Breast CancerPhase 2NCT03587740
ATOP TRIAL: T-DM1 in HER2 Positive Breast Cancer
A Phase 2 study testing T-DM1 in people with Breast Cancer, run by Dana-Farber Cancer Institute at 14 sites in United States.
Trial summary
This research study is studying an investigational drug as a possible treatment for breast cancer that is positive for the protein Human Epidermal Growth Factor Receptor 2, also known as HER2-positive breast cancer. The drug involved in this study is: -ado-trastuzumab emtansine (T-DM1) Read more about this study
- Who is it for?
- Ages 60 years and older
- Conditions the study is for
- Breast Cancer
- What is being tested?
- T-DM1
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 111 participants
- Where
- 14 sitesUnited States
- Study dates
- 22 Aug 2018to 30 Aug 2027
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 60 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participants must have histologically or cytologically confirmed HER2-positive disease by local pathology, defined as immunohistochemistry (IHC) 3+ or amplification by FISH (HER2/CEP17 ratio ≥2 or an average of ≥6 HER2 gene copies per nucleus) AND confirmed by Central Pathology Review (Dr. Deborah Dillon at Brigham and Women's Hospital, Boston, MA) prior to patient being registered to begin protocol therapy. See section 3.4. http://ascopubs.org/doi/full/10.1200/jco.2013.50.9984
- NOTE: DCIS components should not be counted in the determination of HER2 status.
- Age ≥60 years at the time of study registration (men and women eligible)
- Participants must have histologically or cytologically confirmed Stage I-III breast cancer with the following criteria met:
- If node-negative or if node status unknown (because it was not assessed), tumor must be >5 mm of any hormone receptor subtype (document ER/PR status: if some ER/PR staining is present, ER and PR negative are defined as being positive in <10% cells [per local pathology read]).
- If node-positive (N1-N3), T1mi, T1a, T1b, T1c, T2, or T3 tumors are eligible (see below for further details on defining node-negative disease) Definition of node-negative disease (when node status known): If the patient has had a negative sentinel node biopsy and/or a negative axillary dissection, then the patient is determined to be node-negative. Axillary nodes with single cells or tumor clusters ≤ 0.2 mm by either H\&E or IHC will be considered node-negative. Any axillary lymph node with tumor clusters between 0.02 and 0.2cm is considered a micrometastasis. Patients with a micrometastasis are eligible even if their tumor is </= 5mm. An axillary dissection is not required to be performed in patients with a positive sentinel node and management of the axilla will be left up to the treating provider. In cases where the specific pathologic size of lymph node involvement is subject to interpretation, the principal investigator will make the final determination as to eligibility. In these special situations, the investigator must document this approval in the patient medical record.
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- ER/PR determination assays performed by IHC methods according to the local institution standard protocol.
- Standard chemotherapy/trastuzumab declined by patient OR patient is deemed by physician for any reason to not be a candidate for standard therapy (i.e. patient and/or provider choose not to pursue standard trastuzumab-based chemotherapy regimen because of concerns related to toxicity or provider/patient preference).
- For patients with bilateral or multifocal/multicentric breast cancers, one of the following criteria must be met to enroll: (1) each cancer individually meets criteria for enrollment (only ONE tumor has to undergo central confirmation for HER2), (2) at least one tumor meets eligibility (per tumor size/nodes/subtype outlined above) and the other foci in the ipsilateral or contralateral breast are also HER2-positive but are too small for enrollment (e.g., a patient is eligible if a cancer is T2N0 and HER2-positive in one breast, but the contralateral breast has a T1a HER2+ cancer that isn't eligible on its own, (3) there is at least one qualifying tumor of >5mm but there are other small foci of disease that are too small to test for ER/PR/HER2 and are felt to be a part of the same tumor or similar tumor, OR (4) at least one tumor meets eligibility and the other foci in the ipsilateral or contralateral breast are HER2-negative and do not meet criteria for adjuvant chemotherapy per provider discretion (e.g. if a patient has a HER2-positive tumor meeting eligibility but also has a second, HER2-negative, small, node-negative, ER+, low grade cancer present, she is still eligible for enrollment). However, in the specific case that a second breast cancer is stage III and HER2-negative, that patient is excluded (because the second cancer is high-risk and likely will require non-HER2-directed therapy).
