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

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).

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Key information

Conditions

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

Age range

20 year and older

Sex eligibility

Female

Study type

Observational

Primary location

Chiba cancer center, Chiba, Japan

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

There are no exclusion criteria for this study.

Treatment and study plan

palbociclib plus letrozole

Drug

palbociclib plus letrozole

Primary outcomes

Overall Survival (OS)

Time frame: 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

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.

Secondary outcomes

Percentage of Participants According to Types and Line of Subsequent Treatment

Time frame: 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

Participants were classified based on types of subsequent treatment and by line of subsequent treatment. Subsequent treatments included: endocrine therapy-based, chemotherapy-based and others (Investigational drug + Endocrine therapy/Chemotherapy).
Duration of Subsequent Therapy by Line of Therapy

Time frame: 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 defined as time from the start date to the end date of each line of treatment among participants who received subsequent treatment. Kaplan-Meier method was used.

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Registry information

Official study title

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

Important dates

Study start: 2021
Primary completion: 2023
Study completion: 2023
First posted: Feb 3, 2021
Registry last updated: Dec 9, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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