A Study of HR+/HER2- Metastatic Breast Cancer Patients Treated With Palbociclib Together With an Aromatase Inhibitor From 2017 to 2023 in Denmark.

Impact of Age and Comorbidities on Treatment Outcomes of First-line Treatment With Palbociclib in Combination With an Aromatase Inhibitor (AI) in Patients Diagnosed With HR+/HER2 - Metastatic Breast Cancer - Danish Non-Interventional Study

The purpose of this study is to describe the effect of the medicine palbociclib when given together with an aromatase inhibitor for treatment of breast cancer. The study will consider participants who:

• have advanced or metastatic breast cancer that is spread to other parts of the body.

• have HR+/HER2- (hormone receptor positive* / human epidermal growth factor receptor 2 negative**) breast cancer types.

  • Hormone receptor positive (HR+): are cells that have a group of proteins that bind to a specific hormone. For example, some breast cancer cells have receptors for the hormones estrogen or progesterone.

These cells are hormone receptor positive, and they need estrogen or progesterone to grow. This can affect how the cancer is treated. Knowing if the cancer is hormone receptor positive may help plan treatment.

• Human epidermal growth factor receptor 2 negative (HER2-): cells that have a small amount or none of a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. Cancer cells that are HER2 negative may grow more slowly and are less likely to recur (come back) or spread to other parts of the body than cancer cells that have a large amount of HER2 on their surface. Checking to see if a cancer is HER2 negative may help plan treatment.

  • have started treatment in the period between January 2017 and December 2021.

The study will describe the treatment effect for different patient groups in terms of age and comorbidities. Comorbidity is the condition of having two or more diseases at the same time. The data is collected by the Danish Breast Cancer Group in the period between 2017 to 2023.

Study Overview

• Status: Completed
• Conditions: Breast Cancer
• Intervention / Treatment: Drug: Palbociclib in combination with AI

• Study Type: Observational
• Enrollment (Actual): 604

Contacts and Locations

Study Locations

• Denmark
  • Copenhagen, Denmark, 2100
    • Copenhagen University Hospital, Rigshospitalet

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The full dataset consists of endocrine sensitive, endocrine resistant and de novo HR+/HER2- mBC patients treated with palbociclib as first-line treatment (01 January 2017- 31 December 2021). Patients will be censored for OS and PFS by 31 December 2023.

Description

Inclusion Criteria:

• Patients with breast cancer (ICD-10: C50)
• A diagnosis of HR+/HER2- locally advanced or metastatic breast cancer
• Endocrine sensitive, endocrine resistant, or de novo mBC patient
• Inclusion date: Date of relapse/stage IV disease/progression leading to initiation of palbociclib+AI

Exclusion Criteria:

• There are no exclusion criteria for this study

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Palbociclib in combination with AI; Patients with HR+/HER2- locally advanced or metastatic breast cancer treated with palbociclib in combination with AI, in Denmark.	Drug: Palbociclib in combination with AI; Patients with HR+/HER2- locally advanced or metastatic breast cancer treated with palbociclib in combination with AI as first-line treatment, in Denmark.; Other Names: Ibrance