- All tumor removed by either a modified radical mastectomy or a segmental mastectomy (lumpectomy).
- NOTE: Management of axillary lymph nodes is up to the treating provider; however, all surgical margins should be clear of invasive cancer or DCIS (i.e., no tumor on ink). The local pathologist must document negative margins of resection in the pathology report. If all other margins are clear, a positive posterior (deep) margin is permitted, provided the surgeon documents that the excision was performed down to the pectoral fascia and all tumor has been removed. Likewise, if all other margins are clear, a positive anterior (superficial; abutting skin) margin is permitted provided the surgeon documents that all tumor has been removed.
- -≤90 days from the patient's most recent breast surgery for this breast cancer. Note: In cases where registration will occur >90 days from surgery but within an acceptable time frame, patient may be eligible for enrollment with approval from the PI, Rachel Freedman MD, MPH.
- ECOG Performance Status (PS) 0-2. See Appendix F.
- Baseline ejection fraction ≥50% by MUGA scan or echocardiogram performed ≤60 days prior to registration.
- The following laboratory values obtained ≤14 days prior to registration:
- Absolute neutrophil count (ANC) ≥1500/mm3
- Platelet count ≥100,000/mm3
- Hemoglobin >9.0 g/dL
- Total bilirubin ≤1.5 x upper limit of normal (ULN). If patient has known Gilbert's syndrome, the suggested threshold for treatment is a total bilirubin ≤2.0 x ULN, but will be left to the treating providers discretion.
- AST and ALT ≤2.5 x ULN, alkaline phosphatase ≤2.5 x ULN
- INR <1.5 x ULN for institution unless patient is on planned therapy with anticoagulants (i.e., warfarin) with higher target planned. In those cases, INR up to 3.5 is acceptable.
- PTT <1.5 x ULN for institution unless patient is on planned therapy with heparin or heparin-like products Note: In the case of longstanding ethnic neutropenia, patient may be eligible for enrollment with approval from the PI, Rachel Freedman MD, MPH.
- Life expectancy >5 years per provider's assessment
- Willing to employ adequate and appropriate birth control if applicable
- NOTE: This study is for patients aged 60 and older, and most female patients will have entered menopause by this time; however patients should not become pregnant while on this study because T-DM1 can affect an unborn baby. Pre-menopausal women need to use birth control while on this study and women should not breastfeed a baby while on this study. Any man treated on this study will also need to use contraception if his partner is a premenopausal female. Patients should check with their health care provider about what kind of birth control methods to use and how long to use them.
- Negative urine or serum pregnancy test done ≤7 days prior to registration, for women of childbearing potential only
- NOTE: In the rare case that a woman enrolling on study is of childbearing potential, a pregnancy test is required prior to enrollment on study.
- Able to provide informed written consent.
- Willing to return to consenting institution for follow-up at 6 months
- Willing to provide blood samples for mandatory correlative research purposes.
- Ability to understand and the willingness to sign a written informed consent document
Who cannot join
- Evidence of metastatic disease.
- Patients will not require baseline staging PET or CT chest, abdomen, pelvis or bone scan to rule out metastatic disease prior to enrollment. Any staging scans will be ordered at the treating provider's discretion. If metastatic disease is found on any staging studies done, patients will not be eligible for enrollment.
- Locally advanced tumors at diagnosis (T4), including tumors fixed to the chest wall, peau d'orange, skin ulcerations/nodules, or clinical inflammatory changes (diffuse brawny cutaneous induration with an erysipeloid).
- Patients with stage III, HER2-negative cancer in the contralateral breast (see 3.1.6 above).
- Positive Hepatitis B (Hepatitis B surface antigen and antibody) and/or Hepatitis C (Hepatitis C antibody test) as indicated by serologies conducted ≤3 months prior to registration if liver function tests are outside of the normal institutional range.
- NOTE: A hepatitis panel is required of all participants as part of screening. Patients with positive Hepatitis B or C serologies indicating active infection without known active disease must meet the eligibility requirements for ALT, AST, total bilirubin, INR, PTT, and alkaline phosphatase on at least two consecutive occasions, separated by at least 1 week. Patients with laboratory evidence of vaccination to Hepatitis B (e.g., positive antibodies) are eligible.
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- Active liver disease, for example, due to autoimmune hepatic disorder, or sclerosing cholangitis.
