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Taking people in United StatesPhase 2

Shorter Treatment After Surgery for Early HER2-Positive or Triple-Negative Breast Cancer

Tests less treatment after surgery in early breast cancer with no remaining tumor signs.

Key facts

Who runs it
M.D. Anderson Cancer Center
Where
Houston, United StatesSee the site
Trial code
Registry title
Ph2 Study for Optimization of Adjunct Systemic Therapy in HER2+ Patients, MolecularPCR Trial
Status
Recruiting
Phase
Phase 2
People taking part
120 people, planned
Started
9 Oct 2025
Expected to end
30 Sept 2028
Type of study
Interventional, 2 groups
Treatments tested
  • Biospecimen Collection
  • Hormone Therapy
  • Pembrolizumab
  • Pertuzumab
  • Trastuzumab
Record updated
3 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with early HER2-positive or triple-negative breast cancer. Their cancer fully cleared after treatment before surgery, and no tumor DNA shows in their blood.

Age
18 years or older.
Sex
Women and men can join.
Disease stage
Early invasive breast cancer, HER2-positive or triple-negative, clinical stage T1-4, N0-2a, M0, with no spread elsewhere. Surgery must show a complete response (ypT0-Tis, ypN0).
Earlier treatment
Must have finished treatment before surgery: trastuzumab plus pertuzumab with chemotherapy (HER2-positive), or pembrolizumab with chemotherapy (triple-negative). Must be willing to stop standard treatment after surgery. Cannot have had 4 or more cycles of it already.
Biomarker or test result
HER2-positive, or triple-negative (estrogen and progesterone receptor < 10%). Enough stored tumor tissue from the first biopsy. No tumor DNA in the blood (molecular residual disease negative).

Main reasons for not taking part

  • Tumor stage cN2b or cN3
  • Another cancer in the past 5 years, with a few skin and in situ exceptions
  • Known cancer spread (metastases) from any site
  • Uncontrolled illness, such as active infection or heart problems
  • Pregnancy

The registry criteria, word for word

Show all 30 criteriaShow less

Who can take part

  • EARLY HER2 POSITIVE (+) BREAST CANCER COHORT: Female or male with a diagnosis of biopsy proven invasive breast cancer HER2+, hormone (estrogen and progesterone)-receptor positive or negative. The HER2 status (following American Society of Clinical Oncology [ASCO]/College of American Pathologists [CAP] guidelines) and hormone-receptor status will be determined according to institutional (local) guidelines
  • EARLY TNBC COHORT: Female or male with a diagnosis of biopsy proven invasive TNBC (estrogen and progesterone receptor < 10%). The HER2 status (following ASCO/CAP guidelines) and hormone-receptor status will be determined according to institutional (local) guidelines
  • FOR BOTH HER2+ AND TNBC COHORTS: Invasive breast cancer of any tumor histologic grade and/or nuclear grade, and any tumor histological subtype including but not limited to infiltrating ductal carcinoma, infiltrating lobular carcinoma, mucinous carcinoma, papillary carcinoma, tubular carcinoma, metaplastic carcinoma, and mixed histology
  • FOR BOTH HER2+ AND TNBC COHORTS: Clinical tumor stage (per American Joint Committee on Cancer [AJCC] 8th edition): T1-4, N0-2a, M0. Patients who have a diagnosis of inflammatory breast cancer are eligible. Patients should not have clinical evidence of locoregional or distant metastatic breast cancer
  • EARLY HER2+ BREAST CANCER COHORT: Have completed NST with a trastuzumab plus pertuzumab and chemotherapy-based regimen (for example, docetaxel plus minus carboplatin plus trastuzumab plus pertuzumab known as the docetaxel/pertuzumab/trastuzumab [THP]/carboplatin/paclitaxel/pertuzumab/trastuzumab [TCHP] regimens) followed by definitive breast surgery where the surgical pathology reports a pCR (ypT0-Tis, ypN0) and are willing to discontinue adjuvant trastuzumab plus pertuzumab
  • EARLY TNBC COHORT: Have completed NST with a pembrolizumab plus chemotherapy-based regimen (for example, the KEYNOTE-522 regimen which is paclitaxel plus carboplatin plus pembrolizumab followed by doxorubicin plus cyclophosphamide plus pembrolizumab) followed by definitive breast surgery where the surgical pathology reports a pCR (ypT0-Tis, ypN0) and are willing to discontinue adjuvant pembrolizumab
  • The surgical pathology report needs to show a pCR (ypT0-Tis, ypN0) for a patient to be able to participate in this study and all enrolled patients should be willing to discontinue standard adjuvant systemic therapy
  • FOR BOTH HER2+ AND TNBC COHORTS: Adequate archival tumor tissue from the core diagnostic biopsy (per Personalis)
  • FOR BOTH HER2+ AND TNBC COHORTS: Age ≥ 18 years
  • FOR BOTH HER2+ AND TNBC COHORTS: Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (Karnofsky ≥ 60%)
  • FOR BOTH HER2+ AND TNBC COHORTS: Absolute neutrophil count ≥ 1,000/mcL
  • FOR BOTH HER2+ AND TNBC COHORTS: Hemoglobin ≥ 9.0 g/dL
  • FOR BOTH HER2+ AND TNBC COHORTS: Platelets ≥ 100,000/mcL
  • FOR BOTH HER2+ AND TNBC COHORTS: Total bilirubin ≤ 1.5 institutional upper limit of normal (ULN); patients with Gilbert's syndrome (if direct bilirubin <1.5 x institutional ULN)
  • FOR BOTH HER2+ AND TNBC COHORTS: Aspartate aminotransferase (AST)(serum glutamic oxaloacetic transaminase [SGOT])/ alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase [SGPT]) ≤ 3 × institutional ULN
  • FOR BOTH HER2+ AND TNBC COHORTS: Creatinine ≤ 1.5 mg/dL
  • FOR BOTH HER2+ AND TNBC COHORTS: For patients with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated
  • FOR BOTH HER2+ AND TNBC COHORTS: Patients with a history of hepatitis C virus (HCV) infection must have been treated and cured. For patients with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load
  • FOR BOTH HER2+ AND TNBC COHORTS: Human immunodeficiency virus (HIV)-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible
  • FOR BOTH HER2+ AND TNBC COHORTS: Pre- and postmenopausal women are eligible
  • FOR BOTH HER2+ AND TNBC COHORTS: Ability to understand and the willingness to sign a written informed consent document

