

    Study Coordinator, 424-402-9520

    Recruiting

  • Orchard Healthcare Research Inc. ( Site 0006)

    Skokie, Illinois, 60077

    Study Coordinator, 847-568-9932

    Recruiting

  • Northwest Cancer Specialists (Compass Oncology) ( Site 8003)

    Tigard, Oregon, 97223

    Study Coordinator, 360-944-9889

    Recruiting

Other trials in United States

South Korea3 sites, 3 recruiting

  • Seoul National University Hospital ( Site 2400)

    Seoul, 03080

    Study Coordinator, +82220720850

    Recruiting

  • Severance Hospital, Yonsei University Health System ( Site 2402)

    Seoul, 03722

    Study Coordinator, +82222288135

    Recruiting

  • Asan Medical Center ( Site 2401)

    Seoul, 05505

    Study Coordinator, +82230103217

    Recruiting

Other trials in South Korea

Spain3 sites, 3 recruiting

  • Institut Català d'Oncologia (ICO) - Badalona ( Site 1700)

    Badalona, Catalonia, 08916

    Study Coordinator, +34934978925

    Recruiting

  • Hospital Universitario Reina Sofia ( Site 1702)

    Córdoba, 14004

    Study Coordinator, +34 957012408

    Recruiting

  • Clinica Universidad de Navarra ( Site 1703)

    Madrid, Madrid, Comunidad de, 28027

    Study Coordinator, +34913531920

    Recruiting

Other trials in Spain

Taiwan3 sites, 3 recruiting

  • Taichung Veterans General Hospital ( Site 2502)

    Taichung, 407

    Study Coordinator, +886423592525

    Recruiting

  • National Cheng Kung University Hospital ( Site 2503)

    Tainan, 704

    Study Coordinator, +88662353535

    Recruiting

  • Koo Foundation Sun Yat-Sen Cancer Center ( Site 2501)

    Taipei, 112

    Study Coordinator, 886228970011x1686

    Recruiting

Other trials in Taiwan

About this study

Official title: An Open-label Randomized Phase 2 Study to Evaluate Safety and Efficacy of Patritumab Deruxtecan Plus Pembrolizumab Administered Either Before or After Carboplatin/Paclitaxel Plus Pembrolizumab Compared With Pembrolizumab in Combination With Chemotherapy Followed by Surgery and Adjuvant Pembrolizumab for High-Risk Early-Stage Triple-Negative or Hormone Receptor-Low Positive/Human Epidermal Growth Factor Receptor-2 Negative Breast Cancer (HERTHENA-Breast03)

Researchers are looking for new ways to treat triple-negative breast cancer (TNBC) and hormone receptor (HR) low positive/human epidermal growth factor receptor-2 (HER2) negative breast cancer. The main goals of this study are to learn:

  • About the safety of the study treatments and if people tolerate them
  • If people who receive patritumab deruxtecan, pembrolizumab, and chemotherapy before surgery have fewer cancer cells removed during surgery compared to those who receive only pembrolizumab (pembro) and chemotherapy.
Being tested
Patritumab deruxtecan, Pembrolizumab, Paclitaxel, Carboplatin, Doxorubicin hydrochloride
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Patritumab deruxtecanBiological

    Also called MK-1022, HER3-DXd, U3-1402

    Administered via IV infusion as neoadjuvant treatment

  • PembrolizumabBiological

    Also called MK-3475, KEYTRUDA®

    Administered via IV infusion as neoadjuvant treatment in Part 1 and via IV infusion as neoadjuvant and adjuvant treatment in Part 2

  • PaclitaxelDrug

    Also called TAXOL®, ONXAL®

    Administered via IV infusion as neoadjuvant treatment

  • CarboplatinDrug

    Also called PARAPLATIN®

    Administered via IV infusion as neoadjuvant treatment

  • Doxorubicin hydrochlorideDrug

    Also called ADRIAMYCIN®

    Administered via IV infusion as neoadjuvant treatment in Arm C and an option for adjuvant treatment for participants with residual disease in Arms A and B in Part 2

  • Epirubicin hydrochlorideDrug

    Also called ELLENCE®

    Administered via IV infusion as neoadjuvant treatment in Arm C and an option for adjuvant treatment for participants with residual disease in Arms A and B in Part 2

  • CyclophosphamideDrug

    Also called CYTOXAN®

    Administered via IV infusion as neoadjuvant treatment in Arm C and an option for adjuvant treatment for participants with residual disease in Arms A and B in Part 2

  • CapecitabineDrug

    Also called XELODA®

    Administered via oral tablets as an option for adjuvant treatment for participants with residual disease in Part 2

  • OlaparibDrug

    Also called LYNPARZA®

    Administered via oral tablets as an option for adjuvant treatment for participants with germline BRCA mutations and residual disease in Part 2

