RecruitingObservational

HER2 Heterogeneity and Its Impact on Benefit From Trastuzumab Deruxtecan in Metastatic Breast Cancer

NCT ID: NCT06551220Sponsor: Sun Yat-sen UniversityLast updated: 2026-05-22

Summary

The purpose of this observational study is to learn about the HER2 heterogeneity and its impact on benefit from trastuzumab deruxtecan in metastatic breast cancer. The main question it aims to answer is: \- Does the heterogeneity of HER2 expression level and spatial distribution in different tissues affect the efficacy of trastuzumab deruxtecan in metastatic breast cancer?

Arms & interventions

DrugTrastuzumab Deruxtecan
The patients received Trastuzumab Deruxtecan at a dose of 5.4 mg/kg every 3 weeks until disease progression or unacceptable adverse effects occurred.

Outcome measures

Primary

Progression-free survival (PFS)
Progression-free survival (PFS) is defined as the time from T-DXd treatment initiation to disease progression or death from any cause.
Time frame: From date of T-DXd treatment initiation until the date of first documented disease progression or date of death from any cause, whichever came first, assessed up to 60 months.

Secondary

Overall survival (OS)
Time frame: From date of T-DXd treatment initiation until the date of death from any cause, assessed up to 60 months.

Eligibility criteria

Sex: FemaleAge: 18 Years to 80 YearsHealthy volunteers: No

Inclusion Criteria: * Patients with advanced or locally unresectable breast cancer; * Treated with T-DXd (DS-8201, trastuzumab deruxtecan) regardless of line of therapy, HR, and HER2 expression level; * HER2 immunohistochemistry staining information of the primary lesion or metastatic/recurrent lesion; * Measurable lesions with treatment response results that can be evaluated through imaging examinations; * Able to follow up with the latest progression-free survival or overall survival. Exclusion Criteria: * Patients with missing basic clinical information or HER2 immunohistochemistry staining information; * Patients with missing pathological results for both primary and metastatic/recurrent lesions; * Patients with no measurable lesions and unable to evaluate T-DXd treatment response; * Discontinue T-DXd therapy for unacceptable adverse events or other reasons; * Patients lost to follow-up after T-DXd treatment.

Study locations (2)

Yale Cancer Center

New Haven, Connecticut, 06510

Recruiting

Amin H. Nassar, MD · Contact

amin.nassar@yale.edu

Dana-Farber Cancer Institute, Harvard Medical School

Boston, Massachusetts, 02215

Recruiting

Paolo Tarantino, MD, PhD · Contact

Paolo_Tarantino@DFCI.HARVARD.EDU