NCT06876714 · Alliance for Clinical Trials in Oncology
ShortStop-HER2: 12 Months vs. 6 Months of HER2-targeted Medications for People With HER2+ Breast Cancer Who Had a Pathologic Complete Response After Chemotherapy Plus Trastuzumab
What this study is about
This phase III trial compares 6 months of human epidermal growth factor receptor 2 (HER2)-targeted therapy to 12 months of HER2-targeted therapy for the treatment of HER2-positive (+) breast cancer in patients that had a pathologic full disappearance of disease signs (pCR) after preoperative (neoadjuvant) chemotherapy with trastuzumab.
View original scientific description
This phase III trial compares 6 months of human epidermal growth factor receptor 2 (HER2)-targeted therapy to 12 months of HER2-targeted therapy for the treatment of HER2-positive (+) breast cancer in patients that had a pathologic complete response (pCR) after preoperative (neoadjuvant) chemotherapy with trastuzumab. Trastuzumab and pertuzumab are monoclonal antibodies and forms of targeted therapy that attach to a receptor protein called HER2. HER2 is found on some cancer cells.
Interventions
BIOLOGICAL
Trastuzumab (Herceptin)
Given IV or SC
BIOLOGICAL
Pertuzumab
Given IV or SC
PROCEDURE
Echocardiography
Undergo ECHO
PROCEDURE
Multigated Acquisition Scan
Undergo MUGA
PROCEDURE
Mammography
Undergo mammography
PROCEDURE
Ultrasound
Undergo ultrasound
PROCEDURE
Magnetic Resonance Imaging
Undergo MRI
PROCEDURE
Biospecimen Collection
Undergo blood and tissue sample collection
OTHER
Questionnaire Administration
Ancillary studies
Primary outcome measures
Recurrence-free survival (RFS)
Time frame: From randomization to invasive local, regional or distant breast cancer recurrence, or death from any cause prior to a documented disease recurrence, assessed up to 10 years
The Kaplan-Meier method will be used to estimate the distribution of RFS times and a stratified log-rank test for non-inferiority will be used to assess whether RFS with 6 total months of human epidermal growth factor receptor 2 (HER2)-blockade is non-inferior to standard-of-care 12 total months of HER2-blockade in this patient population. Stratified Cox modeling will be used to estimate the hazard ratio and corresponding one-sided 95% confidence interval (CI).
Functional Assessment of Cancer Therapy-Breast (FACT-B) total score (Quality of life)
Time frame: At 12 months
Will compare the FACT-B total score between patients randomized to receive 6 months versus 12 months of combined neoadjuvant/adjuvant HER2 blockade. All questionnaires will be scored according to published scoring algorithms, including recommendations for addressing missing items within a scale. An intention-to-treat (ITT) approach will be used for all analyses. All statistical tests will be 2-sided, and p-values \< 0.05 will be considered statistically significant. To evaluate the between-arm mean difference in scores, a repeated measures mixed model will be estimated based on FACT-B total scores at all time points.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Patients (females and males) with clinical stage T1c-T3 (or Tx) and nodal stage N0-N1 (except T3N1 tumors, which are not eligible)
- Patients must have no residual invasive disease in the breast or lymph nodes after the completion of neoadjuvant therapy. Residual ductal carcinoma in situ (DCIS) is allowed. Patients with residual isolated tumor cells at surgery are considered node-positive and are not eligible
- HER2+ by American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. Central pathology review is not required. In cases where there were multiple tumor sites in breast/nodes that had HER2 testing at diagnosis, at least one site must have been HER2+ AND the treating investigator must feel it is in the patient's best interest to be treated as having HER2+ breast cancer
- Known hormone receptor status as defined by ASCO/CAP guidelines. Estrogen receptor (ER) and progesterone receptor (PR) of any values are allowed. Hormone
Where
- Phoenix, Arizona
- Fort Smith, Arkansas
- Jonesboro, Arkansas
- Little Rock, Arkansas
- Arroyo Grande, California
- Beverly Hills, California
- Carmichael, California
- Chico, California
- Dublin, California
- Elk Grove, California
- Emeryville, California
- Fremont, California
And 513 more locations — see the full list below.
Collaborators
National Cancer Institute (NCI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 5, 2026 · Source of record for eligibility and locations