Trial Outcomes & Findings for A Study of Salvage Radiotherapy With or Without Enzalutamide in Recurrent Prostate Cancer Following Surgery (NCT NCT03809000)

Last Updated: 2025-12-30

Results Overview

Progression-free survival (PFS) is estimated by the Kaplan-Meier method. PFS time is measured from randomization to the date of first PFS failure (biochemical or clinical failure, initiation of new unplanned anticancer treatment, or death from any cause) or last known follow-up (censored). Analysis was to occur after progression or death was reported for 101 participants. Biochemical failure is defined as first post-RT detectable PSA (PSA ≥ 0.05). Clinical failure is defined as either a local, regional, or distant failure.

Recruitment status

ACTIVE_NOT_RECRUITING

Study phase

PHASE2

Target enrollment

188 participants

Primary outcome timeframe

From randomization to first failure or last known follow-up. Median follow-up time at the time of analysis was 33.1 months. The 1- and 2-year estimates are reported.

Results posted on

2025-12-30

Participant Flow

Participant milestones

Participant milestones
Measure	Salvage Radiation Therapy (SRT) + Standard Androgen Deprivation Therapy (ADT) Standard ADT: 24 months of gonadotropin-releasing hormone (GnRH) analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	Salvage Radiation Therapy + Enhanced ADT Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Overall Study STARTED	98	90
Overall Study Adverse Event Population	98	89
Overall Study COMPLETED	98	90
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

A Study of Salvage Radiotherapy With or Without Enzalutamide in Recurrent Prostate Cancer Following Surgery

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	Total n=188 Participants Total of all reporting groups
Age, Continuous	65 years n=174 Participants	63 years n=166 Participants	64 years n=167 Participants
Sex: Female, Male Female	0 Participants n=174 Participants	0 Participants n=166 Participants	0 Participants n=167 Participants
Sex: Female, Male Male	98 Participants n=174 Participants	90 Participants n=166 Participants	188 Participants n=167 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	8 Participants n=174 Participants	4 Participants n=166 Participants	12 Participants n=167 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	89 Participants n=174 Participants	82 Participants n=166 Participants	171 Participants n=167 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=174 Participants	4 Participants n=166 Participants	5 Participants n=167 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=174 Participants	0 Participants n=166 Participants	0 Participants n=167 Participants
Race (NIH/OMB) Asian	0 Participants n=174 Participants	3 Participants n=166 Participants	3 Participants n=167 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=174 Participants	0 Participants n=166 Participants	0 Participants n=167 Participants
Race (NIH/OMB) Black or African American	6 Participants n=174 Participants	15 Participants n=166 Participants	21 Participants n=167 Participants
Race (NIH/OMB) White	85 Participants n=174 Participants	67 Participants n=166 Participants	152 Participants n=167 Participants
Race (NIH/OMB) More than one race	2 Participants n=174 Participants	3 Participants n=166 Participants	5 Participants n=167 Participants
Race (NIH/OMB) Unknown or Not Reported	5 Participants n=174 Participants	2 Participants n=166 Participants	7 Participants n=167 Participants
Baseline PSA	0.565 ng/mL n=174 Participants	0.785 ng/mL n=166 Participants	0.605 ng/mL n=167 Participants
Pathologic T-Stage T2	21 Participants n=174 Participants	15 Participants n=166 Participants	36 Participants n=167 Participants
Pathologic T-Stage T3	2 Participants n=174 Participants	2 Participants n=166 Participants	4 Participants n=167 Participants
Pathologic T-Stage T3a	31 Participants n=174 Participants	28 Participants n=166 Participants	59 Participants n=167 Participants
Pathologic T-Stage T3b	42 Participants n=174 Participants	43 Participants n=166 Participants	85 Participants n=167 Participants
Pathologic T-Stage T4	2 Participants n=174 Participants	2 Participants n=166 Participants	4 Participants n=167 Participants
Pathologic N-Stage N0	63 Participants n=174 Participants	63 Participants n=166 Participants	126 Participants n=167 Participants
Pathologic N-Stage N1	20 Participants n=174 Participants	21 Participants n=166 Participants	41 Participants n=167 Participants
Pathologic N-Stage NX	15 Participants n=174 Participants	6 Participants n=166 Participants	21 Participants n=167 Participants
Gleason Score 6	1 Participants n=174 Participants	0 Participants n=166 Participants	1 Participants n=167 Participants
Gleason Score 7	39 Participants n=174 Participants	34 Participants n=166 Participants	73 Participants n=167 Participants
Gleason Score 8	11 Participants n=174 Participants	5 Participants n=166 Participants	16 Participants n=167 Participants
Gleason Score 9	46 Participants n=174 Participants	51 Participants n=166 Participants	97 Participants n=167 Participants
Gleason Score 10	1 Participants n=174 Participants	0 Participants n=166 Participants	1 Participants n=167 Participants
ECOG (Eastern Cooperative Oncology Group) Performance Status Scale 0	90 Participants n=174 Participants	77 Participants n=166 Participants	167 Participants n=167 Participants
ECOG (Eastern Cooperative Oncology Group) Performance Status Scale 1	8 Participants n=174 Participants	13 Participants n=166 Participants	21 Participants n=167 Participants
Number of aggressive features 1	30 Participants n=174 Participants	23 Participants n=166 Participants	53 Participants n=167 Participants
Number of aggressive features > 1	68 Participants n=174 Participants	67 Participants n=166 Participants	135 Participants n=167 Participants

