Study to Evaluate Real-world Effectiveness With Palbociclib Plus Endocrine Therapy as First-line/Second-line Treatment for HR+/HER2- Advanced Breast Cancer in Japan

Retrospective, Multicenter, Observational Study to Evaluate Real-World Effectiveness of Palbociclib Plus Endocrine Therapy in Japanese Patients With HR+/HER2- Advanced Breast Cancer in First Line or Second Line Settings

This is a retrospective, multicenter, observational study in Japan by medical record review of advanced breast cancer (ABC) patients who have received palbociclib plus endocrine therapy (ET) as first line or second line setting. For the purposes of this study, analyses will be descriptive in nature. No formal hypothesis testing is planned.

Study Overview

• Status: Completed
• Conditions: Breast Cancer
• Intervention / Treatment: Drug: Palbociclib; Drug: Endocrine therapy

• Study Type: Observational
• Enrollment (Actual): 693

Contacts and Locations

Study Locations

• Japan
  • Gifu, Japan, 501-1194
    • Gifu University Hospital
  • Hiroshima, Japan, 734-8551
    • Hiroshima University Hospital
  • Kanagawa, Japan, 259-1193
    • Tokai University Hospital
  • Nagoya, Japan, 464-8681
    • Aichi Cancer Center
  • Osaka, Japan, 540-0006
    • National Hospital Organization Osaka National Hospital
  • Shizuoka, Japan, 420-8527
    • Shizuoka Prefectural Hospital Organization
  • Tokyo, Japan, 142-8666
    • Showa University Hospital
  • Aichi-ken
    • Nagoya, Aichi-ken, Japan, 466-8560
      • Nagoya University Hospital
  • Ehime
    • Matsuyama, Ehime, Japan, 791-0280
      • National Hospital Organization Shikoku Cancer Center
  • Fukuoka
    • Kurume, Fukuoka, Japan, 830-0013
      • Japan Community Health care Organization Kurume General Hospital
  • Hokkaido
    • Sapporo, Hokkaido, Japan, 003-0804
      • Hokkaido Cancer Center
  • Ishikawa-ken
    • Kanazawa, Ishikawa-ken, Japan, 920-8530
      • Ishikawa Prefectural Central Hospital
  • Kanagawa
    • Sagamihara, Kanagawa, Japan, 252-0329
      • Kitasato University Hospital
  • Miyagi
    • Sendai, Miyagi, Japan, 980-8574
      • Tohoku University Hospital
  • Osaka
    • Kaizuka, Osaka, Japan, 597-0015
      • Kaizuka City Hospital
    • Osaka, Osaka, Japan, 541-8567
      • Osaka International Cancer Institute
    • Suita, Osaka, Japan, 565-0871
      • Osaka University Hospital
  • Saitama
    • Kita-adachi-gun, Saitama, Japan, 362-0806
      • Saitama Prefectural Cancer Center
  • Shizuoka
    • Hamamatsu, Shizuoka, Japan, 430-8558
      • Seirei Hamamatsu General Hospital
  • Tochigi
    • Shimotsuke, Tochigi, Japan, 329 0498
      • Jichi Medical University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This study uses secondary data of multiple sites by utilizing medical record review approach for those who have been diagnosed with ABC in Japan.

Description

Inclusion Criteria:

• Diagnosis of HR+/HER2- ABC
• Age of 20 years or older at diagnosis of ABC
• Patients that received palbociclib plus ET in the first line or second line
• Patients who meet the criteria regarding the medical record below:
• Patients with any medical records (regardless of palbociclib use) for more than 6 months from palbociclib initiation OR
• Patients with any medical records for less than 6 months from palbociclib initiation AND who had specific events (death, disease progression, or treatment discontinuation of palbociclib due to adverse events) in the available records

Exclusion Criteria:

• Patients who received chemotherapy as first line treatment.
• Patients who have previously participated or are participating in any interventional clinical trials that include investigational or marketed products.

(Interventional clinical trials for early breast cancer and later line after palbociclib will be acceptable, Besides, patients participating in other investigator-initiated research or noninterventional studies can be included as long as their standard of care is not altered by the study.)

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Real-World Progression-Free Survival (rwPFS) of palbociclib plus ET as first line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023
rePFS of palbociclib plus ET as second line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023

Secondary Outcome Measures

Outcome Measure	Time Frame
Landmark overall survival (OS) (defined from palbociclib initiation to death) of palbociclib plus ET as first line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023
Landmark OS (defined from palbociclib initiation to death)of palbociclib plus ET as second line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023
Landmark OS (defined from treatment initiation of first line to death) when palbociclib plus ET were used as second line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023
Time to treatment discontinuation (TTD) of palbociclib plus ET as first line or second line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023
TTD of first subsequent treatment for HR+/HER2- ABC patients who were treated with palbociclib plus ET	15 December 2017 to 31 August 2023
Time to chemotherapy (TTC: defined as the time from treatment initiation of first or second line for HR+/HER2- ABC to first use of chemotherapy)	15 December 2017 to 31 August 2023
Real-world objective response rate (rwORR) of palbociclib plus ET as first line or second line treatment for HR+/HER2- ABC	15 December 2017 to 31 August 2023
Demographic of HR+/HER2- ABC patients who were treated with palbociclib plus ET in routine clinical practice in Japan	15 December 2017 to 31 August 2023
Clinical characteristics of HR+/HER2- ABC patients who were treated with palbociclib plus ET in routine clinical practice in Japan	15 December 2017 to 31 August 2023
Treatment patterns of palbociclib plus ET in routine clinical practice in Japan	15 December 2017 to 31 August 2023

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): April 20, 2022
• Primary Completion (Actual): June 27, 2025
• Study Completion (Actual): June 27, 2025

Study Registration Dates

• First Submitted: May 26, 2022
• First Submitted That Met QC Criteria: May 26, 2022
• First Posted (Actual): June 1, 2022

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Advanced Breast Cancer; Observational; Effectiveness; Japan; Multicenter; Retrospective; Palbociclib; First-line therapy; Endocrine therapy; Real-world progression free survival; Hormone receptor positive/ human epidermal growth factor negative (HR+/HER2-); Second-Line therapy
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms; Antineoplastic Agents; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Protein Kinase Inhibitors; palbociclib
• Other Study ID Numbers: A5481166; NCT05399329 (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.