Real-World Outcomes of Patients With Metastatic Breast Cancer After Treatment With First-Line ET+CDK4/6i

Daiichi Sankyo

Status: Completed

Conditions: Advanced/Metastatic HER2-negative Breast Cancer

Treatments: Other: No drug

Study type: Observational

Funder types: Industry

Identifiers

NCT06975371

U31402-0012-NIS-MA

Details and patient eligibility

About

This study aims to assess the treatment patterns and real-world outcomes of HR+/HER- metastatic breast cancer patients who have progressed on 1L ET + CDK4/6i and started a second line (2L) treatment within a real-world cohort in the United States Flatiron Health Database.

Full description

This analysis will assess real-world outcomes in HR+/HER2- mBC patients who initiated a subsequent line of therapy (LOT) (i.e., 2L) after progressing on 1L treatment with ET+CDK4/6i. This study will also characterize the treatment patterns, clinical characteristics, and outcomes in this patient population. No study drug was administered in this non-interventional study.

Enrollment: 1,415 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion criteria

• Patients with evidence of Stage IV or recurrent mBC with a metastatic diagnosis date on or after January 1, 2017
• Aged ≥18 years at mBC diagnosis date
• Received 1L ET + CDK 4/6i, with no other systemic agents, in the metastatic setting
• Had evidence of a rwP event during 1L ET + CDK 4/6i
• Evidence of a subsequent LOT following 1L ET + CDK 4/6i (start date of subsequent LOT = index treatment date)
• A record of HR+ status in the closest estrogen receptor (ER) or progesterone receptor (PR) test result occurring prior to or within 30 days after the index treatment date
• A record of HER2- status in the closest HER2 test result recorded prior to or on the index treatment date
• Index treatment date occurring at least 90 days prior to end of study period (30Sep2024)

Exclusion Criteria

• A record of estrogen receptor 1 (ESR1), phosphatidylinositol4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), V-akt murine thymoma viral oncogene homolog (AKT1), phosphatase and tensin homolog (PTEN), or germline breast cancer gene (gBRCA) alteration/mutation prior to or within 30 days after index treatment date

Trial design

1,415 participants in 1 patient group

HR+/HER2- metastatic breast cancer

Description:

Adults in the Flatiron database who are diagnosed with HR+/HER2- metastatic breast cancer and initiated a subsequent line of therapy (i.e., 2L) after progressing on 1L treatment with ET+CDK4/6i.

Treatment:

Other: No drug