PRIMARY outcome

Timeframe: From randomization to first failure or last known follow-up. Median follow-up time at the time of analysis was 33.1 months. The 1- and 2-year estimates are reported.

Population: Randomized participants

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants Alive Without Progression (Progression-Free Survival) 1 year	38.3 percentage of participants Interval 32.0 to 44.7	45.5 percentage of participants Interval 38.6 to 52.4
Percentage of Participants Alive Without Progression (Progression-Free Survival) 2 years	32.1 percentage of participants Interval 26.0 to 38.2	38.3 percentage of participants Interval 31.5 to 45.0

SECONDARY outcome

Timeframe: From randomization to first failure, competing event, or last known follow-up, whichever occurs first. Median follow-up time at the time of analysis was 33.1 months. The 1- and 2-year estimates are reported.

Population: Randomized participants

Biochemical failure is defined as the first detectable post-RT prostate-specific antigen (PSA) value (≥ 0.05) or the initiation of salvage hormone therapy. Failure rates are estimated using the cumulative incidence method, treating death as a competing risk, and otherwise censoring participants alive at time of analysis.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants With Biochemical Failure 1 year	61.7 percentage of participants Interval 51.1 to 70.6	54.6 percentage of participants Interval 43.4 to 64.5
Percentage of Participants With Biochemical Failure 2 years	67.9 percentage of participants Interval 57.5 to 76.3	60.6 percentage of participants Interval 49.3 to 70.2

SECONDARY outcome

Population: Randomized participants

Alternative biochemical failure is defined as first post-RT PSA ≥ 0.1 ng/mL or initiation of salvage hormone therapy. Failure rates are estimated using the cumulative incidence method, treating death as a competing risk, and otherwise censoring participants alive at time of analysis.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants With Alternative Biochemical Failure 1 year	35.9 percentage of participants Interval 26.5 to 45.5	31.4 percentage of participants Interval 21.9 to 41.3
Percentage of Participants With Alternative Biochemical Failure 2 years	45.4 percentage of participants Interval 35.2 to 55.0	39.9 percentage of participants Interval 29.4 to 50.2

SECONDARY outcome

Timeframe: From randomization to first failure, competing event, or last known follow-up, whichever occurs first. Median follow-up time at the time of analysis was 33.1 months.

Population: Randomized participants

Hormone-refractory disease is defined as three rises in PSA during salvage androgen deprivation, with the date determined as the midway date between the last non-rising PSA and the first of the three rises. Failure rates were to be estimated using the cumulative incidence method, treating death as a competing risk, and otherwise censoring participants alive at time of analysis, but for endpoints with \< 10 events overall, such as this one, only the counts of participants with the event are provided.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants With Hormone-refractory Disease	0 Participants	0 Participants

SECONDARY outcome

Timeframe: From randomization to first failure, competing event, or last known follow-up, whichever occurs first. Median follow-up time at the time of analysis was 33.1 months.

Population: Randomized participants

Distant failure is defined as first radiographic evidence of distant metastasis (e.g., bone scan, computed tomography (CT), magnetic resonance imaging (MRI)). Failure rates were to be estimated using the cumulative incidence method, treating death as a competing risk, and otherwise censoring participants alive at time of analysis, but for endpoints with \< 10 events overall, such as this one, only the counts of participants with the event are provided.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants With Distant Metastasis	6 Participants	1 Participants

SECONDARY outcome

Timeframe: From randomization to first failure, competing event, or last known follow-up, whichever occurs first. Median follow-up time at the time of analysis was 33.1 months.

Population: Randomized participants

Cause-specific mortality is defined as death due to prostate cancer. Failure rates were to be estimated using the cumulative incidence method, treating death as a competing risk, and otherwise censoring participants alive at time of analysis, but for endpoints with \< 10 events overall, such as this one, only the counts of participants with the event are provided.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants With Prostate Cancer Death	0 Participants	0 Participants

SECONDARY outcome

Timeframe: From randomization to death or last known follow-up, whichever occurs first. Median follow-up time at the time of analysis was 33.1 months.

