Real-world Treatment Patterns of Endocrine Based Therapy Among Patients With Hormone Receptor-positive/Human Epidermal Growth Factor Receptor-2-negative (HR+/HER2-) Advanced Breast Cancer: An Analysis of Administrative Claims Data in Japan

Descriptive Analyses of Clinical Characteristics and Treatment Patterns of Breast Cancer Patients Initiating Palbociclib (Ibrance(Registered)) Treatment in Japan by Using MDV Database

This is a retrospective observational study focusing on patients diagnosed with advanced breast cancer(ABC) in Japan using de-identified claim data from Medical Data Vision (MDV) database.

The primary objective of this study is to describe patient demographics, treatment patterns and treatment duration of palbociclib, and subsequent treatment patterns and treatment duration after palbociclib-based therapy among ABC patients in Japan The secondary objective of the study is to describe patient demographics, treatment patterns of ABC patients and treatment duration of endocrine therapy, and subsequent treatment patterns and treatment duration after endocrine therapy among ABC patients in Japan.

Study Overview

• Status: Completed
• Conditions: Breast Cancer

• Study Type: Observational
• Enrollment (Actual): 1170

Contacts and Locations

Study Locations

• Japan
  • Tokyo, Japan
    • Pfizer Japan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Japanese patients with diagnosis of breast cancer, diagnosis of secondary malignant neoplasm and who received endocrine therapy drugs and who didn't receive anti-HER2 therapy drugs (defined as HR+/HER2- breast cancer) and whose data were registered into the MDV database from April 2008

Description

Inclusion Criteria:

• Diagnosis of breast cancer based on International statistical classification of diseases and related health problems 10th revision (International Statistical Classification of Diseases and Related Health Problems [ICD-10]) (C50.xx)
• Received at least one prescription of endocrine therapy drugs
• Diagnosis of secondary malignant neoplasm based on ICD-10 (C77.x, C78.x, C79.x )

Exclusion Criteria:

-Received a prescription of anti-HER2 therapy (Trastuzumab, Trastuzumab emtansine, Pertuzumab, and Lapatinib tosilate hydrate)

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Patients with HR+/HER2- advanced breast cancer

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants According to Number of Blood Tests at 1 to 4 Weeks From Palbociclib Treatment Initiation	Percentage of participants according to number of blood tests (0, 1, 2, 3, 4 and >=5) at 1 to 4 weeks after administration of palbociclib is reported in this outcome measure.	Anytime between 1 to 4 weeks from palbociclib treatment initiation; available data observed retrospectively over approximately 22 months in this study
Percentage of Participants According to Number of Blood Tests at 5 to 8 Weeks From Palbociclib Treatment Initiation	Percentage of participants according to number of blood tests (0, 1, 2, 3, 4 and >=5) at 5 to 8 weeks after administration of palbociclib is reported in this outcome measure.	Anytime between 5 to 8 weeks from palbociclib treatment initiation; available data observed retrospectively over approximately 22 months in this study
Percentage of Participants According to Number of Blood Tests at 9 to 12 Weeks From Palbociclib Treatment Initiation	Percentage of participants according to number of blood tests (0, 1, 2, 3, 4 and >=5) at 9 to 12 weeks after administration of palbociclib is reported in this outcome measure.	Anytime between 9 to 12 weeks from palbociclib treatment initiation; available data observed retrospectively over approximately 22 months in this study
Percentage of Participants According to Number of Blood Tests at 13 to 16 Weeks From Palbociclib Treatment Initiation	Percentage of participants according to number of blood tests (0, 1, 2, 3, 4 and >=5) at 13 to 16 weeks after administration of palbociclib is reported in this outcome measure.	Anytime between 13 to 16 weeks from palbociclib treatment initiation; available data observed retrospectively over approximately 22 months in this study
Percentage of Participants According to Number of Blood Tests at 17 to 20 Weeks From Palbociclib Treatment Initiation	Percentage of participants according to number of blood tests (0, 1, 2, 3, 4 and >=5) at 17 to 20 weeks after administration of palbociclib is reported in this outcome measure.	Anytime between 17 to 20 weeks from palbociclib treatment initiation; available data observed retrospectively over approximately 22 months in this study
Time to Treatment Failure of Palbociclib	Time to treatment failure of palbociclib was defined as time from the date of first palbociclib prescription to the date of lost to follow-up or to the date of the next line of therapy, defined as the end of palbociclib treatment. Time to treatment failure of palbociclib was censored at participant disenrollment or end of study period.	From start of palbociclib treatment until end of palbociclib treatment or censoring date (maximum up to 42.5 months); available data observed retrospectively over approximately 22 months in this study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Palbociclib Daily Dose		From start of palbociclib treatment until end of palbociclib treatment or end of study period (maximum up to 42.5 months); available data observed retrospectively over approximately 22 months in this study
Number of Participants According to Regimen of First Subsequent Therapy After End of Palbociclib	Number of participants according to regimen of first subsequent therapy after end of palbociclib at first line and second line are reported in this outcome measure. The regimen was defined as any breast cancer treatment(s) received within 30 days of earlier treatment initiation. Only regimens used by >=3 participants in participants treated with palbociclib in the first or second line settings were reported. One participant may be included in more than one regimen.	From first subsequent therapy until end of study period (maximum up to 38.1 months); available data observed retrospectively over approximately 22 months in this study
Time to Treatment Failure of Subsequent Therapy After End of Palbociclib	Time to treatment failure of subsequent therapy after palbociclib was defined as time from the date of first next line of therapy after end of palbociclib treatment to the date of lost to follow-up or to the date of the second next line of therapy. Time to treatment failure was censored at participant disenrollment or end of study period.	From start of first subsequent therapy until date of lost to follow-up or date of next line of therapy or censoring date (maximum up to 38.1 months); available data observed retrospectively over approximately 22 months in this study