Who cannot take part

  • Patients who are receiving any other anti-cancer investigational agents
  • Blood transfusion within 2 weeks before collection of blood for ctDNA testing
  • Patients who have received 4 or more cycles of SOC adjuvant trastuzumab/pertuzumab (HER2+) or 4 or more cycles of SOC adjuvant pembrolizumab (TNBC)
  • History of other malignancies besides breast cancer within the past 5 years, except cervical cancer in situ, melanoma in situ, basal cell carcinoma of the skin, or squamous cell carcinoma of the skin
  • Patients with known cancer metastases from any site
  • Patients with uncontrolled intercurrent illness including but not limited to active infection, symptomatic congestive heart failure, unstable angina pectoris, symptomatic cardiac arrythmias
  • Patients with psychiatric illness/social situations that would limit compliance with study requirements
  • Patients with tumor stage of cN2b or cN3 are not eligible
  • Pregnant women are not eligible to participate in this study

Where in United States

  • M D Anderson Cancer CenterHouston, United StatesContact: Vicente Valero, MDTaking people

About the trial

What the trial wants to find out

This phase II trial tests reduced post surgery (adjuvant) therapy for patients with early breast cancer who have confirmed that the disease has responded completely (pathologic complete response) after pre surgical treatment (neoadjuvant) therapy and do not have any tumor genetic material (molecular residual disease) circulating in their blood. Standard of care treatment after surgery consists of 1 year of pembrolizumab for patients with triple negative breast cancer or trastuzumab with or without pertuzumab to complete 1 year of treatment. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Pertuzumab and trastuzumab are monoclonal antibodies and forms of targeted therapy that attach to a receptor protein called HER2. HER2 is found on some cancer cells. When pertuzumab or trastuzumab attach to HER2, the signals that tell the cells to grow are blocked and the tumor cell may be marked for destruction by the body's immune system. Lowering the total amount of cancer therapy after breast surgery, may continue to keep the great tumor response to treatment, and may help lower the amount of side effects patients have.

The 2 groups in the trial

  • Cohort 1 (Triple negative breast cancer)Treatment being tested

    Patients may receive 1 to 3 cycles of standard of care treatment with pembrolizumab. Patients with a positive ctDNA test 4-6 weeks after surgery continue to receive standard of care treatment per their treating physician in the absence of disease progression or unacceptable toxicity. Patients with a negative ctDNA test will not receive further treatment with pembrolizumab and will undergo monitoring with ctDNA tests every 3 months for 3 years in the absence of disease progression. Patients undergo blood sample collection throughout the study.

    Treatment: Biospecimen Collection and Pembrolizumab

  • Cohort 2 (HER2 positive breast cancer)Treatment being tested

    Patients may receive 1 to 3 cycles of standard of care treatment with trastuzumab with or without pertuzumab. Patients with a positive ctDNA test 4-6 weeks after surgery continue to receive standard of care treatment per their treating physician in the absence of disease progression or unacceptable toxicity. Patients with a negative ctDNA test will not receive further treatment with pembrolizumab and will undergo monitoring with ctDNA tests every 3 months for 3 years in the absence of disease progression. Patients may receive standard of care endocrine therapy per their treating physician throughout the study. Patients undergo blood sample collection throughout the study.

    Treatment: Biospecimen Collection, Hormone Therapy, Pertuzumab, and Trastuzumab

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Optimization of Adjuvant Systemic Therapy in Patients With Early HER2-Positive (HER2+) Breast Cancer or Triple Negative Breast Cancer (TNBC) That Achieved a Pathological Complete Response (pCR) After Neoadjuvant Systemic Therapy and Do Not Have Molecular Residual Disease (MRD-Negative): A Phase II Clinical Trial (The MolecularPCR Trial)
Plain-language title
Shorter Treatment After Surgery for Early HER2-Positive or Triple-Negative Breast CancerGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 13 November 2026.
Record updated
3 November 2026