Study groups in NCT06797635
Study groupRoleWhat they receive
Part 1, A: Pembrolizimab + patritumab deruxtecan → Pembrolizumab + paclitaxel + carboplatinExperimentalIn Part 1, participants receive neoadjuvant pembrolizumab 200 mg via intravenous (IV) infusion every 3 weeks (Q3W) plus patritumab deruxtecan via IV infusion Q3W for 12 weeks, followed by pembrolizumab 200 mg via IV infusion Q3W plus paclitaxel 80 mg/m^2 via IV infusion every week (QW) and carboplatin AUC1.5 mg/ml/min via IV infusion QW for 12 weeks. At 3 to 6 weeks after last dose of neoadjuvant treatment, participants will undergo surgery for their breast cancer.
Receives: Biological: Patritumab deruxtecan; Biological: Pembrolizumab; Drug: Paclitaxel; Drug: Carboplatin
Part 2, A: Pembrolizimab + patritumab deruxtecan → Pembrolizumab + paclitaxel + carboplatinExperimentalIn Part 2, participants receive neoadjuvant pembrolizumab 200 mg IV infusion every Q3W plus patritumab deruxtecan (dose to be determined in part 1) IV infusion Q3W for 12 weeks, followed by pembrolizumab 200 mg IV infusion Q3W plus paclitaxel 80 mg/m^2 IV infusion QW and carboplatin AUC1.5 mg/ml/min IV infusion QW for 12 weeks. At 3-6 weeks after last dose of neoadjuvant treatment, participants undergo surgery for breast cancer. After surgery, participants receive adjuvant pembrolizumab 400 mg IV every 6 weeks (Q6W) for ~30 weeks. Additional adjuvant treatment of physician's choice (TPC) may be given to participants with residual disease. TPC options are olaparib 300 mg oral twice daily (BID) for 1 year (participants with germline BRCA mutation [gBRCAm] only), capecitabine 1000-1250 mg/m^2 oral BID days 1-14 and 22-35 Q6W for 4 six-week cycles or doxorubicin 60mg/m^2 (or epirubicin 90 mg/m^2) IV Q3W or every 2 weeks (Q2W) and cyclophosphamide 600 mg/m^2 IV Q3W or Q2W for 4 doses.
Receives: Biological: Patritumab deruxtecan; Biological: Pembrolizumab; Drug: Paclitaxel; Drug: Carboplatin; Drug: Doxorubicin hydrochloride; Drug: Epirubicin hydrochloride; Drug: Cyclophosphamide; Drug: Capecitabine; Drug: Olaparib
Part 2, B: Pembrolizumab + paclitaxel + carboplatin → Pembrolizumab + patritumab deruxtecanExperimentalIn Part 2, participants receive neoadjuvant pembrolizumab 200 mg IV infusion Q3W plus paclitaxel 80 mg/m^2 IV infusion QW and carboplatin AUC1.5 mg/ml/min IV infusion QW for 12 weeks, followed by pembrolizumab 200 mg IV infusion Q3W plus patritumab deruxtecan (dose to be determined in part 1) via IV infusion Q3W for 12 weeks. At 3 to 6 weeks after last dose of neoadjuvant treatment, participants will undergo surgery for their breast cancer. After surgery, participants will receive adjuvant pembrolizumab 400 mg IV infusion Q6W for ~30 weeks. Additional adjuvant TPC may be administered to participants with residual disease. TPC options include olaparib 300 mg oral BID for 1 year (participants with gBRCAm only), capecitabine 1000-1250 mg/m^2 oral BID days 1-14 and 22-35 Q6W for 4 six-week cycles or doxorubicin 60mg/m^2 (or epirubicin 90 mg/m^2) IV infusion Q3W or Q2W and cyclophosphamide 600 mg/m^2 IV infusion Q3W or Q2W for 4 doses.
Receives: Biological: Patritumab deruxtecan; Biological: Pembrolizumab; Drug: Paclitaxel; Drug: Carboplatin; Drug: Doxorubicin hydrochloride; Drug: Epirubicin hydrochloride; Drug: Cyclophosphamide; Drug: Capecitabine; Drug: Olaparib
Part 2, C: Pembro + paclitaxel + carboplatin→ Pembro + doxorubicin (or epirubicin) +cyclophosphamideActive comparatorIn Part 2, participants receive neoadjuvant pembrolizumab 200 mg IV infusion Q3W plus paclitaxel 80 mg/m^2 IV infusion QW and carboplatin AUC1.5 mg/ml/min via IV infusion QW for 12 weeks, followed by pembrolizumab 200 mg IV infusion Q3W plus doxorubicin 60mg/m^2 (or epirubicin 90 mg/m^2) IV infusion Q3W and cyclophosphamide 600 mg/m^2 IV infusion Q3W for 12 weeks. At 3 to 6 weeks after last dose of neoadjuvant treatment, participants will undergo surgery for their breast cancer. After surgery, participants will receive adjuvant pembrolizumab 400 mg IV infusion Q6W for approximately 30 weeks. Additional adjuvant TPC may be administered to participants with residual disease. TPC options include olaparib 300 mg oral BID for 1 year (participants with gBRCAm only) or capecitabine 1000-1250 mg/m^2 oral BID days 1-14 and 22-35 Q6W for 4 six-week cycles.
Receives: Biological: Pembrolizumab; Drug: Paclitaxel; Drug: Carboplatin; Drug: Doxorubicin hydrochloride; Drug: Epirubicin hydrochloride; Drug: Cyclophosphamide; Drug: Capecitabine; Drug: Olaparib

