A Real-life Study to Understand the Use and Effects of Palbociclib in US Patients With Breast Cancer

NCT06495164 | Active Not Recruiting FDA Drug

• 2 other identifiers: A5481189NCT06495164
• Study Type: observational
• Target: 1
• Locations: 1 country
• Sites: 1

Brief Summary

Palbociclib, the first oral CDK4/6 inhibitor, is an approved medicine indicated for the treatment of a kind of advanced/metastatic breast cancer (MBC), called hormone receptors positive (HR+)/ Human epidermal growth factor receptor 2 negative (HER2-) disease. Palbociclib is given orally in combination with hormonal therapies. The purpose of this study is to better understand how Palbociclib combination is used in real-life conditions and its clinical impact compared with hormonal therapy. The study will also evaluate how long patients take the different CDK 4/6 inhibitor drugs and whether using those drugs impacts the use of chemotherapy later. Male and female patients aged 18 years old or more presenting the following conditions will be selected for the study:

• HR+/HER2- MBC
• First treatment with Palbociclib, hormonal therapy, or other CDK4/6 inhibitors after MBC diagnosis The study will use data without personal identity, which were obtained from medical records in routine clinical practice.

Conditions

Breast Cancer; Malignant Neoplasm of Breast

Keywords

Metastatic breast cancer; CDK4/6 inhibitor; Real-world data; Retrospective observational study; Palbociclib; Overall survival

Outcome Measures

Primary Outcomes (1)

• Overall Survival (OS)

  From start of index line of therapy to death, February 2015 - December 2022 or data cutoff

Secondary Outcomes (5)

• Real Progression Free Survival (rwPFS)

  From start of index line of therapy to death or disease progression, February 2015 - December 2022 or data cutoff

• Progression Free Survival 2

  from start of index treatment to disease progression on the 2nd line of therapy or death, February 2015 - December 2022 or data cutoff

• Real-World Tumor Response (rwTR)

  From start of index treatment to tumor response, February 2015 - December 2022 or data cutoff

• Duration of treatment

  from index treatment initiation to end of the treatment, February 2015 - December 2022 or data cutoff

• Time to chemotherapy

  from index treatment initiation to subsequent chemotherapy, February 2015 - December 2022 or data cutoff

Other Outcomes (2)

• Early discontinuation

  from index treatment initiation to discontinuation between February 2015 - December 2022 or data cutoff

• Dose adjustment

  from index treatment initiation to initial dose change, February 2015 - December 2022 or data cutoff

Study Arms (4)

Palbociclib + aromatase inhibitor (AI)

Oral palbociclib + AI combination treatment regimen as decided by physician

Drug: Palbociclib; Drug: Aromatase inhibitor

Aromatase inhibitor (AI)

Oral AI treatment regimen as decided by physician

Drug: Aromatase inhibitor

Abemaciclib plus aromatase inhibitor (AI)

Oral abemaciclib plus AI treatment regimen as decided by physician

Drug: Palbociclib; Drug: Aromatase inhibitor; Drug: Abemaciclib

Ribociclib plus aromatase inhibitor (AI)

Oral ribociclib plus AI as decided by physician

Drug: Aromatase inhibitor; Drug: Ribociclib

Interventions

Palbociclib DRUG

CDK4/6 inhibitor

Also known as: Ibrance

Abemaciclib plus aromatase inhibitor (AI); Palbociclib + aromatase inhibitor (AI)

Aromatase inhibitor DRUG

Aromatase inhibitor

Also known as: a class of drugs included in the study: letrozole (Femara), anastrozole (Arimidex), and exemestane (Aromasin)

Abemaciclib plus aromatase inhibitor (AI); Aromatase inhibitor (AI); Palbociclib + aromatase inhibitor (AI); Ribociclib plus aromatase inhibitor (AI)

Ribociclib DRUG

CDK4/6 inhibitor

Also known as: Kisqali

Ribociclib plus aromatase inhibitor (AI)

Abemaciclib DRUG

CDK4/6 inhibitor

Also known as: Verzenio

Abemaciclib plus aromatase inhibitor (AI)

Eligibility Criteria

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

Study Population

Flatiron Health Database is a longitudinal, demographically, and geographically diverse dataset derived from EHR data from over 280 cancer clinics (\~800 sites of care) including more than 3.0 million active US cancer patients available for analysis. This study uses secondary de-identified Flatiron Health data that involve men and women who had been diagnosed with HR+/HER2-MBC in the United States.

Patients are eligible for the study if they were 18 years of age or older at MBC diagnosis, had HR+/HER2- confirmed and initiated first line therapy (CDK4/6i, ET, CT, or other) in the metastatic setting during the period from February 2015 through June 2022 or data cutoff.

Contact the study team to discuss eligibility requirements. They can help determine if this study is right for you.

Sponsors & Collaborators

• Pfizer: lead

Study Sites (1)

Pfizer New York

New York, New York, 10001, United States

Location

Related Publications (1)

• Lynce F, Liu X, Li B, McRoy L, Chen C, Liu R, Rugo HS. Real-world effectiveness of palbociclib plus an aromatase inhibitor in HR+/HER2- MBC patients living in disadvantaged neighborhoods. NPJ Breast Cancer. 2025 Jul 21;11(1):75. doi: 10.1038/s41523-025-00786-z.

  PMID: 40691446 DERIVED

Related Links

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

MeSH Terms

Conditions

Breast Neoplasms

Interventions

palbociclib; Aromatase Inhibitors; Letrozole; Anastrozole; exemestane; ribociclib; abemaciclib

Condition Hierarchy (Ancestors)

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

Intervention Hierarchy (Ancestors)

Steroid Synthesis Inhibitors; Enzyme Inhibitors; Molecular Mechanisms of Pharmacological Action; Pharmacologic Actions; Chemical Actions and Uses; Estrogen Antagonists; Hormone Antagonists; Hormones, Hormone Substitutes, and Hormone Antagonists; Physiological Effects of Drugs; Nitriles; Organic Chemicals; Triazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Study Design

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

Study Record Dates

• First Submitted: July 3, 2024
• First Posted: July 10, 2024
• Study Start: June 24, 2024
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): December 30, 2026
• Last Updated: November 25, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)