- Significant, active cardiopulmonary dysfunction (i.e. uncontrolled heart issues)as indicated by MUGA or echocardiogram performed ≤60 days prior to registration and/or by presence of any of the following:
- History of NCI CTCAE (Version 4.0) Grade ≥3 symptomatic congestive heart failure (CHF) or NYHA criteria Class ≥ II
- Angina pectoris requiring anti-anginal medication, serious cardiac arrhythmia not controlled by adequate medication, severe conduction abnormality, or clinically significant valvular disease
- High-risk uncontrolled arrhythmias (i.e., atrial tachycardia with a heart rate > 100/min at rest, significant ventricular arrhythmia [ventricular tachycardia], or higher-grade atrioventricular [AV]-block [second degree AV-block Type 2 [Mobitz 2] or third degree AV-block]); if adequately and safely treated, patient may be eligible.
- Significant symptoms (Grade ≥ 2) relating to left ventricular dysfunction, cardiac arrhythmia, or cardiac ischemia
- Myocardial infarction within 12 months prior to registration
- Uncontrolled hypertension (systolic blood pressure > 180 mmHg and/or diastolic blood pressure >100 mmHg)
- Evidence of transmural infarction on ECG
- Requirement for oxygen therapy
- Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens.
- Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection or psychiatric illness/social situations that would limit compliance with study requirements.
- Currently receiving any other investigational agent which would be considered as a treatment for the primary neoplasm.
- Concurrent second malignancy or past malignancy with >30% estimated risk of relapse in next 5 years. EXCEPTIONS: Non-melanotic skin cancer or carcinoma-in-situ of the cervix in addition to smoldering pre-malignant or malignant conditions with minimized concern for clinical progression during treatment such as MGUS or CLL, based on treating provider's assessment. -NOTE: If there is a history or prior malignancy, patient must not be receiving active treatment for this malignancy cancer.
- Any prior treatment with T-DM1 or any trastuzumab therapy.
- Any neoadjuvant chemotherapy for this breast cancer.
- ->90 days of tamoxifen therapy, or other hormonal therapy, for adjuvant therapy for this malignancy
- NOTE: If the patient has received <90 days of such therapy but is still receiving it at the time of entry into the study, patient must temporarily stop the therapy prior to Cycle 1 Day 1. The therapy can re-start only after 6 weeks of T-DM1 have been administered (anytime after C3D1).
- History of exposure at any time to the following cumulative doses of anthracyclines:
- Doxorubicin or liposomal doxorubicin >500mg/m2.
- Epirubicin >900mg/m2.
- Mitoxantrone >120 mg/m2.
- Another anthracycline, or more than one anthracycline used in a cumulative dose exceeding the equivalent of doxorubicin 500mg/m2.
- History of intolerance (including Grade 3 or 4 infusion reactions) to murine proteins.
- History of previous invasive breast cancer ≤5 years.
- NOTE: History of DCIS, LCIS is allowed.
Trial locations and contacts
14 sites in 1 country.
14 sites in 1 country
United States14 sites
Dana Farber Cancer Institute
Boston, Massachusetts, 02215
Massachusetts General Hospital
Boston, Massachusetts, 02215
Dana-Farber Cancer Institute at St. Elizabeth's Medical Center
Brighton, Massachusetts, 02135
University of North Carolina
Chapel Hill, North Carolina, 27599
City of Hope Comprehensive Cancer Center
Duarte, California, 91010
Dana-Farber/New Hampshire Oncology-Hematology
Londonderry, New Hampshire, 03053
Dana-Farber/Brigham and Women's Cancer Center at Milford Regional Medical Center
Milford, Massachusetts, 01757
Sarah Cannon Research Institute
Nashville, Tennessee, 37203
Memorial Sloan Kettering Cancer Center
New York, New York, 10065
Lifespan Cancer Institute
Providence, Rhode Island, 02903
Rex Cancer Center
Raleigh, North Carolina, 27607
Mayo Clinic
Rochester, Minnesota, 55905
Dana-Farber/Brigham and Women's Cancer Center in clinical affiliation with South Shore Hospital
South Weymouth, Massachusetts, 02190
The Stamford Hospital
Stamford, Connecticut, 06904
About this study
Official title: ATOP TRIAL: Adjuvant Ado-Trastuzumab Emtansine (T-DM1) for Older Patients With Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Breast Cancer
This research study is studying an investigational drug as a possible treatment for breast cancer that is positive for the protein Human Epidermal Growth Factor Receptor 2, also known as HER2-positive breast cancer.
