Study to Evaluate Overall Survival in Japanese Patients With HR+/HER2- Advanced Breast Cancer Treated With Palbociclib Plus Letrozole

NCT04735367 | Completed Results

• 2 other identifiers: A5481154NCT04735367
• Study Type: observational
• Target: 42
• Locations: 1 country
• Sites: 13

Brief Summary

This is a retrospective, multicenter, observational study in Japan. The primary objective is to evaluate overall survival (OS) in Japanese patients with HR+/HER2- advanced breast cancer who have been treated with palbociclib plus letrozole. This observational study was planned as follow-up study of Japanese phase 2 study of palbociclib (NCT01684215, phase 2 portion of A5481010 study).

Conditions

Breast Cancer

Keywords

retrospective; multicenter; observational study; Japan; HR+/HER2- advanced breast cancer; palbociclib; overall survival

Outcome Measures

Primary Outcomes (1)

• Overall Survival (OS)

  OS was defined as the time from the date of the first dose of the investigational product in Japanese Phase 2 study (A5481010) to the date of any-cause death. In the absence of confirmation of death, survival time was censored to last date the participant was known to be alive. Kaplan-Meier method was used for analysis.

  From the date of the first dose of the treatment in study A5481010 to the date of any-cause death or censoring date (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 study

Secondary Outcomes (2)

• Percentage of Participants According to Types and Line of Subsequent Treatment

  From start of subsequent treatment in study A5481010 until date of death, withdrawal of consent or end of study (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 study

• Duration of Subsequent Therapy by Line of Therapy

  From start of subsequent treatment in study A5481010 until date of death, withdrawal of consent or end of study (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 study

Interventions

palbociclib plus letrozole DRUG

palbociclib plus letrozole

Eligibility Criteria

• Age: 20 Years+
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients who participated, treated with palbociclib plus letrozole, and under follow-up for survival in J-Ph2

You may qualify if:

• Participated, treated with palbociclib plus letrozole in J-Ph2, and was under follow-up for survival at the study completion of J-Ph2.
• For patients who are still alive and have routine visits to the study site, evidence of a personally signed and dated informed consent document indicating that the patient has been informed of all pertinent aspects of the study. For patients who are still alive and had been transferred to another hospital, evidence that the patient has been informed of all pertinent aspects of the study and oral or written informed consent is obtained. For patients who had already passed away, the conduct of this study will be disclosed, and the patients' legally acceptable representatives will be guaranteed an opportunity to refuse data collection for the patients in accordance with the Ethical Guidelines for Medical and Health Research Involving Human Subjects

Sponsors & Collaborators

• Pfizer: lead

Study Sites (13)

Chiba cancer center

Chiba, Chiba, 260-8717, Japan

Location

National Hospital Organization Shikoku Cancer Center

Matsuyama, Ehime, 791-0280, Japan

Location

Hiroshima City Hiroshima Citizens Hospital

Hiroshima, Hiroshima, 730-8518, Japan

Location

National Hospital Organization Hokkaido Cancer Center

Sapporo, Hokkaido, 003-0804, Japan

Location

Kumamoto University Hospital

Kumamoto, Kumamoto, 860-8556, Japan

Location

Saitama Cancer Center

Kita-adachi-gun, Saitama, 362-0806, Japan

Location

National Cancer Center Hospital

Chuo-ku, Tokyo, 104-0045, Japan

Location

National Hospital Organization Kyushu Cancer Center

Fukuoka, 811-1395, Japan

Location

Hakuaikai Medical Corporation Sagara Hospital

Kagoshima, 892-0833, Japan

Location

Kumamoto Shinto General Hospital

Kumamoto, 862-8655, Japan

Location

Kyoto University Hospital

Kyoto, 606-8507, Japan

Location

Aichi Cancer Center

Nagoya, 464-8681, Japan

Location

National Hospital Organization - Osaka National Hospital - Institute For Clinical Research

Osaka, 540-0006, Japan

Location

Related Publications (2)

• Takahashi M, Yasojima H, Osako T, Inoue K, Kawashima M, Maeda H, Ito M, Sagara Y, Yonemori K, Hattori M, Yamamoto N, Muramatsu Y, Matsui A, Masuda N. Overall survival and subsequent therapy patterns in Japanese patients with ER+/HER2- advanced breast cancer treated with palbociclib plus letrozole in the first-line setting: a final analysis. Breast Cancer. 2025 Nov;32(6):1482-1490. doi: 10.1007/s12282-025-01760-0. Epub 2025 Aug 21.

  PMID: 40841781 DERIVED

• Takahashi M, Osako T, Yasojima H, Inoue K, Kawashima M, Maeda H, Ichikawa A, Muramatsu Y, Masuda N. Overall survival in Japanese patients with ER+/HER2- advanced breast cancer treated with first-line palbociclib plus letrozole. Breast Cancer. 2024 Jan;31(1):53-62. doi: 10.1007/s12282-023-01511-z. Epub 2023 Oct 26.

  PMID: 37882974 DERIVED

Related Links

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

MeSH Terms

Conditions

Breast Neoplasms

Interventions

palbociclib; Letrozole

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Intervention Hierarchy (Ancestors)

Nitriles; Organic Chemicals; Triazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Results Point of Contact

• Title: Pfizer ClinicalTrials.gov Call Center
• Organization: Pfizer Inc.

ClinicalTrials.gov_Inquiries@pfizer.com

1-800-718-1021

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 28, 2021
• First Posted: February 3, 2021
• Study Start: February 3, 2021
• Primary Completion: September 29, 2023
• Study Completion: September 29, 2023
• Last Updated: December 9, 2025
• Results First Posted: December 9, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

JP (13)