Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07060807

A Clinical Study of Patritumab Deruxtecan to Treat Breast Cancer (MK-1022-016)

Researchers are looking for other ways to treat breast cancer (BC) that is hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) and either unresectable locally advanced or metastatic.

* HR positive (HR+) means the cancer cells have proteins that attach to estrogen or progesterone (hormones) which help the cancer to grow and spread * HER2 negative (HER2-) means the cancer cells have a low amount of a protein called HER2 * Unresectable locally advanced means the cancer cannot be completely removed by surgery and has spread into nearby tissue or muscles * Metastatic means the cancer has spread to other parts of the body

Treatment for this type of breast cancer usually includes endocrine therapy (ET) and sometimes a second treatment. The main goal of this study is to learn if people who receive patritumab deruxtecan (also known as HER3-DXd and MK-1022) live longer overall or without the cancer growing/spreading, compared to people who receive chemotherapy or a different drug called trastuzumab deruxtecan.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Breast Neoplasms Breast Diseases Neoplasms Neoplasms by Site Skin Diseases Skin and Connective Tissue Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Hospital Aleman ( Site 0200), Ciudad Autonoma de Buenos Aires, Buenos Aires, Argentina

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

  • Has a diagnosis of hormone receptor positive (HR+)/human epidermal growth factor receptor 2 (HER2)- invasive breast carcinoma that is either locally advanced disease not amenable to resection with curative intent (herein called unresectable) or metastatic disease not treatable with curative intent
  • Has centrally-confirmed HR+ and HER2- results and human epidermal growth factor receptor 3 (HER3) evaluable results from a biopsy obtained from a distant metastatic site or a locally advanced lesion on or after the most recent line of therapy (with certain exceptions)
  • Must have had progression or recurrence on prior cyclin-dependent kinase (CDK)4/6 inhibitor + endocrine therapy (ET) with one of the following:
  • Radiographic disease progression, as assessed by the investigator, on CDK4/6 inhibitor + ET as 1L for treatment of unresectable locally advanced or metastatic HR+/HER2- breast cancer. CDK4/6 inhibitor + ET must be the only line of therapy received in the advanced setting, or
  • Disease recurrence, either radiographic and/or confirmed histologically via biopsy as assessed by the investigator, while on adjuvant ET in combination with a CDK4/6 inhibitor OR within 24 months from the date of last dose of adjuvant CDK4/6 inhibitor
  • Has measurable disease per RECIST 1.1 as assessed by the local site investigator/radiology
  • Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on antiretroviral therapy
  • Has an Eastern Cooperative Oncology Group performance status of 0 or 1 assessed within 7 days before randomization

Exclusion criteria

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

  • Has breast cancer amenable to treatment with curative intent
  • Is eligible to receive additional endocrine-based treatment in the advanced setting as determined by the investigator
  • Has a known germline breast cancer gene (BRCA) mutation (deleterious or suspected deleterious) where poly (ADP-ribose) polymerase (PARP) inhibitor(s) is a potential treatment option
  • Has current visceral crisis or is at risk for impending visceral crisis that has or may cause imminent organ compromise and/or other life-threatening complications
  • Has any of the following: a pulse oximeter reading <92% at rest, or requires intermittent supplemental oxygen, or requires chronic supplemental oxygen
  • Has uncontrolled, significant cardiovascular disease or cerebrovascular disease
  • Has ≥Grade 2 peripheral neuropathy.
  • Has clinically significant corneal disease
  • Has received prior chemotherapy for unresectable locally advanced or metastatic breast cancer
  • Has received prior treatment with an anti-HER3 antibody and/or antibody-drug conjugate that consists of a topoisomerase I inhibitor (eg, T-DXd) or any other topoisomerase I inhibitor therapy
  • Has received prior systemic anticancer therapy within 4 weeks (or 5 half-lives, whichever is shorter) before randomization; participants previously treated with ET plus a CDK4/6 inhibitor may participate as long as at least 2 weeks have elapsed since the last dose of therapy was administered
  • Has received prior radiotherapy for non-central nervous system disease, or required corticosteroids for radiation-related toxicities, within 14 days of the first dose of study intervention
  • Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy
  • Has known additional malignancy that is progressing or has required active treatment within the past 3 years
  • Has history of (noninfectious) pneumonitis/interstitial lung disease (ILD) that required steroids, has current pneumonitis/interstitial lung disease, or has suspected ILD/pneumonitis that cannot be ruled out by imaging at Screening
  • Has severe hypersensitivity (≥Grade 3) to HER3-DXd and/or any of its excipients
  • Has severe hypersensitivity (≥Grade 3) to all the available TPC and/or any of their excipients

Treatment and study plan

Patritumab deruxtecan

Biological

Administered via intravenous (IV) infusion

Other names: MK-1022, HER3-DXd, U3-1402

paclitaxel

Drug

Administered via IV infusion

Other names: TAXOL®, ONXAL®

Nab-paclitaxel

Drug

Administered via IV infusion

Other names: Abraxane®

Capecitabine

Drug

Administered via oral tablets

Other names: XELODA®

Liposomal Doxorubicin

Drug

Administered via IV infusion

Other names: Doxil®

Trastuzumab Deruxtecan

Biological

Administered via IV infusion

Other names: T-DXd, Enhertu®

Primary outcomes

  1. Progression Free Survival (PFS)

    Time frame: Up to approximately 45 months

    PFS is defined as the time from first day of study intervention to the first documented progressive disease (PD) or death due to any cause, whichever occurs first as assessed by blinded independent central review (BICR). Per Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, PD is defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions is also considered PD. The appearance of one or more new lesions is also considered PD. PFS as assessed by BICR will be presented.

