Clinical trial NCT06928818: Trastuzumab Emtansine(T-DM1) After Trastuzumab Deruxtecan(T-DXd) in HER2-Positive Breast Cancer in Korea
Official title: 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
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Cancer of Breast
Trastuzumab Emtansine
Trastuzumab Deruxtecan
Lead sponsor: Seoul National University Hospital
Sponsor class: OTHER
First posted: 2025-04-15
Enrollment: 100
Sex: ALL
Minimum age (years): 19
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: * Signed Informed Consent Form, when the patient is alive and not lost to follow- up.
* Age ≥ 19 years old.
* Histologically or cytologically confirmed, HER2-positive advanced breast cancer which is either locally advanced precluding resection or metastatic.
* Prior treatment with T-Dxd in the advanced setting
* Intention to treat with T-DM1 as next therapy upon progression from T-Dxd

Patients who meet any of the following criteria will be excluded from study entry:

* Any systemic treatment, other than T-DM1, for breast cancer after T-Dxd (With an exception, 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

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


Eligibility 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).

Primary outcomes:
measure: progression-free survival (PFS)
timeFrame: 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.
Secondary outcomes:
measure: objective response rate (ORR)
timeFrame: 12-month
measure: 12-month survival rate
timeFrame: 12-month
measure: time-to-discontinuation (TTD)
timeFrame: 12-month
measure: time-to-next-line-treatment (TTNT)
timeFrame: 12-month
measure: Duration of therapy (DoT)
timeFrame: 12-month
measure: Incidence of Treatment-Emergent Adverse Events
timeFrame: 12-month
Other outcomes:
Locations:
city: Seoul
country: Korea, Republic of
facility: Seoul National University Hospital
Study officials:
References: