Breast CancerNCT05399329
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
An observational study of Breast Cancer, run by Pfizer at 20 sites in Japan.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 20 years and older
- Conditions the study is for
- Breast Cancer
- What is being tested?
- Palbociclib and Endocrine therapy
- How many people
- 693 participants
- Where
- 20 sitesJapan
- Study dates
- 20 Apr 2022to 27 Jun 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
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.
Who may be able to join
- 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
Who cannot join
- 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.)
Trial locations and contacts
20 sites in 1 country.
20 sites in 1 country
Japan20 sites
Gifu University Hospital
Gifu, 501-1194
Seirei Hamamatsu General Hospital
Hamamatsu, Shizuoka, 430-8558
Hiroshima University Hospital
Hiroshima, 734-8551
Kaizuka City Hospital
Kaizuka, Osaka, 597-0015
Tokai University Hospital
Kanagawa, 259-1193
Ishikawa Prefectural Central Hospital
Kanazawa, Ishikawa-ken, 920-8530
Saitama Prefectural Cancer Center
Kita-adachi-gun, Saitama, 362-0806
Japan Community Health care Organization Kurume General Hospital
Kurume, Fukuoka, 830-0013
National Hospital Organization Shikoku Cancer Center
Matsuyama, Ehime, 791-0280
Nagoya University Hospital
Nagoya, Aichi-ken, 466-8560
Aichi Cancer Center
Nagoya, 464-8681
Osaka International Cancer Institute
Osaka, Osaka, 541-8567
National Hospital Organization Osaka National Hospital
Osaka, 540-0006
Kitasato University Hospital
Sagamihara, Kanagawa, 252-0329
Hokkaido Cancer Center
Sapporo, Hokkaido, 003-0804
Tohoku University Hospital
Sendai, Miyagi, 980-8574
Jichi Medical University Hospital
Shimotsuke, Tochigi, 329 0498
Shizuoka Prefectural Hospital Organization
Shizuoka, 420-8527
Osaka University Hospital
Suita, Osaka, 565-0871
Showa University Hospital
Tokyo, 142-8666
About this study
Official title: 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.
- Conditions
- Breast Cancer
- Being tested
- Palbociclib, Endocrine therapy
- Keywords
- Retrospective, Multicenter, Observational, Effectiveness, Real-world progression free survival, Palbociclib, Endocrine therapy, Japan, Hormone receptor positive/ human epidermal growth factor negative (HR+/HER2-), Advanced Breast Cancer, First-line therapy, Second-Line therapy
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PalbociclibDrug
Palbociclib plus ET as first-line/second-line treatment for hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) ABC
Endocrine therapyDrug
Palbociclib plus ET as first-line/second-line treatment for HR+/HER2- ABC
What is being measured
The primary outcome is the main question the study is designed to answer.
Real-World Progression-Free Survival (rwPFS) of palbociclib plus ET as first line treatment for HR+/HER2- ABC
Measured: 15 December 2017 to 31 August 2023
rePFS of palbociclib plus ET as second line treatment for HR+/HER2- ABC
Measured: 15 December 2017 to 31 August 2023
Secondary outcomes (10)
Landmark overall survival (OS) (defined from palbociclib initiation to death) of palbociclib plus ET as first line treatment for HR+/HER2- ABC
Measured: 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
Measured: 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
Measured: 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
Measured: 15 December 2017 to 31 August 2023
TTD of first subsequent treatment for HR+/HER2- ABC patients who were treated with palbociclib plus ET
Measured: 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)
Measured: 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
Measured: 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
Measured: 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
Measured: 15 December 2017 to 31 August 2023
Treatment patterns of palbociclib plus ET in routine clinical practice in Japan
Measured: 15 December 2017 to 31 August 2023
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2022
- Study start20 Apr 2022
- Primary completion27 Jun 2025
- Study completion27 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 693 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05399329
- Sponsor's protocol ID
- A5481166
- Other IDs
- NCT05399329
- Status last verified
- Apr 2026
- First submitted
- 26 May 2022
- Last updated
- 9 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No: 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.
Study at a glance
From the registry record, last updated by the sponsor on 9 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT05399329
- Acronym / sponsor ID
- A5481166
- Conditions
- Breast Cancer
- Keywords
- Retrospective, Multicenter, Observational, Effectiveness, Real-world progression free survival, Palbociclib, Endocrine therapy, Japan
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 693 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 20 Apr 2022 (actual)
- Primary completion
- 27 Jun 2025 (actual)
- Study completion
- 27 Jun 2025 (actual)
- First posted
- 1 Jun 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Observational model
- Cohort
- Time perspective
- Retrospective
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- 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.
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (3 listed)
- 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.)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PalbociclibPalbociclib plus ET as first-line/second-line treatment for hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) ABC | Drug | – |
| Endocrine therapyPalbociclib plus ET as first-line/second-line treatment for HR+/HER2- ABC | Drug | – |
Primary outcome
Real-World Progression-Free Survival (rwPFS) of palbociclib plus ET as first line treatment for HR+/HER2- ABC
Time frame: 15 December 2017 to 31 August 2023
rePFS of palbociclib plus ET as second line treatment for HR+/HER2- ABC
Time frame: 15 December 2017 to 31 August 2023
10 secondary outcomes
Landmark overall survival (OS) (defined from palbociclib initiation to death) of palbociclib plus ET as first line treatment for HR+/HER2- ABC
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 15 December 2017 to 31 August 2023
TTD of first subsequent treatment for HR+/HER2- ABC patients who were treated with palbociclib plus ET
Time frame: 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)
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 15 December 2017 to 31 August 2023
Treatment patterns of palbociclib plus ET in routine clinical practice in Japan
Time frame: 15 December 2017 to 31 August 2023
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pfizer CT.gov Call Center study director
Pfizer
20 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Breast Cancer, run by Pfizer at 20 sites in Japan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 20 sites in Japan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Real-World Progression-Free Survival (rwPFS) of palbociclib plus ET as first line treatment for HR+/HER2- ABC (time frame: 15 December 2017 to 31 August 2023). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Apr 2026.