A Study to Learn About the Dangers Linked to 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 explore risk factors for grade 4 neutropenia in users of the study medicine Palbociclib for the potential treatment of Palbociclib. This study is seeking participants: treated with the study medicine Palbociclib having any breast cancer records in same month as the initiation date having prescription records of palbociclib from 15 December 2017 to 29 February 2024 The study design is a nested case control study. This study design uses de-identified patient data from a hospital based electronic medical record and claim database in Japan. This design was selected since the primary objective is to explore risk factors of Grade 4 neutropenia in users of the study medicine Palbociclib. 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 effect of Palbociclib in decreasing the neutrophil count 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. Patients who develop grade 4 neutropenia after palbociclib initiation will be matched to controls who do not develop grade 4 neutropenia. A statistical model will be used to explore risk factors of grade 4 neutropenia adjusted for important potential confounding factors.

Official Title
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Evaluation of Risk Factors Associated With Myelosuppression (Grade 4 Neutropenia) in Breast Cancer Patients Treated With Palbociclib in the Post-marketing Setting: Nested Case-control 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. Exclusion Criteria: Having an 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 |
| --- | --- |
| Case: G4 neutropenia occurs after palbociclib initiation<br>Grade 4 neutropenia occurs after initiation of palbociclib Note that: Case patients are categorized as control before incurring grade 4 neutropenia | |
| Control: G4 neutropenia does not occur after palbociclib initiation<br>Grade 4 neutropenia does not occur after initiation of palbociclib | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Risk Factors for Grade 4 Neutropenia in Users of Palbociclib | Grade 4 neutropenia, as the outcome of this study, will be defined as an absolute neutrophil count (ANC) of less than 0.5 × 109 cells/L or less than 500 cells/mL during the on-treatment period. | 01 Jun 2017 through 29 Feb 2024 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Risk Factors 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 × 109 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, data base study in Japan, Ibrance, Palbociclib, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-), inoperable or recurrent breast cancer