Prostatic Neoplasms, Castration-Resistant
Conditions
Keywords
metastatic castration-resistant prostate cancer, mCRPC, enzalutamide, abiraterone, overall survival, OS, treatment duration
Brief summary
The purpose of this real-world study is to learn about the effects of 2 study medicines called enzalutamide and abiraterone used to treat metastatic castration-resistant prostate cancer (mCRPC). Prostate cancer is one of the most common cancers in men. The prostate is a gland in the male body that helps make semen. Most prostate cancers need male sex hormones, such as testosterone, to grow. Prostate cancer that keeps growing even when the amount of testosterone in the body is reduced to very low levels is known as "castration-resistant". Metastatic cancer is a cancer that has spread to other parts of the body. This is a real-world study, not a clinical trial. This means that researchers will look at what happens when men receive the treatments prescribed by their own doctor as part of their usual healthcare treatment. In this study, researchers will use information from the Flatiron Electronic Health Record (EHR) database. The study will include patients' information from the database for men who: * Were confirmed by medical tests to have mCRPC * Started first-line treatment with enzalutamide or abiraterone (index date) for mCRPC * Had not received chemotherapy treatment before index date * Were 18 years of age or older on index date Men who are part of this study will receive enzalutamide or abiraterone as part of their usual treatment for mCRPC. We will compare the following between men receiving enzalutamide and men receiving abiraterone: * time from treatment start until death, * treatment duration, and * time to next treatment. This study will use patient information from the database until the end of information that is available.
Interventions
DRUGEnzalutamide
As provided in real-world setting
DRUGAbiraterone acetate
As provided in real-world setting
Sponsors
Pfizer
Astellas Pharma Inc
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Male with metastatic prostate cancer diagnosis and abstracted castration-resistant prostate cancer diagnosis * Initiated enzalutamide or abiraterone within 14 days prior to or after the metastatic castration-resistant prostate cancer diagnosis. The initiation date of enzalutamide or abiraterone will be defined as the index date. * At least 18 years old at the index date
Exclusion criteria
* Received chemotherapy, novel hormonal therapy, radium-223, olaparib/rucaparib, or immunotherapy prior to the index date * Had a prior history of other cancers
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Overall Survival (OS): Adjusted Using Inverse Probability Treatment Weighting (IPTW) | From index date to date of death or censoring date, whichever occurred first (approximately 104.7 months); retrospective data retrieved and evaluated during approximately 18.7 months | OS was defined as the time from the initiation of enzalutamide or abiraterone (i.e., index date) to the date of death. Participants who did not die during this period were censored at their last available follow-up, which was defined as the earlier of end of data availability or last participant contact. Index date was defined as the date of initiation of enzalutamide or abiraterone and their index date was required to occur during the index period. Kaplan-Meier (weighted) method was used for analysis. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| OS Without Subsequent Therapy: Adjusted Using IPTW | From index date to date of death or censoring date, whichever occurred first (approximately 104.7 months); retrospective data retrieved and evaluated during approximately 18.7 months | OS was defined as the time from the initiation of enzalutamide or abiraterone (i.e., index date) to the date of death. Participants who did not die during this period were censored at their last available follow-up, which was defined as the earlier of end of data availability or last participant contact. Index date was defined as the date of initiation of enzalutamide or abiraterone and their index date was required to occur during the index period. OS of only those participants who initiated abiraterone and enzalutamide on the index date and did not receive subsequent systemic anti-neoplastic therapy were reported in this outcome measure. Kaplan-Meier (weighted) method was used for analysis. |
| Time to Treatment Discontinuation (TTD): Adjusted Using IPTW | From index date to date of treatment discontinuation or censoring date, whichever occurred first (approximately 104.7 months); retrospective data retrieved and evaluated during approximately 18.7 months | Treatment duration of the index treatment was defined as the time from the initiation of enzalutamide or abiraterone (i.e., index date) to the discontinuation date. Index date was defined as the date of initiation of enzalutamide or abiraterone and their index date was required to occur during the index period. Discontinuation was defined as the earliest of 1) death, 2) abstracted end date for last enzalutamide or abiraterone drug episode that started within the index treatment line of therapy (LOT) (drug episodes for abstracted oral therapies from the Flatiron Drug Episode table), or 3) day before the start of next LOT. Participants who did not discontinue were censored at their last available follow-up, which was defined as the earlier of end of data availability or last participant contact. Kaplan-Meier (weighted) method was used for analysis. |
| Time to Subsequent Therapy (TTST): Adjusted Using IPTW | From index date to date of start of next LOT or censoring date, whichever occurred first (approximately 104.7 months); retrospective data retrieved and evaluated during approximately 18.7 months | TTST was defined as the time from the initiation of enzalutamide or abiraterone (i.e., index date) to the start of next LOT. Index date was defined as the date of initiation of enzalutamide or abiraterone and their index date was required to occur during the index period. Participants who did not start a new LOT were censored at their last available follow-up, which was defined as the earliest of 1) death, 2) end of data availability or 3) last participant contact. Kaplan-Meier (weighted) method was used for analysis. |
Countries
United States
Contacts
STUDY_DIRECTORPfizer CT.gov Call Center
Pfizer
Participant flow
Recruitment details
Data of eligible participants with metastatic castration-resistant prostate cancer (mCRPC), who initiated abiraterone or enzalutamide from 10-Sep-2014 to 30-Jun-2020 (approximately 69.7 months = index period) were retrieved from Flatiron electronic health record (EHR) database from 10-Sep-2014 to 31-May-2023 (approximately 104.7 months = data collection period).
Pre-assignment details
Retrospective data were retrieved and evaluated per objectives of this observational study from 24-Jul-2023 to 14-Feb-2025 (approximately 18.7 months).
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 74.9 Years STANDARD_DEVIATION 8 |
| Race/Ethnicity, Customized Asian | 22 Participants |
| Race/Ethnicity, Customized Black | 277 Participants |
| Race/Ethnicity, Customized Hispanic or Latino | 81 Participants |
| Race/Ethnicity, Customized Other race | 372 Participants |
| Race/Ethnicity, Customized Unknown | 90 Participants |
| Race/Ethnicity, Customized White | 1704 Participants |
| Sex: Female, Male Female | 0 Participants |
| Sex: Female, Male Male | 2731 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 1,007 / 1,316 | 1,036 / 1,415 |
| other Total, other adverse events | 0 / 0 | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 | 0 / 0 |
Outcome results
None listed