Real-World Treatment of ADC-Resistant HER2-Low Advanced Breast Cancer

NCT07587983 | Completed

• 1 other identifier: 2026-SR-247
• Study Type: observational
• Target: 220
• Locations: 1 country
• Sites: 1

Brief Summary

This is a multicenter, retrospective real-world study aiming to evaluate the efficacy and safety of post-antibody-drug conjugate (post-ADC) treatment strategies in patients with HER2-low advanced breast cancer who have developed resistance to prior ADC therapy. The study plans to enroll approximately 220 eligible patients from three centers in China (Jiangsu Province Hospital, Nanjing Drum Tower Hospital, and Nanjing General Hospital of Nanjing Military Command) between January 2018 and December 2025. Key efficacy outcomes include progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and clinical benefit rate (CBR). Safety outcomes include the incidence of grade 3/4 adverse events and serious adverse events. Subgroup analyses will compare different post-ADC regimens (e.g., alternative ADC, chemotherapy, endocrine therapy, immunotherapy) and explore the impact of visceral metastasis and prior ADC treatment response on subsequent outcomes. This study seeks to identify optimal post-ADC treatment strategies and preferred patient populations for clinical benefit.

Conditions

Breast Cancer

Outcome Measures

Primary Outcomes (1)

• real-world (rwPFS) of post-ADC therapy

  the duration from the post-ADC treatment initiation to either disease progression or death from any cause, whichever came first

  up to 12 months.

Secondary Outcomes (3)

• objective response rate (ORR)

  at 12 weeks

• Clinical benefit rate (CBR) of post-ADC therapy

  at 12 weeks

• overall survival (OS) of post-ADC therapy

  up to 24 months

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Patients with histologically confirmed HER2-low advanced or metastatic breast cancer who received antibody-drug conjugate (ADC) therapy in the advanced setting and subsequently experienced disease progression.

You may qualify if:

• females aged ≥18 years.
• confirmed pathologic diagnosis of HER2-low MBC (defined as HER2 IHC 1+ or 2+ without gene amplification by FISH detection).
• patients had disease progression following ADC treatment in advanced setting and had undergone at least one available efficacy evaluation.
• patients received at least one subsequent anti-tumor treatment following ADC failure, with at least one available efficacy evaluation.

You may not qualify if:

• patients previously treated with ADC during neoadjuvant or adjuvant setting.
• patients who had not experienced disease progression on their first ADC (ADC1) regimen and remained on ADC1 treatment.
• patients with no documented subsequent anti-tumor therapy following ADC1 treatment.
• patients who lacked evaluable efficacy assessment data during ADC1 or post-ADC therapy.
• patients with incomplete clinicopathological information.

Sponsors & Collaborators

• The First Affiliated Hospital with Nanjing Medical University: lead

Study Sites (1)

The First Affiliated Hospital with Nanjing Medical University

Nanjing, Jiangsu, 210029, China

Location

MeSH Terms

Conditions

Breast Neoplasms

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 14, 2026
• First Posted: May 14, 2026
• Study Start: March 1, 2018
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: May 14, 2026

Record last verified: 2026-04

Locations

CN (1)