Trastuzumab Emtansine(T-DM1) After Trastuzumab Deruxtecan(T-DXd) in HER2-Positive Breast Cancer in Korea

Recruiting

• Conditions: Cancer of Breast; Trastuzumab Emtansine; Trastuzumab Deruxtecan

• Registration Number: NCT06928818
• Lead Sponsor: Seoul National University Hospital

Brief Summary

Prospective observational study of trastuzumab emtansine immediately after trastuzumab deruxtecan in patients with advanced HER2-positive breast cancer in Korea

Detailed Description

Not available

Study Timeline

• Study Start: 2025-02-26
• Status Verified: 2025-03
• Study First Submitted: 2025-03-31
• Study First Submitted QC: 2025-04-07
• Last Update Submitted: 2025-04-14
• Study First Posted: 2025-04-15
• Last Update Posted: 2025-04-17
• Primary Completion: 2028-09-30
• Study Completion: 2029-09-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 100

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).

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
progression-free survival (PFS)	PFS is defined as the time from treatment initiation to the first occurrence of disease progression or death from any cause, whichever occurs first, assessed up to 12 months.	PFS will be assessed by physicians as per routine clinical practice. CT and/or MRI scans will be at baseline and every 2-4 cycles at the treating physician's discretion, reflecting the observational study design.

Secondary Outcome Measures

Name	Time	Method
objective response rate (ORR)	12-month	• objective response rate (ORR)
12-month survival rate	12-month	12-month survival rate
time-to-discontinuation (TTD)	12-month	time-to-discontinuation (TTD)
time-to-next-line-treatment (TTNT)	12-month	time-to-next-line-treatment (TTNT), disregarding endocrine treatments as the maintenance
Duration of therapy (DoT)	12-month	Duration of therapy (of T-DM1) will be compared to the duration of previous therapy (T-DXd) to ensure the comparability of each treatments reflecting the tumor biology and clinical course.
Incidence of Treatment-Emergent Adverse Events	12-month	Incidence of Treatment-Emergent Adverse Events

Trial Locations

Locations (1)

Seoul National University Hospital; 🇰🇷 Seoul, Korea, Republic of