Trial Outcomes & Findings for Enzalutamide vs. Abiraterone in Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer (mCRPC) (NCT NCT05520138)

NCT ID: NCT05520138

Last Updated: 2024-09-27

Results Overview

OS (time to death) 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 were censored at their last available follow-up, which was defined as the earlier of disenrollment from Medicare or end of data availability. Kaplan-Meier method was used for analysis.

Recruitment status

COMPLETED

Target enrollment

5506 participants

Primary outcome timeframe

From index date to date of death or censoring date, whichever occurred first (from 10-Sep-2014 to 31-Dec-2020, approximately 76 months); retrospective data extracted and evaluated from study start date and until study completion (approximately 10 months)

Results posted on

2024-09-27

Participant Flow

Data of participants- with chemotherapy naive metastatic castration-resistant prostate cancer (mCRPC), who initiated abiraterone or enzalutamide during the index period of 10 September 2014 to 31 May 2017 (approximately 33 months)- were included in this study. Data was retrieved from 100% Medicare Fee-For-Service (FFS). Retrospective data extracted and evaluated from study start date and until study completion (approximately 10 months) of this retrospective observational study.

Participant milestones

Participant milestones
Measure
Abiraterone
Participants with mCRPC who initiated abiraterone during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Enzalutamide
Participants with mCRPC who initiated enzalutamide during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Overall Study
STARTED
2911
2595
Overall Study
COMPLETED
2911
2595
Overall Study
NOT COMPLETED
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Abiraterone
n=2911 Participants
Participants with mCRPC who initiated abiraterone during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Enzalutamide
n=2595 Participants
Participants with mCRPC who initiated enzalutamide during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Total
n=5506 Participants
Total of all reporting groups
Age, Continuous
78.4 Years
STANDARD_DEVIATION 7.9 • n=5 Participants
78.6 Years
STANDARD_DEVIATION 8.2 • n=7 Participants
78.5 Years
STANDARD_DEVIATION 8.0 • n=5 Participants
Sex: Female, Male
Female
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Sex: Female, Male
Male
2911 Participants
n=5 Participants
2595 Participants
n=7 Participants
5506 Participants
n=5 Participants
Race/Ethnicity, Customized
Black
364 Participants
n=5 Participants
336 Participants
n=7 Participants
700 Participants
n=5 Participants
Race/Ethnicity, Customized
White, non-Hispanic
2273 Participants
n=5 Participants
2012 Participants
n=7 Participants
4285 Participants
n=5 Participants
Race/Ethnicity, Customized
Hispanic
148 Participants
n=5 Participants
134 Participants
n=7 Participants
282 Participants
n=5 Participants
Race/Ethnicity, Customized
Unknown or Others
126 Participants
n=5 Participants
113 Participants
n=7 Participants
239 Participants
n=5 Participants

PRIMARY outcome

Timeframe: From index date to date of death or censoring date, whichever occurred first (from 10-Sep-2014 to 31-Dec-2020, approximately 76 months); retrospective data extracted and evaluated from study start date and until study completion (approximately 10 months)

Population: Analysis population included all eligible participants whose medical records were retrieved and observed in this study. Here, ''Number of Participants Analyzed'' signifies number of participants evaluable for this outcome measure after adjusting for baseline confounders (demographics, clinical characteristics, prior treatments, comorbidities, medical resource use) using IPTW. Hence, numbers are different here from those presented in participant and baseline section.

OS (time to death) 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 were censored at their last available follow-up, which was defined as the earlier of disenrollment from Medicare or end of data availability. Kaplan-Meier method was used for analysis.

Outcome measures

Outcome measures
Measure
Abiraterone
n=2912 Participants
Participants with mCRPC who initiated abiraterone during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Enzalutamide
n=2591 Participants
Participants with mCRPC who initiated enzalutamide during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Overall Survival (OS): Inverse Probability Treatment Weighting (IPTW)
20.6 Months
Interval 19.7 to 21.4
22.5 Months
Interval 21.2 to 23.8

SECONDARY outcome

Timeframe: From index date to date of death or censoring date, whichever occurred first (from 10-Sep-2014 to 31-Dec-2020, approximately 76 months); retrospective data extracted and evaluated from study start date and until study completion (approximately 10 months)

Population: Analysis population included all eligible participants whose medical records were retrieved and observed in this study. Here, ''Number of Participants Analyzed'' signifies number of participants evaluable for this outcome measure after adjusting for baseline confounders (demographics, clinical characteristics, prior treatments, comorbidities, medical resource use) using IPTW. Hence, numbers are different here from those presented in participant and baseline section.

