Real-world Outcomes of Patients With HER2+ Metastatic Breast Cancer After Treatment With Trastuzumab Deruxtecan

Daiichi Sankyo228 enrolled

Overview

This study will explore treatment patterns and clinical outcomes using the US-based Flatiron Health database to describe patients with HER2+ mBC who were previously treated with T-DXd to better characterize this population and inform internal decision making in this rapidly changing therapeutic landscape.

This study will utilize a longitudinal, demographically and geographically diverse database derived from Electronic Health Record data. No study medication will be supplied or administered for this protocol. The primary research objective is to describe the real-world progression-free survival (rwPFS) in HER2+ mBC patients who initiated a subsequent line of therapy (LOT) after a T-DXd-containing LOT in the metastatic setting. Secondary research objectives include describing the real-world overall survival (rwOS), patient demographics and clinical characteristics, real-world time to next treatment (rwTTNT), and real-world time to treatment discontinuation (rwTTD) in HER2+ mBC patients who initiated a subsequent LOT after a T-DXd-containing LOT in the metastatic setting. Treatment patterns and sequencing in HER2+ mBC patients for subsequent LOTs following initial treatment with T-DXd will also be assessed.

Study Type

OBSERVATIONAL

Enrollment

228

Conditions

HER2-positive Breast Cancer

Interventions

No drugOTHER

This is an non-interventional, observational study. No drug will be provided or administered as part of this protocol.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria Patients must meet all the inclusion criteria below to be included in the study population: 1. Patients with evidence of stage IV or recurrent mBC with a metastatic diagnosis date on or after January 1, 2011. 2. Patients aged ≥18 years old at mBC diagnosis date. 3. Patients with ≥1 T-DXd-containing LOT in the metastatic setting. 4. Patients with evidence of a subsequent LOT following the first T-DXd-containing LOT in the metastatic setting. The LOT subsequent to the first T-DXd-containing LOT in the metastatic setting will be the index LOT. Index date will be the index LOT start date. 5. Patients whose closest HER2 test result (defined as immunohistochemistry \[IHC\] 3+ or in situ hybridization \[ISH\]+) recorded prior to or on the index date was a HER2+ test result. 6. Patients with index date occurring at least 90 days prior to end of study period (March 31st, 2024). Exclusion Criteria No exclusion criteria will be imposed.

Locations (1)

Flatiron Health, Inc

New York, New York, United States

Outcomes

Primary Outcomes

Real-world Progression-free Survival (rwPFS)

rwPFS is defined as the interval in months between the index date until the first evidence of progression or death as documented by Flatiron.

Time frame: Index date (index LOT start date) to date of earliest disease progression >14 days after the index date or date of death, whichever occurs first, up to approximately 13 years 3 months

Secondary Outcomes

Real-world Time to Next Treatment (rwTTNT)

rwTTNT is defined as the time in months between index date and initiation of next LOT, or death, whichever occurs first.

Time frame: Index date (index LOT start date) to next LOT start date or, in the absence of next LOT, death, whichever occurs first, up to approximately 13 years 3 months

Real-world Time to Treatment Discontinuation (rwTTD)

rwTTD is defined as the time in months between index date and date of treatment discontinuation or death, whichever occurs first.

Time frame: Index date (index LOT start date) to date treatment is discontinued, up to approximately 13 years 3 months

Treatment Patterns by Type of Line of Therapy

Treatment patterns will be described by LOT (monotherapy, combination therapy, and treatment sequence).

Time frame: Index date (index LOT start date) to end of study period, up to approximately 13 years 3 months

Data from ClinicalTrials.gov

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