Exploring outcomes in patients with HER2-positive metastatic breast cancer after treatment with Trastuzumab Deruxtecan

Real-world Outcomes of Patients With HER2-positive (HER2+) Metastatic Breast Cancer (mBC) After Treatment With Trastuzumab Deruxtecan (T-DXd) in the United States

Observational Daiichi Sankyo · NCT06833268

This study looks at how well Trastuzumab Deruxtecan works for people with HER2-positive metastatic breast cancer and what happens to them after they start a new treatment.

Quick facts

Study typeObservational
Enrollment220 (estimated)
Ages18 Years and up
SexAll
SponsorDaiichi Sankyo Industry-sponsored
Locations1 site (New York, New York)
Trial IDNCT06833268 on ClinicalTrials.gov

What this trial studies

This observational study aims to analyze treatment patterns and clinical outcomes for patients with HER2-positive metastatic breast cancer who have been treated with Trastuzumab Deruxtecan (T-DXd). Utilizing the Flatiron Health database, the study will assess real-world progression-free survival, overall survival, and other treatment-related metrics in this patient population. The research will focus on patients who have initiated a subsequent line of therapy after their initial T-DXd treatment, providing insights into the effectiveness and sequencing of treatments in a real-world setting.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 and older with stage IV or recurrent HER2-positive metastatic breast cancer who have received at least one line of therapy containing T-DXd.

Not a fit: Patients who have not received T-DXd or do not have HER2-positive breast cancer may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide valuable insights into the effectiveness of treatment strategies for HER2-positive metastatic breast cancer, potentially improving patient outcomes.

How similar studies have performed: Other studies have shown success in analyzing real-world outcomes in cancer treatment, suggesting that this approach is both relevant and potentially impactful.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria

Patients must meet all the inclusion criteria below to be included in the study population:

1. Patients with evidence of stage IV or recurrent mBC with a metastatic diagnosis date on or after January 1, 2011.
2. Patients aged ≥18 years old at mBC diagnosis date.
3. Patients with ≥1 T-DXd-containing LOT in the metastatic setting.
4. Patients with evidence of a subsequent LOT following the first T-DXd-containing LOT in the metastatic setting. The LOT subsequent to the first T-DXd-containing LOT in the metastatic setting will be the index LOT. Index date will be the index LOT start date.
5. Patients whose closest HER2 test result (defined as immunohistochemistry \[IHC\] 3+ or in situ hybridization \[ISH\]+) recorded prior to or on the index date was a HER2+ test result.
6. Patients with index date occurring at least 90 days prior to end of study period (March 31st, 2024).

Exclusion Criteria No exclusion criteria will be imposed.

Where this trial is running

New York, New York

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions HER2-positive Breast CancerHER2-positive breast cancerReal-world outcomes
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.