A Study to Learn About the Relationship Between Hepatic Impairment and Myelosuppression (Decreased Bone Marrow Function) in Breast Cancer Patients Treated With the Study Medicine Palbociclib (Pal-bow-sai-klib)

Study Overview
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Brief Summary
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The purpose of this study is to evaluate incidence of grade 4 neutropenia in patients who have hepatic impairment and use the study medicine Palbociclib. This study is seeking participants: treated with the study medicine Palbociclib having any breast cancer records in same month as the index date (the first prescription date) having prescription records of palbociclib from 20 December 2016 to 29 February 2024 The study design is a cohort study. This study design uses de-identified patient data from a hospital based electronic medical record and claim database in Japan. One of the important side effects of taking Palbociclib is neutropenia (decreased count of neutrophils - a type of white blood cell). In this study, the relationship between neutropenia caused by Palbociclib and hepatic impairment was studied after it was released to the market. To do that, the study gathered details of breast cancer patients newly treated with Palbociclib from 23 hospitals and 10 medical institutes across Japan. The below patient details were collected: dose of Palbociclib other medicines prescribed for cancer age gender past information on cancer treatments laboratory findings at baseline The result was based on the neutrophil count collected from the laboratory data. Around 1300 patients newly treated with Palbociclib for breast cancer was calculated by the medical information database network (MID-NET) in 6 years from 15 December 2017.

Official Title
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Evaluation of Incidence of Myelosuppression (Grade 4 Neutropenia) in Breast Cancer Patients With Mild, Moderate or Severe Hepatic Impairment Treated With Palbociclib Compared to Patients With Reserved Hepatic Function in the Post-marketing Setting: Cohort Study Using the Medical Information Database Network (MID-NET) Database

Conditions
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Breast Cancer

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Having prescription records of palbociclib from 15 December 2017 to 29 February 2024. Having any breast cancer records in same month as the first prescription date. Having laboratory tests and visit records (SS-MIX2) on or before 180 days prior to the first prescription date Having SS-MIX2 hospital-visit records within 180 days before the first prescription date Exclusion Criteria: Having an absolute neutrophil count (ANC) less than the threshold value for grade 4 neutropenia within 30 days of the first prescription of palbociclib Having any records of anti-HER2 medication

Ages Eligible for Study
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Minimum Age: 0 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cohort<br>New users of palbociclib for inoperable or recurrent breast cancer divided into 4 groups based on severity levels of hepatic impairment | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With/Without Hepatic Impairment for Grade 4 Neutropenia in New Users of Palbociclib | Grade 4 neutropenia, as the outcome of this study, will be defined as an ANC of less than 0.5 × 10^9 cells/L or less than 500 cells/mL during the on-treatment period. | 20 Dec 2016 through 29 Feb 2024 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With/Without Hepatic Impairment for Grade 3-4 Neutropenia in New Users of Palbociclib | Grade 3-4 neutropenia, as the outcome of this study, will be defined as an ANC of less than 1.0 × 10^9 cells/L or less than 500 cells/mL during the on-treatment period. | 20 Dec 2016 through 29 Feb 2024 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Safety, database study in Japan, Ibrance, Palbociclib, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-), inoperable or recurrent breast cancer