The drug involved in this study is:
-ado-trastuzumab emtansine (T-DM1)
Read the detailed description
This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational drug to learn whether the drug works in treating a specific disease. "Investigational" means that the drug is being studied and research doctors are trying to find out more about it-such as the safest dose to use and the side effects it may cause.
The purpose of this research study is to examine the long-term benefits of T-DM1 with regard to breast cancer and take a closer look at the side effects experienced by participants receiving T-DM1.
The FDA (the U.S. Food and Drug Administration) has not approved T-DM1 for use in patients with stage I, II, or III breast cancer, but it has been approved for use in advanced, previously treated, HER2-positive breast cancer.
T-DM1 is an antibody-drug conjugate; it is made up of an antibody (trastuzumab) linked to a cytotoxic drug, DM1 (chemotherapy). T-DM1 functions as a targeted cancer therapy because it targets HER2-positive breast cancer cells directly, limiting exposure of the rest of the body to chemotherapy. More specifically, the trastuzumab in T-DM1 first binds to the HER2 protein on the surface of the breast cancer cells and the DM1 then enters the cells and can cause them to die, preventing tumor growth
- Conditions
- Breast Cancer
- Being tested
- T-DM1
- Keywords
- Breast Cancer
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
T-DM1Drug
Also called Kadcyla
T-DM1 is an antibody-drug conjugate; it is made up of an antibody (trastuzumab) linked to a cytotoxic drug, DM1 (chemotherapy). T-DM1 functions as a targeted cancer therapy because it targets HER2-positive breast cancer cells directly, limiting exposure of the rest of the body to chemotherapy.
| Study group | Role | What they receive |
|---|---|---|
| T-DM1 | Experimental | T-DM1 will be administered every 3 weeks intravenously, with 21 consecutive days defined as a treatment. Receives: Drug: T-DM1 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Invasive Disease-free Survival Rate (IDFS)
IDFS is defined as the time from the first T-DM1 dose to ipsilateral invasive breast cancer recurrence, regional invasive breast cancer recurrence, distant recurrence, death due to any cause, contralateral invasive breast cancer, or a second non-breast primary cancer, whichever occurs first. Patients without one of these events at the time of data analysis will be censored at the date last known to be alive and event-free. Survival probabilities (reported as percentages) are estimated from Kaplan Meier methods.
Measured: 5 years
Secondary outcomes (8)
Invasive Breast Cancer-free Survival (IBCFS)
IBCFS is defined as the time from the first T-DM1 dose to ipsilateral invasive breast cancer recurrence, regional invasive breast cancer recurrence, distant recurrence, death due to any cause, or contralateral invasive breast cancer, whichever occurs first. Patients who experience a second non-breast new primary outcome will be censored at their new primary diagnosis date. Patients without any of these events at the time of data analysis will be censored at the date last known to be alive and event-free. Survival probabilities (reported as percentages) are estimated from Kaplan Meier methods.
Measured: 5 years
Recurrence-free Interval (RFI)
RFI is defined as the time from the first T-DM1 dose to ipsilateral invasive breast cancer recurrence, regional invasive breast cancer recurrence, or distant recurrence. Patients who experience other IDFS events, such as contralateral invasive breast cancer, a second non-breast primary cancer, or death due to any cause, will be censored at the time of these events. Patients without any of these events at the time of data analysis will be censored at the date last known to be alive and event-free. Survival probabilities (reported as percentages) are estimated from Kaplan Meier methods.
Note: The protocol labels this outcome as recurrence-free survival (RFS). However, the definition provided in the protocol, where the recurrences are considered events but deaths are not considered events, matches the definition of recurrence-free interval (RFI) provided in the STEEP version 2.0 paper (Tolaney et al., 2021).
Measured: 5 years
Overall Survival (OS)
OS defined as the time from the first T-DM1 dose to death attributable to any cause (i.e. death from breast cancer, non-breast cancer cause, or from unknown cause). Subjects alive at the time of data analysis (including those lost to follow-up) will be censored at the last known alive date. Survival probabilities (reported as percentages) estimated from Kaplan Meier methods.
