TREATMENT AND MONITORING PATTERNS AND CLINICAL OUTCOMES IN PATIENTS RECEIVING PALBOCICLIB COMBINATION TREATMENT (WITH AI OR FULVESTRANT) FOR HR+/HER2- A/MBC IN A COMMUNITY ONCOLOGY SETTING.

February 25, 2026 updated by: Pfizer

TREATMENT AND MONITORING PATTERNS AND CLINICAL OUTCOMES IN PATIENTS RECEIVING PALBOCICLIB PLUS AROMATASE INHIBITOR OR PALBOCICLIB PLUS FULVESTRANT AS TREATMENT OF HORMONE RECEPTOR POSITIVE (HR+)/HUMAN EPIDERMAL GROWTH FACTOR RECEPTOR 2 NEGATIVE (HER2-) ADVANCED OR METASTATIC BREAST CANCER IN A REAL WORLD COMMUNITY ONCOLOGY SETTING

This is a retrospective, observational study that will document the treatment and monitoring patterns and clinical outcomes of patients diagnosed with HR+/HER2- a/mBC who received Palbociclib combination therapy with aromatase inhibitors or fulvestrant in the a/mBC community oncology setting.

Study Overview

Status

Completed

Conditions

Study Type

Observational

Enrollment (Actual)

1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • New York
      • New York, New York, United States, 10017
        • Pfizer United States

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study will include adult patients aged 18 years and older, diagnosed with HR+/HER2- a/mBC who received Palbociclib combination therapy with AI or fulvestrant on or after 2/3/2015.

Description

Inclusion Criteria:

Patients who are represented in the Vector Oncology Data Warehouse who meet all of the following criteria will be eligible for inclusion in the study.

  • Female.
  • Diagnosis of female breast cancer with evidence of metastatic disease or advanced disease.
  • Diagnosis (confirmed by clinical review) of advanced or metastatic breast cancer at any time, defined as breast cancer at stage IIIb, stage IIIc, or stage IV or identified as having distant metastasis.
  • Indication in the record of ER or PR positive disease, or absence of any indication of ER and PR negative disease (ie, patients are eligible without affirmative indication of ER/PR+ status as long as ER/PR- indication is not present).
  • Receipt of a palbociclib plus aromatase inhibitor (AI) or palbociclib plus fulvestrant regimen on 2/3/2015 or later in the advanced and metastatic setting. Data collection will prioritize accrual of patients with 1L use of palbociclib plus AI and with 2L use of palbociclib plus fulvestrant before collecting other use of palbociclib users.
  • Age greater than or equal to 18 years at A/MBC diagnosis.

Exclusion Criteria:

-There are no exclusion criteria for this study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Breast cancer patients
HR+/HER2- advanced/metastatic breast cancer patients in the USA.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Proportion of patients receiving various cancer treatment regimens
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Proportion of patients receiving each therapy sequence across lines
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Treatment persistence
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Progression Free Survival (PFS)
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Overall Survival (OS)
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Tumor response rate
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Proportion of patients that experience dose adjustment
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)
Proportion of patients who discontinue therapy
Time Frame: A/MBC diagnosis through end of study (assessed up to 24 months)
A/MBC diagnosis through end of study (assessed up to 24 months)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Pfizer

Investigators

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2018

Primary Completion (Actual)

July 1, 2018

Study Completion (Actual)

July 1, 2018

Study Registration Dates

First Submitted

August 3, 2020

First Submitted That Met QC Criteria

August 3, 2020

First Posted (Actual)

August 4, 2020

Study Record Updates

Last Update Posted (Actual)

February 27, 2026

Last Update Submitted That Met QC Criteria

February 25, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • A5481095

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.

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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