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body Mass Index (BMI) at Palbociclib Initiation	BMI was calculated using the formula: BMI=(weight)/(height/100)^2.	At palbociclib initiation; available data observed retrospectively over approximately 22 months in this study
Charlson Comorbidity Index at Palbociclib Initiation	Charlson Comorbidity Index predicts the ten-year mortality for a participant who may have a range of comorbid conditions. 17 comorbidities were assessed with associated weights from 1 to 6, based on the adjusted risk of mortality. The total score is derived by summing up the weights of comorbid conditions presented. The minimum score value is 0 and maximum is 37. A higher score means a greater mortality risk.	At palbociclib initiation; available data observed retrospectively over approximately 22 months in this study
Number of Participants According to Index Year for Palbociclib Initiation	Index year was considered as the year corresponding to the start date of the first palbociclib line. Number of participants according to index year (2017, 2018, 2019, 2020, 2021) are reported in this outcome measure.	Palbociclib initiation in 2017, 2018, 2019, 2020, 2021; available data observed retrospectively over approximately 22 months in this study
Percentage of Participants According to Type of First Subsequent Breast Cancer Treatment After End of Palbociclib as First Line	One participant may be included in more than one breast cancer treatment.	From first subsequent therapy until end of study period (maximum up to 38.1 months); available data observed retrospectively over approximately 22 months in this study
Number of Participants With Antibiotic Use During Palbociclib Treatment		From start of palbociclib treatment until end of palbociclib treatment or end of study period (maximum up to 42.5 months); available data observed retrospectively over approximately 22 months in this study
Number of Participants With Granulocyte-Colony Stimulating Factor (G-CSF) Use During Palbociclib Treatment		From start of palbociclib treatment until end of palbociclib treatment or end of study period (maximum up to 42.5 months); available data observed retrospectively over approximately 22 months in this study
Number of Participants According to Type of Endocrine Therapy Combined With Palbociclib	Number of participants according to the type of endocrine therapy (fulvestrant, letrozole, exemestane, anastrozole, tamoxifen, toremifen and other) combined with palbociclib at first line, second line and third line is reported in this outcome measure. "Other" included participants prescribed >=1 endocrine therapies and those prescribed medroxyprogesterone.	From start of palbociclib treatment until end of palbociclib treatment or end of study period (maximum up to 42.5 months); available data observed retrospectively over approximately 22 months in this study

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): August 31, 2019
• Primary Completion (Actual): June 30, 2021
• Study Completion (Actual): June 30, 2021

Study Registration Dates

• First Submitted: November 29, 2021
• First Submitted That Met QC Criteria: November 29, 2021
• First Posted (Actual): December 10, 2021

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: March 29, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Advanced breast cancer; Hormone receptor positive (HR+); Human Epidermal Growth Factor Receptor 2 Negative (HER2-)
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms
• Other Study ID Numbers: A5481115; NCT05153187 (Registry Identifier: ClinicalTrials.gov)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.