A Retrospective Cohort Study of T-DXd administration in HER2-Positive, Low-Expressing Advanced Breast Cancer Patients with History of Interstitial Lung Disease.

A Chart Review Study of T-DXd following ILD in HER2+/ HER2-Low Breast Cancer Patients - A retrospective study on the administration of T-DXd in patients with a history of interstitial lung disease.

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

JPRN

Registry ID

JPRN-UMIN000057601

Enrollment

Registered

2025-06-15

Start date

2025-12-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

advanced recurrent breast cancer

Interventions

None listed

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: Cohort 1: 1. Patients diagnosed with HER2 positive (IHC3+ or IHC2+ ISH+) or low HER2 expression (IHC1+ or IHC2+ ISH-) advanced or metastatic breast cancer. 2. Patients who received T-DXd and had ILD of Grade1* history by T-DXd. *Asymptomatic steroidal cases are included in Grade1 3. Patients who started T-DXd retreatment between December 2022 and June 2025 after ILD recovery, with or without other breast cancer medications prior to T-DXd retreatment. 4. Patients who can provide CT scan images for central review. Cohort 2: 1. Patients diagnosed with HER2 positive (IHC 3+ or IHC2+ ISH+) or low HER2 expression (IHC1+ or IHC2+ ISH-) advanced or metastatic breast cancer. 2. Patients with a history of ILD (with any Grade) by anticancer drugs other than T-DXd (endocrine therapy, molecular targeted agents, chemotherapy, ADC other than T-DXd) 3. Patients who started T-DXd treatment between December 2021 and June 2025 after ILD recovery. 4. Patients who can provide CT scan images for central review.

Exclusion criteria

Exclusion criteria: Cohort 1, 2: 1. Patients with a history or complications of radiotherapy induced radiological ILD requiring interventional treatment 2. Patients with a history or complications of idiopathic ILD

Design outcomes

Primary

Measure	Time frame
Ratio of recurrent ILD, Grade of recurrent ILD Definition of ILD recurrence: Worsening of the ILD grade at the time of the re-administration of T-DXd (Cohort 1), compared to the initial administration of T-DXd (Cohort 2).	—

Secondary

Measure	Time frame
Ratio of recurrent ILD, Grade of recurrent ILD(investigator assessment) TTF(Time to Treatment Failure) PFS(progression-free survival) TTP(time to progression)	—

Countries

Japan

Contacts

Public ContactMichiko Harao

Jichi Medical University Department of Surgery, Division of Gastroenterological, General and Transplant Surgery

miharao@jichi.ac.jp0285-58-7371

Outcome results