Using Trastuzumab Emtansine after Trastuzumab Deruxtecan for HER2-Positive Breast Cancer

Prospective Observational Study of Trastuzumab Emtansine Immediately After Trastuzumab Deruxtecan in Patients With Advanced Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer in Korea

Observational Seoul National University Hospital · NCT06928818

This study is testing if giving trastuzumab emtansine right after trastuzumab deruxtecan helps people with advanced HER2-positive breast cancer who haven't responded to the first treatment.

Quick facts

Study typeObservational
Enrollment100 (estimated)
Ages19 Years and up
SexAll
SponsorSeoul National University Hospital Academic / other
Drugs / interventionstrastuzumab
Locations1 site (Seoul)
Trial IDNCT06928818 on ClinicalTrials.gov

What this trial studies

This observational study investigates the effectiveness of trastuzumab emtansine (T-DM1) administered immediately after trastuzumab deruxtecan (T-DXd) in patients with advanced HER2-positive breast cancer in Korea. The study aims to evaluate the outcomes of patients who have progressed on T-DXd and are treated with T-DM1 as their next line of therapy. Participants must have previously received T-DXd and meet specific eligibility criteria regarding their treatment history. The study will provide insights into the sequential use of these therapies in managing advanced breast cancer.

Who should consider this trial

Good fit: Ideal candidates are patients with HER2-positive, advanced breast cancer who have previously been treated with trastuzumab deruxtecan.

Not a fit: Patients who have received T-DM1 for advanced breast cancer or have undergone four or more lines of therapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could improve treatment outcomes for patients with advanced HER2-positive breast cancer.

How similar studies have performed: While this study follows a novel approach, similar studies have shown promise in sequential therapy for HER2-positive breast cancer.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* HER2-positive, advanced (unresectable locally advanced or metastatic) breast cancer
* Prior treatment with trastuzumab deruxtecan(T-DXd) in the advanced setting
* Intention to treat with Trastuzumab Emtansine (T-DM1) as first therapy upon T-DXd progression

Exclusion Criteria:

* Any systemic treatment, other than T-DM1, for breast cancer after trastuzumab deruxtecan (As an exception, patients treated with endocrine agents, not in combination with cytotoxics or antibody-drug conjugates, will be permitted in the study)
* Has been previously treated with T-DM1 for advanced breast cancer
* Has been previously treated with 4 or more lines of therapy for advanced breast cancer

  * Half (50%) or more patients will be those who were treated with second-line trastuzumab deruxtecan (i.e. patients at the later line will be capped).

Where this trial is running

Seoul

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 Cancer of BreastTrastuzumab EmtansineTrastuzumab Deruxtecan
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.