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-Free Survival (PFS)	PFS was defined as the time from the index date to progression or death, whichever occurred first. Progression of disease was based on scans and blood testing results. Disease progression was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 millimeters (mm). Index date was date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body. Kaplan-Meier method was used for analysis.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
Overall Survival (OS)	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. Participants were censored for OS by 1 February 2024. Index date was the date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PFS Based on Age of Participants	PFS was defined as the time from the index date to progression or death, whichever occurred first. Progression of disease was based on scans and blood testing results. Disease progression was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Kaplan-Meier method was used for analysis. PFS per age category (< 65 years, 65-75 years and > 75 years) were reported in this outcome measure. Index date was the date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Based on Age of Participants	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. Participants were censored for OS by 1 February 2024. OS per age category such as < 65 years, 65-75 years and >75 years were reported in this outcome measure. Index date was the date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
PFS Per Charlson Comorbidity Index (CCI) Score	PFS was defined as the time from the index date to progression or death, whichever occurred first. CCI was used as data source for comorbidity. Each comorbidity recorded for participant, had score between 0 to 6 as per comorbidity burden, if it was part of CCI. Higher score=more severe comorbidity status. CCI score 0:participants with no comorbidity besides BC disease, CCI score 1:participant with one comorbidity with score of 1,e.g.,myocardial infarction or diabetes mellitus(DM), CCI score 2:participant with two comorbidities each classified with score of 1 or one single comorbidity classified with score of 2,e.g.,DM with organ damage, CCI score of 3or higher: participant with severe comorbidity, i.e. those having one comorbidity classified with score of 6(e.g., Human Immunodeficiency Virus/Acquired Immuno Deficiency Syndrome),or two or more comorbidities each classified with scores of1-2,all in addition to participant's BC disease. Index date=date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Per CCI Score	OS: time from date of relapse or stage IV disease to death at any cause. CCI was used as data source for comorbidity in study. For each comorbidity recorded for participant score between 0 to 6 was assigned based on comorbidity burden, whether it was part of CCI.Higher score=more severe comorbidity status.CCI scores: CCI score 0:participants with no comorbidity besides BC disease, CCI score 1:participant with one comorbidity with score of 1,e.g., myocardial infarction or DM,CCI score 2:participant with two comorbidities each classified with score of 1 or one single comorbidity classified with score of 2,e.g.,DM with organ damage, CCI score of 3 or higher: participant with severe comorbidity,i.e.those having one comorbidity classified with score of 6(e.g., Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome),or two or more comorbidities each classified with scores of 1-2,all in addition to participant's BC disease. Index date=date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
PFS Per Number of Comorbidities	PFS was defined as the time from the index date to progression or death, whichever occurred first. Participants were censored for PFS by 1 February 2024. Progression was based on radiological, clinical, and biochemical examination from the treating departments. Participants were split into three comorbidity groups - no comorbidity (0), one comorbidity and two or more comorbidities. Comorbidities included myocardial infarction, congestive heart failure (CHF), peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, ulcer disease, mild liver disease, DM, hemiplegia, moderate-severe renal disease, DM with end organ damage, any tumor, leukemia, lymphoma, moderate-severe liver disease, metastatic solid tumor and acquired immune deficiency syndrome/human immune virus (AIDS/HIV). Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Per Number of Comorbidities	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. Participants were split into three comorbidity groups - no comorbidity (0), one comorbidity and two or more comorbidities. Comorbidities included myocardial infarction, CHF, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, ulcer disease, mild liver disease, DM, hemiplegia, moderate-severe renal disease, DM with end organ damage, any tumor, leukemia, lymphoma, moderate-severe liver disease, metastatic solid tumor and AIDS/HIV. Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
PFS Per Type of Comorbidity	PFS was defined as the time from the index date to progression or death, whichever occurred first. Participants were censored for PFS by 1 February 2024. Progression was based on radiological, clinical, and biochemical examination from the treating departments. Comorbidities were categorized into five main disease groups: cardiac disease, vascular disease, metabolic disease, psychiatric disease and blood and lymphatic system. Results for cardiac disease, vascular disease and metabolic disease have been reported in this outcome measure. Index date was the date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Per Type of Comorbidity	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. Comorbidities were categorized into five main disease groups: Cardiac disease, vascular disease, metabolic disease, psychiatric disease and blood and lymphatic system. Results for cardiac disease, vascular disease and metabolic disease have been reported in this outcome measure. Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
PFS Per Visceral Disease Status	PFS was defined as the time from the index date to progression or death, whichever occurred first. Participants were censored for PFS by 1 February 2024. Progression was based on radiological, clinical, and biochemical examination from the treating departments. Visceral disease status was defined as metastases in the visceral organs, e.g., lung, liver. Non-visceral disease status was defined as metastases in the non-visceral organs, e.g., bone, skin, lymph nodes. PFS in participants with visceral and non-visceral disease status is reported in this outcome measure. Index date was the date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Per Visceral Disease Status	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. Visceral disease status was defined as metastases in the organs, e.g., lung, liver. Non-visceral disease status was defined as metastases in the non-visceral organs, e.g., bone, skin, lymph nodes. OS per visceral disease status was reported as visceral and non-visceral disease status in this outcome measure. Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
PFS Per Bone Disease Status	PFS was defined as the time from the index date to progression or death, whichever occurred first. Participants were censored for PFS by 1 February 2024. Progression was based on radiological, clinical, and biochemical examination from the treating departments. PFS was reported in participants with bone only (metastasis within bones) and non-bone only (metastasis within organs excluding bones) disease status in this outcome measure. Index date was the date of relapse or stage IV disease. Stage IV disease means that the cancer has spread to distant parts of the body.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Per Bone Disease Status	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. OS was reported in participants with bone only (metastasis within bones) and non-bone only (metastasis within organs excluding bones) disease status in this outcome measure. Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
PFS Per Endocrine Status	PFS was defined as the time from the index date to progression or death, whichever occurred first. Participants were censored for PFS by 1 February 2024. Progression was based on radiological, clinical, and biochemical examination from the treating departments. Endocrine resistant participants were defined as recurrent participants with advanced disease within 12 months of completing adjuvant endocrine therapy or during adjuvant endocrine therapy. Endocrine sensitive participants were defined as recurrent participants with advanced disease after 12 months of completing adjuvant endocrine therapy, recurrent participants who received no adjuvant endocrine therapy or participants with de novo, advanced breast cancer. De novo participants were defined as newly metastatic participants. Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)
OS Per Endocrine Status	OS was defined as the time from date of relapse or stage IV disease (index date) to death at any cause. OS per endocrine status was reported in participants with endocrine resistant, endocrine sensitive and de novo metastatic status in this outcome measure. Endocrine resistant participants were defined as recurrent participants with advanced disease within 12 months of completing adjuvant endocrine therapy or during adjuvant endocrine therapy. Endocrine sensitive participants were defined as recurrent participants with advanced disease after 12 months of completing adjuvant endocrine therapy, recurrent participants who received no adjuvant endocrine therapy or participants with de novo, advanced breast cancer. De novo participants were defined as newly metastatic participants. Index date was the date of relapse or stage IV disease.	From index date to disease progression or death or censoring date, whichever occurred first (data collected from 1 January 2017 to 1 February 2024 [maximum up to 7.09 years] and observed retrospectively for approximately 1.3 months of this study)

