A Study to Understand About the Study Medicine Palbociclib in Breast Cancer Patients After it is Out in the Japanese Market

Completed

• Conditions: Breast Neoplasms
• Interventions: Drug: palbociclib plus fulvestrant; Drug: fulvestrant

• Registration Number: NCT07096024
• Lead Sponsor: Pfizer

Brief Summary

The purpose of the study is to:

* compare the chances of getting interstitial lung disease (ILD) in new users of palbociclib plus fulvestrant to new users of fulvestrant alone (using data from before palbociclib was out in the market)

* look into the factors that can cause ILD in new users of palbociclib.

This study uses patient data without giving out any personal information of the patient. This data is taken from a hospital-based claims database of the MDV database, that includes data from more than 400 hospitals in Japan.

This study will use data of patients who are:

* diagnosed with breast cancer that include newly treated with palbociclib and/or other endocrine-based therapies for inoperable or recurrent breast cancer between 25 November 2011 and 30 November 2024.

Detailed Description

Not available

Study Timeline

• Study Start: 2025-01-21
• Primary Completion: 2025-02-07
• Study Completion: 2025-02-07
• Status Verified: 2025-07
• Study First Submitted: 2025-07-24
• Study First Submitted QC: 2025-07-24
• Last Update Submitted: 2025-07-24
• Study First Posted: 2025-07-31
• Last Update Posted: 2025-07-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 2000

Inclusion Criteria

• Having prescription records of drugs for endocrine therapy (aromatase inhibitors, SERDs, SERMs, and CDK4/6 inhibitors) from 25 November 2011 to 31 December 2024.
• Having any breast cancer records with definitive diagnosis in the same month as the first prescription date.
• Having any records in MDV database on or before 6 months prior to the first prescription date (<= -180 days: first prescription date = 0 day).
• Having any records in MDV database within 6 months prior to the first prescription date (-180 days to 0 day).

Exclusion Criteria

• Having any records of anti-HER2 medication (e.g., trastuzumab, pertuzumab, lapatinib or trastuzumab emtansine) from 25 November 2011 to 31 December 2024.
• Having any records of second primary cancer with definitive diagnosis

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
New prescription of palbociclib with fulvestrant.	palbociclib plus fulvestrant	Patients treated with the combination of palbociclib and fulvestrant
New prescription of palbociclib with fulvestrant.	fulvestrant	Patients treated with the combination of palbociclib and fulvestrant
New prescription of fulvestrant monotherapy before the launch of palbociclib	fulvestrant	Patients treated with fulvestrant alone

Primary Outcome Measures

Name	Time	Method
The hazard ratios of ILD in palbociclib plus fulvestrant to new users of fulvestrant alone	25 November 2011 and 30 September 2024
The rate ratios of ILD in palbociclib plus fulvestrant to new users of fulvestrant alone	25 November 2011 and 30 September 2024
The rate differences of ILD in palbociclib plus fulvestrant to new users of fulvestrant alone	25 November 2011 and 30 September 2024
The incidence rate of ILD by each risk factor in new users of palbociclib	25 November 2011 and 30 September 2024

Secondary Outcome Measures

Name	Time	Method
The incidence rate of ILD by each risk factor in new users of endocrine-based therapies including combination with CDK4/6 inhibitors	25 November 2011 and 30 September 2024

Trial Locations

Locations (1)

Pfizer New York; 🇺🇸 New York, New York, United States