Clinical trial NCT06975371: Real-World Outcomes of Patients With Metastatic Breast Cancer After Treatment With First-Line ET+CDK4/6i
Official title: Real-World Outcomes of Patients With HR-Positive HER2-Negative Metastatic Breast Cancer After Treatment With First-Line ET+CDK4/6i in the United States
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Advanced/Metastatic HER2-negative Breast Cancer
Keywords: HR-positive
HER2-negative
Metastatic breast cancer
Lead sponsor: Daiichi Sankyo
Sponsor class: INDUSTRY
First posted: 2025-05-16
Enrollment: 2200
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The study cohort consists of adults in the Flatiron database who are diagnosed with HR+/HER2- mBC and initiated a subsequent LOT (i.e., 2L) after progressing on 1L treatment with ET+CDK4/6i.

Brief summary: 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.

Detailed 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.

Eligibility 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

Primary outcomes:
measure: Real-world progression-free survival (rwPFS)
timeFrame: Baseline up to end of observation period, approximately 7 years 9 months
Secondary outcomes:
measure: Real-world overall survival (rwOS)
timeFrame: Baseline up to end of observation period, approximately 7 years 9 months
measure: Real-world time to discontinuation or death (rwTTD/D)
timeFrame: Baseline up to end of observation period, approximately 7 years 9 months
measure: Real-world time to next treatment or death (rwTTNT/D)
timeFrame: Baseline up to end of observation period, approximately 7 years 9 months
Other outcomes:
Locations:
city: New York
country: United States
facility: Flatiron Health, Inc
state: New York
Study officials:
affiliation: Daiichi Sankyo
name: Director
role: STUDY_DIRECTOR
References: