NCT05950945 · Daiichi Sankyo
Trastuzumab Deruxtecan (T-DXd) in Patients Who Have Hormone Receptor-negative and Hormone Receptor-positive HER2-low or HER2 IHC 0 Metastatic Breast Cancer
What this study is about
This study will evaluate the safety and effectiveness of trastuzumab deruxtecan (T-DXd) in participants with human epidermal growth factor receptor 2 (HER2)-low or HER2 immunohistochemistry (IHC) 0 (who are both hormone receptor \[HR\]-negative and HR-positive) unresectable and/or metastatic breast cancer.
View original scientific description
This study will evaluate the safety and efficacy of trastuzumab deruxtecan (T-DXd) in participants with human epidermal growth factor receptor 2 (HER2)-low or HER2 immunohistochemistry (IHC) 0 (who are both hormone receptor \[HR\]-negative and HR-positive) unresectable and/or metastatic breast cancer.
Interventions
DRUG
Trastuzumab Deruxtecan
Intravenous administration, 5.4 mg/kg on Day 1 of each 21-day cycle until radiographic disease progression as assessed by the investigator, unacceptable toxicity, other discontinuation criteria are met, or 2 years after first dose of study drug
Primary outcome measures
Time From the Start of T-DXd to Initiation of Subsequent Anticancer Treatment (TTNT)
Time frame: Until subsequent therapy or death, assessed up to 24 months
TTNT is defined as the time interval from the date of first dose of T-DXd to the initiation of the next anticancer treatment or death due to any cause.
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
- Sign and date the main informed consent form
- Must agree to provide a newly obtained or archival baseline biopsy from primary and/or metastatic lesion.
- Pathologically documented Breast Cancer (BC) tumor
- Is unresectable and/or metastatic.
- Is hormone receptor-negative or hormone receptor-positive.
- Must include percentage of positively stained cells to characterize if hormone receptor-positive or -negative.
- Has confirmed HER2 IHC 1+ or IHC 2+/ISH- (HER2-low) status or HER2 IHC 0 status as determined according to ASCO CAP 2018 guidelines1 based on sample collected during Tissue Screening as described above.
- Was never previously HER2-positive (IHC 3+ or IHC 2+/ISH+) on prior pathology testing (per ASCO CAP guidelines).
- Was never previously treated with anti-HER2 therapy in the metastatic setting.
- Has had at least one and up to two prior lines of therapy in the metastatic setting.
- In participants with hormone receptor-positive HER2
Where
- Miami Beach, Florida
- Tampa, Florida
- Boston, Massachusetts
- Burlington, Massachusetts
- Summit, New Jersey
Collaborators
AstraZeneca
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 Jun 12, 2026 · Source of record for eligibility and locations