Enzalutamide vs. Abiraterone in Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer (mCRPC)

Study Overview
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Brief Summary
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This study will be a retrospective data analysis to compare outcomes between patients with chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC) who initiated enzalutamide and those who initiated abiraterone using the 100% Fee-For-Service Medicare claims data. The study will address the following objectives: Primary objective: To compare overall survival (OS) in patients with chemotherapy-naïve mCRPC who initiated enzalutamide vs. abiraterone Secondary objectives: To compare OS in patients with chemotherapy-naïve mCRPC who received only enzalutamide without any subsequent therapy vs. abiraterone without any subsequent therapy To compare treatment duration and time to subsequent therapy in chemotherapy-naïve mCRPC patients initiating enzalutamide vs. abiraterone

Official Title
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A Real-World Comparison of Clinical Outcomes in Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer (mCRPC) Patients Who Initiated Enzalutamide vs. Abiraterone Acetate (Abiraterone) in the 100% Medicare Fee-For-Service (FFS) Data (2009-2020)

Conditions
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Prostatic Neoplasms, Castration-Resistant

Intervention / Treatment
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* Drug: Enzalutamide
* Drug: Abiraterone acetate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male with ≥ 1 diagnosis claim for prostate cancer Have documented secondary metastasis code on or after the initial prostate cancer diagnosis Have initiated enzalutamide or abiraterone within 90 days prior to the metastasis date or on or after the metastasis date. The initiation date of enzalutamide or abiraterone will be defined as the index date. Have evidence of surgical or medical castration before the index date At least 18 years old at the index date Continuous eligibility for ≥ 12 months prior to the index date Exclusion Criteria: Received chemotherapy, novel hormonal therapy, radium-223, or immunotherapy prior to the index date Had a prior history of other cancers

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

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 |
| --- | --- |
| Enzalutamide cohort<br>Patients with mCRPC initiating enzalutamide | Drug: Enzalutamide<br>* As provided in real-world setting<br>* Other names: Xtandi;|
| Abiraterone cohort<br>Patients with mCRPC initiating abiraterone | Drug: Abiraterone acetate<br>* As provided in real-world setting<br>* Other names: Yonsa, Zytiga;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall survival | Overall survival (OS) will be defined as the time from the initiation of enzalutamide or abiraterone to the date of death. | Up to approximately 76 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall survival among patients without subsequent therapy | Overall survival (OS) among the subgroup of patients who received only enzalutamide without any subsequent therapy or received only abiraterone without any subsequent therapy. OS will be defined as the time from the initiation of enzalutamide or abiraterone (i.e., index date) to the date of death. | Up to approximately 76 months | 
| Treatment duration | Treatment duration will be defined as the time from the initiation of enzalutamide or abiraterone to the discontinuation date. Discontinuation will be defined as the earliest of 1) death, 2) last observed administration plus day of supply associated with last administration, or 3) day before the start of next line of therapy. | Up to approximately 76 months | 
| Time to subsequent therapy | Time to subsequent therapy will be defined as the time from the initiation of enzalutamide or abiraterone to the start of next line of therapy. | Up to approximately 76 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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OS, metastatic castration-resistant prostate cancer, mCRPC, enzalutamide, abiraterone, overall survival, treatment duration