Measured: 5 years
Site of First Recurrence
The site of the first IDFS event for patients receiving T-DM1, which will be tabulated as frequencies and relative frequencies. IDFS events include ipsilateral invasive breast cancer recurrence, regional invasive breast cancer recurrence, distant recurrence, death due to any cause, contralateral invasive breast cancer, or a second non-breast primary cancer.
Measured: 5 years
Incidence Rate of All Toxicities (Safety)
Among all patients who received at least one dose of T-DM1 treatment, summarize the maximum treatment-related adverse event reported per subject. Adverse events (AEs) are graded utilizing CTCAE v4.0; AEs of grade 2 to 5 are systematically reported, while grade 1 AEs are not systematically reported, so subjects with no reported AEs (grade 0) and subjects with a maximum grade 1 AE are combined into a single category. AEs are considered treatment-related if they start at or after the first dose of T-DM1 and are determined to be definitely, possibly, or probably related to T-DM1 treatment.
Measured: 2 years
Incidence Rate of Cardiac-Related Adverse Events: Left Ventricular Systolic Dysfunction
Incidence of symptomatic left ventricular systolic dysfunction in patients receiving T-DM1, recorded as frequencies and percentages.
Measured: 2 years
Incidence Rate of Cardiac-Related Adverse Events: Cardiac Death
Incidence of deaths due to a cardiac event in patients receiving T-DM1, recorded as frequencies and percentages.
Measured: 2 years
Incidence Rate of Cardiac-Related Adverse Events: Decreased Ejection Fraction
Incidence of a decrease in ejection fraction by at least 10 percentage points below baseline (measured by an absolute difference) or an ejection fraction below 50%.
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2018
- Study start22 Aug 2018
- Primary completion3 Mar 2025
- Study completion30 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by Dana-Farber Cancer InstituteThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 111 participants (actual)
Sponsor and investigators
- Lead sponsor
- Dana-Farber Cancer Institute
- Sponsor type
- University, hospital or other
- Collaborators
- Susan G. Komen Breast Cancer Foundation, Gateway for Cancer Research
- Responsible party
- Principal investigator, Rachel Freedman, MD, MPH, Dana-Farber Cancer Institute
- Investigators
- Rachel Freedman, MD MPH, Principal investigator, Dana-Farber Cancer Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03587740
- Sponsor's protocol ID
- 18-124
- Status last verified
- May 2026
- First submitted
- 21 Jun 2018
- Last updated
- 18 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ATOP TRIAL: Adjuvant Ado-Trastuzumab Emtansine (T-DM1) for Older Patients With Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Breast Cancer
- ClinicalTrials.gov ID
- NCT03587740
- Acronym / sponsor ID
- 18-124
- Conditions
- Breast Cancer
- Keywords
- Breast Cancer
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 111 participants (actual)
- Lead sponsor
- Dana-Farber Cancer InstituteUniversity, hospital or other
- Collaborators
- Susan G. Komen Breast Cancer Foundation, Gateway for Cancer Research
- Study start
- 22 Aug 2018 (actual)
- Primary completion
- 3 Mar 2025 (actual)
- Study completion
- 30 Aug 2027 (estimated)
- First posted
- 16 Jul 2018 (actual)
- Results
- Posted 29 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research study is studying an investigational drug as a possible treatment for breast cancer that is positive for the protein Human Epidermal Growth Factor Receptor 2, also known as HER2-positive breast cancer.
The drug involved in this study is:
-ado-trastuzumab emtansine (T-DM1)
Detailed description
This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational drug to learn whether the drug works in treating a specific disease. "Investigational" means that the drug is being studied and research doctors are trying to find out more about it-such as the safest dose to use and the side effects it may cause.
The purpose of this research study is to examine the long-term benefits of T-DM1 with regard to breast cancer and take a closer look at the side effects experienced by participants receiving T-DM1.
The FDA (the U.S. Food and Drug Administration) has not approved T-DM1 for use in patients with stage I, II, or III breast cancer, but it has been approved for use in advanced, previously treated, HER2-positive breast cancer.