  2. Overall Survival (OS)

    Time frame: Up to approximately 85 months

    OS is the length of time from when the participant starts treatment until death from any cause.

Secondary outcomes

  1. Objective Response Rate (ORR)

    Time frame: Up to approximately 85 months

    ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1 as assessed by BICR.

  2. Duration of Response (DOR)

    Time frame: Up to approximately 85 months

    For participants who demonstrate a confirmed Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1, DOR is defined as the time from first documented evidence of CR or PR until progressive disease (PD) or death. Per RECIST 1.1, PD is defined as at least a 20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of one or more new lesions is also considered PD. DOR as assessed by BICR will be presented.

  3. Change from Baseline in the European Organization for Research and Treatment of Cancer (EORTC)-Quality of Life Questionnaire-Core 30 (QLQ-C30) Global Health Status (Item 29) and Quality of Life (Item 30) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of life (QoL) questionnaire. Participant responses to the questions regarding Global Health Status (GHS; "How would you rate your overall health during the past week?") and Quality of Life (QoL; "How would you rate your overall quality of life during the past week?") are scored on a 7-point scale (1= Very poor to 7=Excellent). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A higher score indicates a better outcome. The change from baseline in GHS (EORTC QLQ-C30 Item 29) and QoL (EORTC QLQ-C30 Item 30) combined score (the standardized average of the raw scores) will be presented.

  4. Change from Baseline in the EORTC-QLQ-C30 Physical Functioning (Items 1-5) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of-life questionnaire. Participant responses to 5 questions about their physical functioning (Items 1-5) are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. Higher scores indicate better physical functioning. The change from baseline in EORTC QLQ-C30 Physical Functioning (Items 1-5) combined score (the standardized average of the raw scores) will be presented.

  5. Change from Baseline in the EORTC-QLQ-C30 Emotional Functioning (Items 1-5) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of-life questionnaire. Participant responses to 4 questions about their emotional functioning (Items 21-24) are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. Higher scores indicate better emotional functioning. The change from baseline in EORTC QLQ-C30 Emotional Functioning (Items 21-24) combined score (the standardized average of the raw scores) will be presented.

  6. Change from Baseline in the EORTC-QLQ-C30 Pain (Items 9 and 19) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of-life questionnaire. Participant responses to 2 questions about their pain (Items 9 and 19) are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. Higher scores indicate greater pain. The change from baseline in EORTC QLQ-C30 Pain (Items 9 and 19) combined score (the standardized average of the raw scores) will be presented.

  7. Time to First Deterioration (TTD) in the European Organization for Research and Treatment of Cancer (EORTC)-Quality of Life Questionnaire-Core 30 (QLQ-C30) Global Health Status (Item 29) and Quality of Life (Item 30) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of life (QoL) questionnaire. Participant responses to the questions regarding Global Health Status (GHS; "How would you rate your overall health during the past week?") and Quality of Life (QoL; "How would you rate your overall quality of life during the past week?") are scored on a 7-point scale (1= Very poor to 7=Excellent). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A higher score indicates a better outcome. The TTD from baseline in GHS (EORTC QLQ-C30 Item 29) and QoL (EORTC QLQ-C30 Item 30) combined score (the standardized average of the raw scores), defined as the time from baseline to the first onset of a 10 or more points deterioration from baseline, will be presented.

  8. TTD in the EORTC-QLQ-C30 Physical Functioning (Items 1-5) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of-life questionnaire. Participant responses to 5 questions about their physical functioning (Items 1-5) are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. Higher scores indicate better physical functioning. The TTD from baseline in EORTC QLQ-C30 Physical Functioning (Items 1-5) combined score (the standardized average of the raw scores), defined as the time from baseline to the first onset of a 10 or more points deterioration from baseline, will be presented.

  9. TTD in the EORTC-QLQ-C30 Emotional Functioning (Items 1-5) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of-life questionnaire. Participant responses to 4 questions about their emotional functioning (Items 21-24) are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. Higher scores indicate better emotional functioning. The TTD from baseline in EORTC QLQ-C30 Emotional Functioning (Items 21-24) combined score (the standardized average of the raw scores) defined as the time from baseline to the first onset of a 10 or more points deterioration from baseline, will be presented.

  10. TTD in the EORTC-QLQ-C30 Pain (Items 9 and 19) Combined Score

    Time frame: Baseline and up to approximately 85 months

    The EORTC QLQ-C30 is a cancer specific health-related quality-of-life questionnaire. Participant responses to 2 questions about their pain (Items 9 and 19) are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. Higher scores indicate greater pain. The TTD from baseline in EORTC QLQ-C30 Pain (Items 9 and 19) combined score (the standardized average of the raw scores), will be presented.

  11. Number of Participants Who Experience One or More Adverse Event (AEs)

    Time frame: Up to approximately 85 months

    An AE is any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. The number of participants who experience an AE will be presented.

  12. Number of Participants Who Discontinue Study Treatment Due to an AE

    Time frame: Up to approximately 85 months

    An AE is any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. The number of participants who discontinue study treatment due to an AE will be presented.

Study contacts

Contact information is provided by the study sponsor or research team.

Toll Free Number

CONTACT

[email protected]

1-888-577-8839

Sponsors and collaborators

Lead sponsor

Merck Sharp & Dohme LLC

Industry

Collaborators

  • Daiichi Sankyo

Registry information

Official study title

An Open-label, Randomized, Phase 3 Study to Evaluate Patritumab Deruxtecan Monotherapy Versus Treatment of Physician's Choice in Hormone Receptor-positive, HER2-negative Unresectable Locally Advanced or Metastatic Breast Cancer (HERTHENA-Breast04).

Important dates

Study start
2025
Primary completion
2033
Study completion
2033
First posted
Jul 11, 2025
Registry last updated
Jul 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.