A Real-world Analysis of Concomitant Medication Use Among Metastatic Breast Cancer Patients Treated With CDK4/6 Inhibitors

Study Overview
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Brief Summary
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This is a retrospective cohort study to assess the real-world analysis of concomitant medication use among metastatic breast cancer patients treated with CDK4/6 inhibitors utilizing the US Optum research administrative claims database.

Detailed Description
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This is a retrospective cohort study utilizing the US Optum research administrative claims database. Adult female patients who had HR+/HER2- mBC were identified and included in the study. These patients were stratified into three cohorts based on the first CDK4/6i received (ribociclib, palbociclib, or abemaciclib). Study period: Period during which all relevant medical and pharmacy information in the database was retrieved Index event identification period: time frame during which index treatment was identified First CDK4/6i: the date on which patients initiated their first treatment after being diagnosed with HR+/HER2- mBC; this date was considered as the index date Baseline period: Time frame during which patient characteristics, prior mBC treatments, and concomitant treatments received by CDK4/6i-naïve patients were evaluated Follow-up period: time frame on and after the index date during which patients' treatments and dosing patterns were observed Establishment of baseline period Health plan enrollment in the three months prior to the index treatment was included in the baseline period. Patient demographics, clinical characteristics, National Cancer Institute (NCI) comorbidity index, concomitant medication use that can potentially lead to a DDI, and other BC treatments prior to the index treatment were evaluated during this period. Establishment of follow-up period Patients were observed for ≥3 months starting from the index date until the end of the study period or continuous enrollment or until the time when patients switched to another therapy (including another CDK4/6i), whichever came first. Dosing patterns for CDK4/6i were evaluated in the follow-up period. Analyses were conducted at key time points of 3, 6, and 12 months

Official Title
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A Real-world Analysis of Concomitant Medication Use Among Metastatic Breast Cancer Patients Treated With CDK4/6 Inhibitors

Conditions
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Metastatic Breast Cancer

Intervention / Treatment
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* Drug: Ribiciclib
* Drug: Palbociclib
* Drug: Abemaciclib


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Treated with CDK4/6i from 2015-02-01 to 2019-06-30 ≥2 claims with a BC diagnosis recorded ≥30 days apart from the index date ≥2 claims with an mBC diagnosis, with a time interval between the first BC diagnosis date and the first mBC diagnosis date no longer than 30 days Female patients aged ≥18 years Continuous health plan enrollment for ≥3 months prior to the index date and ≥3 months post-index date Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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Female

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 |
| --- | --- |
| Ribociclib<br>Participants who initiated CDK4/6i therapy | Drug: Ribiciclib<br>* Participants who initiated CDK4/6i therapy<br>|
| Palbociclib<br>Participants who initiated CDK4/6i therapy | Drug: Palbociclib<br>* Participants who initiated CDK4/6i therapy<br>|
| Abemaciclib<br>Participants who initiated CDK4/6i therapy | Drug: Abemaciclib<br>* Participants who initiated CDK4/6i therapy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with a prescription fill of ribociclib, palbociclib, or abemaciclib | Distribution of patients with a prescription fill of ribociclib, palbociclib, or abemaciclib at index treatment date will be present by frequency among all patients treated with CDK4/6 | Index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) | 
| Number of participants who took concomitant medications in baseline period, by drug name | Number of patients taking a concomitant medication/s during baseline period that can potentially lead to a drug-drug interactions (DDI) with a CDK4/6 inhibitor use with each CDK4/6 inhibitor in the follow-up period. | Baseline period (3 months) | 
| Number of participants who took concomitant medications in follow-up period, by drug name | Number of patients taking a concomitant medication/s during baseline period that can potentially lead to a drug-drug interactions (DDI) with a CDK4/6 inhibitor use with each CDK4/6 inhibitor in the follow-up period. | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 
| Number of participants with no use of concomitant medications | Adherence to concomitant medications during the baseline period was reported | Baseline period (3 months) | 
| Number of participants with proportion of days covered (PDC) >80% | Adherence to concomitant medication during the baseline period will be assessed using the proportion of days covered (PDC): PDC = total days of filled or refilled concomitant Rx in baseline period / total number of days in baseline period | Baseline period (3 months) | 
| Number of participants with proportion of days covered (PDC) ≤80% | Adherence to concomitant medication during the baseline period will be assessed using the proportion of days covered (PDC): PDC = total days of filled or refilled concomitant Rx in baseline period / total number of days in baseline period | Baseline period (3 months) | 
| Number of other breast cancer medications used | Number of other breast cancer medications used in baseline period, by drug class (HR+/Endocrine, Chemotherapy, Other treatments), for breast cancer regimens was reported | Baseline period (3 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean starting dose for each CDK4/6 | Distribution of starting dose and mean starting dose for each CDK4/6 was reported to describe dosing and treatment patterns associated with ribociclib, palbociclib, and abemaciclib patients | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 
| Number of participants who had any dose change (increase, decrease) | Number of patients with change in dose by each CDK4/6 inhibitor (ribociclib, palbociclib, and abemaciclib) in the follow-up period was reported | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 
| Number of participants who had a dose increase | Number of patients with change in dose by each CDK4/6 inhibitor (ribociclib, palbociclib, and abemaciclib) in the follow-up period was reported | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 
| Number of participants who had a dose decrease | Number of patients with change in dose by each CDK4/6 inhibitor (ribociclib, palbociclib, and abemaciclib) in the follow-up period was reported | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 
| Number of participants discontinuing each CDK4/6i (ribociclib, palbociclib, or abemaciclib) | Rate of discontinuation of ribociclib, palbociclib, or abemaciclib in the follow-up period was reported | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 
| Median duration of treatment (in months) by each CDK4/6i (ribociclib, palbociclib, or abemaciclib) | Duration of treatment with ribociclib, palbociclib, or abemaciclib, defined as discontinuation of each index CDK 4/6 treatment during the follow-up period was reported | From index date (defined as the prescription fill for ribociclib, palbociclib, or abemaciclib for the first time) to the end of follow-up period (12 months post index date) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Concomitant medication,, drug-drug interaction,, CDK4/6 inihibitor,, HR+/HER2-metastatic breast cancer