Collaborators and Investigators

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

Publications and helpful links

Helpful Links

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

Study record dates

Study Major Dates

• Study Start (Actual): March 6, 2024
• Primary Completion (Actual): April 19, 2024
• Study Completion (Actual): April 19, 2024

Study Registration Dates

• First Submitted: March 5, 2024
• First Submitted That Met QC Criteria: March 11, 2024
• First Posted (Actual): March 12, 2024

Study Record Updates

• Last Update Posted (Actual): June 29, 2025
• Last Update Submitted That Met QC Criteria: June 9, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Advanced Breast Cancer; Age; Palbociclib; Charlson Comorbidity Index (CCI); Denmark; First-line Treatment; Comorbidities; HR+/HER2-; Metastatic Breast Cancer (mBC); ICD10: C50; Hormone receptor positive / Human Epidermal growth factor Receptor 2 negative; Endocrine sensitive; Endocrine resistant; de novo mBC; Danish Breast Cancer Group (DBCG); Aromatase Inhibitor (AI); Real-World Evidence (RWE); Non-Interventional Study (NIS)
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Breast Neoplasms; Antineoplastic Agents; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Protein Kinase Inhibitors; Palbociclib
• Other Study ID Numbers: A5481188; NCT06307457 (Registry Identifier: ClinicalTrials.gov)

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.