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Part 1: Number of Participants Experiencing an Adverse Event (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. The number of participants who experience an AE will be presented for Part 1.

    Measured: Up to ~43 weeks

  2. Part 1: Number of Participants Who Experience One or More Dose-Limiting Toxicities (DLTs)

    A DLT is defined by the National Cancer Institute Common Terminology for Adverse Events (NCI CTCAE) Version 5.0, assessed by investigator as drug-related: Grade (gr) 3 or 4 nonhematologic toxicity (with exceptions); gr 3 or gr 4 laboratory values (with exceptions); gr 3 or 4 febrile neutropenia; prolonged delay (>2 weeks) in initiating Cycle 2 (cycle length = 3 weeks) due to intervention-related toxicity; any intervention-related toxicity that causes the participant to discontinue intervention during Cycle 1; interstitial lung disease as per investigator; any other gr ≥3 pulmonary toxicity; or gr 5 toxicity.

    Measured: Up to 21 days

  3. Part 1: Number of Participants who Discontinued Study Treatment 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. The number of participants who discontinued study treatment due to an AE will be presented for Part 1.

    Measured: Up to ~30 weeks

  4. Part 2: Pathological Complete Response (pCR) Rate Using the Definition of ypT0/Tis ypN0

    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 at the time of definitive surgery.

    Measured: Up to ~30 weeks

  5. Part 2: Number of Participants Experiencing 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. The number of participants who experience an AE will be presented for Part 2.

    Measured: Up to ~103 weeks

  6. Part 2: Number of Participants who Discontinued Study Treatment 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. The number of participants who discontinued study treatment due to an AE will be presented for Part 2.

    Measured: Up to ~90 weeks

Secondary outcomes (5)

  1. Part 2: pCR-No Ductal Carcinoma in Situ (DCIS) Rate Using the Definition of ypT0 ypN0

    pCR-no 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 at the time of definitive surgery.

    Measured: Up to ~30 weeks

  2. Part 2: 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.

    Measured: Up to ~100 months

  3. Part 2: Overall Survival (OS)

    OS is defined as the time from randomization to date of death due to any cause.

    Measured: Up to ~100 months

  4. Part 2: Distant Progression or Distant Recurrence-Free Survival (DPDRFS)

    DPDRFS is defined as the time from randomization to first distant progression or distant recurrence event as assessed or death due to any cause, whichever occurs first.

    Measured: Up to ~100 months

  5. Part 2: Residual Cancer Burden (RCB)

    RCB is defined as residual disease in either the breast or lymph node at the time of surgery. RCB score provides a continuous measurement of the extent of residual cancer. There are four RCB classes: RCB-0 (RCB score 0), RCB-1 (0< RCB score <1.36), RCB-2 (1.36 <RCB score <3.28), and RCB-3 (RCB score >3.28).

    Measured: Up to ~30 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 Jan 2025
  2. Study start20 Mar 2025
  3. Primary completion31 Dec 2029 (estimated)
  4. Study completion16 Mar 2031 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Part 1 is non-randomized. Part 2 is randomized 1:1:1.
Masking
None (open label)
Enrolment
372 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06797635
Sponsor's protocol ID
1022-010
Other IDs
MK-1022-010, 2024-514376-40-00, U1111-1307-7867
Status last verified
Nov 2026
First submitted
21 Jan 2025
Last updated
6 Nov 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Patritumab deruxtecan, Pembrolizumab and Paclitaxel in people with Breast Neoplasms and Breast Cancer, run by Merck Sharp & Dohme LLC at 17 sites in 4 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 17 sites in United States, South Korea, Spain, Taiwan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Toll Free Number (1-888-577-8839, Trialsites@msd.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part 1: Number of Participants Experiencing an Adverse Event (AE) (time frame: Up to ~43 weeks). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06797635.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026.

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