OS (time to death) 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 were censored at their last available follow-up, which was defined as the earlier of disenrollment from Medicare or end of data availability. Kaplan-Meier method was used for analysis.

Outcome measures

Outcome measures
Measure
Abiraterone
n=1168 Participants
Participants with mCRPC who initiated abiraterone during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Enzalutamide
n=1075 Participants
Participants with mCRPC who initiated enzalutamide during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
OS Among Participants Without Any Subsequent Therapy: IPTW
10.6 Months
Interval 9.6 to 11.7
13.6 Months
Interval 12.4 to 15.1

SECONDARY outcome

Timeframe: From index date to date of discontinuation event or censoring date, whichever occurred first(from 10-Sep-2014 to 31-Dec-2020, approximately 76months); retrospective data extracted and evaluated from start date and until completion(approximately 10months)

Population: Analysis population included all eligible participants whose medical records were retrieved and observed in this study. Here ''Number of Participants Analyzed'' signifies number of participants evaluable for this outcome measure after adjusting for baseline confounders (demographics, clinical characteristics, prior treatments, comorbidities, medical resource use) using IPTW. Hence, numbers are different here from those presented in participant and baseline section.

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. Discontinuation was 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. Death, a gap of 90 days or more after the last observed prescription date + day of supply, and initiation of next line of therapy was considered as discontinuation events. Participants who did not discontinue were censored at their last available follow-up, which was defined as the earlier of disenrollment from Medicare or end of data availability.

Outcome measures

Outcome measures
Measure
Abiraterone
n=2912 Participants
Participants with mCRPC who initiated abiraterone during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Enzalutamide
n=2591 Participants
Participants with mCRPC who initiated enzalutamide during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Treatment Duration: IPTW
6.7 Months
Interval 6.3 to 7.0
7.4 Months
Interval 7.0 to 7.9

SECONDARY outcome

Timeframe: From index date to start of next line of therapy (from 10-Sep-2014 to 31-Dec-2020, approximately 76 months); retrospective data extracted and evaluated from study start date and until study completion (approximately 10 months)

Population: Analysis population included all eligible participants whose medical records were retrieved and observed in this study. Here ''Number of Participants Analyzed'' signifies number of participants evaluable for this outcome measure after adjusting for baseline confounders (demographics, clinical characteristics, prior treatments, comorbidities, medical resource use) using IPTW. Hence, numbers are different here from those presented in participant and baseline section.

Time to subsequent therapy was defined as the time from the initiation of enzalutamide or abiraterone (i.e., index date) to the start of next line of therapy. Participants who did not start a new line of therapy were censored at their last available follow-up, which was defined as the earliest of 1) death, 2) disenrollment from Medicare, and 3) end of data availability.

Outcome measures

Outcome measures
Measure
Abiraterone
n=2912 Participants
Participants with mCRPC who initiated abiraterone during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Enzalutamide
n=2591 Participants
Participants with mCRPC who initiated enzalutamide during the index period in real-world setting and whose data were observed in the study, were included in this reporting group.
Time to Subsequent Therapy: IPTW
14.5 Months
Interval 13.4 to 15.4
16.7 Months
Interval 15.9 to 17.8

Adverse Events

Abiraterone

Serious events: 0 serious events
Other events: 0 other events
Deaths: 2523 deaths

Enzalutamide

Serious events: 0 serious events
Other events: 0 other events
Deaths: 2176 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Pfizer Inc.

Pfizer ClinicalTrials.gov Call Center

Phone: 1-800-718-1021

Results disclosure agreements

  • Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publications until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
  • Publication restrictions are in place

Restriction type: OTHER