NCT04553770 · Jonsson Comprehensive Cancer Center
Trastuzumab Deruxtecan Alone or in Combination With Anastrozole for the Treatment of Early Stage HER2 Low, Hormone Receptor Positive Breast Cancer
What this study is about
This phase II trial investigates how well trastuzumab deruxtecan works alone or in combination with anastrozole in treating patients with HER2 low, hormone receptor positive breast cancer. Trastuzumab deruxtecan is a monoclonal antibody, called trastuzumab, linked to a chemotherapy drug called deruxtecan.
View original scientific description
This phase II trial investigates how well trastuzumab deruxtecan works alone or in combination with anastrozole in treating patients with HER2 low, hormone receptor positive breast cancer. Trastuzumab deruxtecan is a monoclonal antibody, called trastuzumab, linked to a chemotherapy drug called deruxtecan. Trastuzumab attaches to HER2 expressed at low levels on cancer cells in a targeted way and delivers deruxtecan to kill them.
Interventions
DRUG
Anastrozole
Given PO
PROCEDURE
Therapeutic Conventional Surgery
Undergo surgery
BIOLOGICAL
Trastuzumab Deruxtecan
Given IV
Primary outcome measures
Pathologic complete response (pCR) rate
Time frame: Baseline to surgery
pCR is defined as the absence of invasive cancer in the breast and sampled regional lymph nodes. pCR will be calculated along with the corresponding exact 95% Clopper-Pearson confidence interval (CI).
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
- Previously untreated operable invasive carcinoma of the breast greater than 2.0 cm (cT2) in size based on physical exam or imaging. Patients with clinical node negative disease or clinical node (cN1/cN2) positive are allowed provided they are deemed to have operable disease at study entry
- Participants with clinically involved lymph nodes should not have radiological evidence of distant disease per standard of care staging prior to patient informed consent form (PICF) signature
- In the United States
- Tumor is HER2-low by immunohistochemistry (IHC), defined as 1+ or 2+, confirmed by central testing (central testing results not required for enrollment, unless no local results available). If HER2 is 2+ by IHC, fluorescence in situ hybridization (FISH) must be performed (per standard of care) and the FISH result must be HER2 non-amplified per 2018 American Society of Clinical Oncology College of American Pathologists (ASCO CAP) guidelines
- Tumor is HR positive (H
Where
- Fullerton, California
- Los Alamitos, California
- Los Angeles, California
- Torrance, California
- Whittier, California
- Orlando, Florida
- Fort Wayne, Indiana
- Wichita, Kansas
- Boston, Massachusetts
Collaborators
Translational Research in Oncology, Daiichi Sankyo Co., Ltd.
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 Nov 10, 2025 · Source of record for eligibility and locations