Real-World Treatment Patterns and Outcomes in HER2-Altered Metastatic Breast Cancer Patients in the United States

NCT ID: NCT07342309

Last Updated: 2026-01-15

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Total Enrollment: 7933 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2026-01-12
• Study Completion Date: 2026-06-30

Brief Summary

This study aims to address the following key objectives in patients with HER2-altered mBC:

Primary objectives

• Estimate the prevalence of human epidermal growth factor receptor 2 positive (HER2+), human epidermal growth factor receptor 2 (HER2) mutation, cooccurrence of HER2+ and HER2 mutation among adult patients with metastatic breast cancer (mBC)
• Among mBC patients with HER2+ and HER2 mutation, describe the following:

• Baseline demographic and clinical characteristics
• Treatment patterns during follow-up including 1L through fifth-line (5L) settings
• Real-world overall survival (rwOS) for 1L through 5L

Secondary objectives

• Among mBC patients with HER2+ and HER2 mutation, examine the following (as permissible in the study data):

• Real-world progression-free survival (rwPFS)
• Real-world time to discontinuation (rwTTD)
• Real-world time to next treatment (rwTTNT)
• Real-world overall response rate (rwORR)

Conditions

Metastatic Breast Cancer

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: RETROSPECTIVE

Study Groups

Metastatic breast cancer cohort (mBC)

Adult patients (\>=18 years) with confirmed diagnosis of recurrent or de novo metastatic breast cancer (mBC) who were diagnosed between January 1, 2018, through March 31, 2024 (1 year prior to the data cutoff date, March 31, 2025) in the Flatiron Solid Tumor Discovery Clinico-Genomic Database (CGDB).

No interventions assigned to this group

HER2-positive subcohort (mBC HER2+)

Patients meeting eligibility of the mBC cohort.

Evidence of HER2 positive (HER2+) as defined by immunohistochemistry (IHC)/in situ hybridization (ISH)

• IHC 3+ or
• IHC 2+ and evidence of HER2 amplification by ISH or
• ISH+ without further information on IHC.

No interventions assigned to this group

HER2-mutant subcohort (mBC HER2-mutant)

Patients meeting eligibility of the mBC cohort.

Evidence of NGS short variant alterations at any time in the database, regardless of the functional type, which includes missense, nonsense, frameshift, nonframeshift, or splice variants.

Patients who are not included in the HER2+ subcohort.

No interventions assigned to this group

Eligibility Criteria

Inclusion Criteria

Overall metastatic breast cancer (mBC) cohort (total population):

• Histologically or cytologically confirmed diagnosis of breast cancer (BC)
• Patient has at least 2 documented clinical visits in the Flatiron network, on different days, during the study period from 1 January 2011 through 31 March 2025
• Initial diagnosis of de novo or recurrent mBC established during the case selection window from 1 January 2018 through 31 March 2024 (1 year prior to the data cutoff date, 31 March 2025)

-- The date of initial mBC diagnosis will define the study index date

• Aged ≥ 18 years at the study index date

Human epidermal growth factor receptor 2 (HER2)-positive subcohort (mBC HER2+):

• Patients meeting eligibility for the mBC cohort
• Patients can be HER2-mutant or HER2 nonmutant
• Evidence of HER2+ as defined by immunohistochemistry (IHC)/in situ hybridization (ISH) based on a test performed within 180 days before or 180 days after the index date. If a patient does not have any IHC/ISH test during the 180-day periods before or after the index date, then tests performed at any time in the pre-index date period will be examined and any evidence of HER2+ status will classify the patient as HER2+.

• IHC 3+ or IHC 2+ and evidence of HER2 amplification by ISH or ISH+ (without further information on IHC) according to American Society of Clinical Oncology/College of American Pathologists guidelines.
• The sample date will be used to define biomarker status. If the sample date is missing, the report date will be used.

HER2-mutant subcohort (mBC HER2-mutant):

• Patients meeting eligibility for the mBC cohort
• HER2-mutant: Patients are classified as having an HER2 mutation if there is evidence of NGS short variant alterations at any time in the database, regardless of the functional type, which includes missense, nonsense, frameshift, nonframeshift, or splice variants.

Exclusion Criteria

mBC cohort (total population):

-To ensure adequate treatment and outcome data, any patient without a visit or medication record (i.e., medication order/administration or LOT) within 90 days of mBC diagnosis (i.e., the time window from 90 days before to 90 days after the mBC diagnosis).

HER2+ subcohort (mBC HER2+):

• None (other than those applicable for the mBC cohort).

HER2-mutant subcohort (mBC HER2-mutant):

• Patients who are included in the HER2+ subcohort.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Boehringer Ingelheim

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Ridgefield

Ridgefield, Connecticut, United States

Countries

United States

Central Contacts

Boehringer Ingelheim

Role: CONTACT

clintriage.rdg@boehringer-ingelheim.com

1-800-243-0127

Facility Contacts

Boehringer Ingelheim

Role: primary

unitedstates@bitrialsupport.com

833-602-2368

Related Links

https://www.mystudywindow.com

Related Info

Other Identifiers

1479-0045

Identifier Type: -

Identifier Source: org_study_id