T-DM1 is an antibody-drug conjugate; it is made up of an antibody (trastuzumab) linked to a cytotoxic drug, DM1 (chemotherapy). T-DM1 functions as a targeted cancer therapy because it targets HER2-positive breast cancer cells directly, limiting exposure of the rest of the body to chemotherapy. More specifically, the trastuzumab in T-DM1 first binds to the HER2 protein on the surface of the breast cancer cells and the DM1 then enters the cells and can cause them to die, preventing tumor growth
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| T-DM1 | Experimental | Drug: T-DM1T-DM1 will be administered every 3 weeks intravenously, with 21 consecutive days defined as a treatment. |
Who may qualify
- Ages
- 60 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (31 listed)
- Participants must have histologically or cytologically confirmed HER2-positive disease by local pathology, defined as immunohistochemistry (IHC) 3+ or amplification by FISH (HER2/CEP17 ratio ≥2 or an average of ≥6 HER2 gene copies per nucleus) AND confirmed by Central Pathology Review (Dr. Deborah Dillon at Brigham and Women's Hospital, Boston, MA) prior to patient being registered to begin protocol therapy. See section 3.4. http://ascopubs.org/doi/full/10.1200/jco.2013.50.9984
- NOTE: DCIS components should not be counted in the determination of HER2 status.
- Age ≥60 years at the time of study registration (men and women eligible)
- Participants must have histologically or cytologically confirmed Stage I-III breast cancer with the following criteria met:
- If node-negative or if node status unknown (because it was not assessed), tumor must be >5 mm of any hormone receptor subtype (document ER/PR status: if some ER/PR staining is present, ER and PR negative are defined as being positive in <10% cells [per local pathology read]).
Key exclusion criteria (32 listed)
- Evidence of metastatic disease.
- Patients will not require baseline staging PET or CT chest, abdomen, pelvis or bone scan to rule out metastatic disease prior to enrollment. Any staging scans will be ordered at the treating provider's discretion. If metastatic disease is found on any staging studies done, patients will not be eligible for enrollment.
- Locally advanced tumors at diagnosis (T4), including tumors fixed to the chest wall, peau d'orange, skin ulcerations/nodules, or clinical inflammatory changes (diffuse brawny cutaneous induration with an erysipeloid).
- Patients with stage III, HER2-negative cancer in the contralateral breast (see 3.1.6 above).
- Positive Hepatitis B (Hepatitis B surface antigen and antibody) and/or Hepatitis C (Hepatitis C antibody test) as indicated by serologies conducted ≤3 months prior to registration if liver function tests are outside of the normal institutional range.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| T-DM1Also: KadcylaT-DM1 is an antibody-drug conjugate; it is made up of an antibody (trastuzumab) linked to a cytotoxic drug, DM1 (chemotherapy). T-DM1 functions as a targeted cancer therapy because it targets HER2-positive breast cancer cells directly, limiting exposure of the rest of the body to chemotherapy. | Drug | T-DM1 |
Primary outcome
Invasive Disease-free Survival Rate (IDFS)
Time frame: 5 years
IDFS is defined as the time from the first T-DM1 dose to ipsilateral invasive breast cancer recurrence, regional invasive breast cancer recurrence, distant recurrence, death due to any cause, contralateral invasive breast cancer, or a second non-breast primary cancer, whichever occurs first. Patients without one of these events at the time of data analysis will be censored at the date last known to be alive and event-free. Survival probabilities (reported as percentages) are estimated from Kaplan Meier methods.
8 secondary outcomes
Invasive Breast Cancer-free Survival (IBCFS)
Time frame: 5 years
Recurrence-free Interval (RFI)
Time frame: 5 years
Overall Survival (OS)
Time frame: 5 years
Site of First Recurrence
Time frame: 5 years
Incidence Rate of All Toxicities (Safety)
Time frame: 2 years
Incidence Rate of Cardiac-Related Adverse Events: Left Ventricular Systolic Dysfunction
Time frame: 2 years
Incidence Rate of Cardiac-Related Adverse Events: Cardiac Death
Time frame: 2 years
Incidence Rate of Cardiac-Related Adverse Events: Decreased Ejection Fraction
Time frame: 2 years
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Rachel Freedman, MD MPH principal investigator
Dana-Farber Cancer Institute
14 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing T-DM1 in people with Breast Cancer, run by Dana-Farber Cancer Institute at 14 sites in United States.
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 31 inclusion and 32 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: under way, not looking for participants, as of the sponsor's last update on 18 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 14 sites in United States. 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?
Yes. Results are posted in the registry (first posted 29 Apr 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Invasive Disease-free Survival Rate (IDFS) (time frame: 5 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 18 May 2026.