Population: Randomized participants

Survival rates were to be estimated using the Kaplan-Meier method, censoring participants alive at time of analysis, but for endpoints with \< 10 events overall, such as this one, only counts are provided. In this case, the number of participants without event (death), which is the number of participants alive.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants Alive (Overall Survival)	96 Participants	90 Participants

SECONDARY outcome

Timeframe: Baseline and end of radiation treatment (RT). End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who consented to the quality of life study component and who have baseline and end of RT data

The EQ-5D-5L is a self-assessment questionnaire. The index score is computed from 5 items (mobility, self care, usual activities, pain/discomfort, anxiety/depression) each with 5 problem levels (1-none to 5-extreme). The 5-item index score is transformed into a utility score between 0 (worst health state) and 1 (best health state). Change score was calculated by subtracting baseline from later score, with a positive change score indicating improvement.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=77 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=67 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Change From Baseline to End of RT in the 5-level European Quality of Life Questionnaire (EQ-5D-5L) Index Score	0.0 score on a scale Standard Deviation 0.1	0.0 score on a scale Standard Deviation 0.1

SECONDARY outcome

Timeframe: Baseline and one year after end RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who consented to the quality of life study component and who have baseline and one year after end of RT data.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=71 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=64 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Change From Baseline to One Year After End of RT in the EQ-5D-5L Index Score	0.0 score on a scale Standard Deviation 0.1	0.0 score on a scale Standard Deviation 0.1

SECONDARY outcome

Timeframe: Baseline and two years after end of RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who consented to the quality of life study component and who have baseline and two year after end of RT data

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=64 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=62 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Change From Baseline to Two Years After End of RT in the EQ-5D-5L Index Score	0.0 score on a scale Standard Deviation 0.1	0.0 score on a scale Standard Deviation 0.1

SECONDARY outcome

Timeframe: Baseline and end of RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who consented to the quality of life study component and who have baseline and end of RT data

The PROMIS fatigue score measures self-reported fatigue symptoms over the past 7 days. Possible raw scores range from 29.4 to 83.2 (higher raw score indicating greater fatigue) and are converted into standardized T-scores (mean=50, standard deviation=10) with higher scores also indicating greater fatigue. Change score is calculated by subtracting baseline T-score from later T-score, with a positive change score indicating increased fatigue.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=74 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=64 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Change From Baseline to End of RT in the 7-item Patient Reported Outcomes Measurement Information System - Fatigue Short Form (PROMIS-F SF 7a) [PROMIS Fatigue Score]	3.4 score on a scale Standard Deviation 7.8	6.8 score on a scale Standard Deviation 6.4

SECONDARY outcome

Timeframe: Baseline and one year after end of RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who consented to the quality of life study component and who have baseline and end of RT data

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=72 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=61 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Change From Baseline to One Year After the End of RT in the 7-item Patient Reported Outcomes Measurement Information System - Fatigue Short Form (PROMIS-F SF 7a) [PROMIS Fatigue Score]	4.0 score on a scale Standard Deviation 7.4	7.0 score on a scale Standard Deviation 8.0

SECONDARY outcome

Timeframe: Baseline, two years after end of RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who consented to the quality-of-life study component and who have baseline and two years after end of RT data

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=66 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=60 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Change From Baseline to Two Years After the End of RT in the 7-item Patient Reported Outcomes Measurement Information System - Fatigue Short Form (PROMIS-F SF 7a) [PROMIS Fatigue Score]	4.0 score on a scale Standard Deviation 7.5	5.0 score on a scale Standard Deviation 7.8

SECONDARY outcome

Timeframe: From randomization to death or last known follow-up. Median follow-up time at the time of analysis was 33.1 months.

Population: Randomized participants who started protocol treatment and were assessed for adverse events.

Common Terminology Criteria for Adverse Events (version 5) grades adverse event severity as follows: 1 = mild, 2 = moderate, 3 = severe, 4 = life-threatening, 5 = death related to adverse event. Summary data is provided in this outcome measure; see Adverse Events Module for specific adverse event data.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=89 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Number of Participants by Highest Grade Adverse Event Reported CTCAE v5 Grade 2	38 Participants	32 Participants
Number of Participants by Highest Grade Adverse Event Reported CTCAE v5 Grade 3	27 Participants	39 Participants
Number of Participants by Highest Grade Adverse Event Reported CTCAE v5 Grade 4	6 Participants	6 Participants
Number of Participants by Highest Grade Adverse Event Reported CTCAE v5 Grade 5	0 Participants	0 Participants
Number of Participants by Highest Grade Adverse Event Reported CTCAE v5 None	8 Participants	3 Participants
Number of Participants by Highest Grade Adverse Event Reported CTCAE v5 Grade 1	19 Participants	9 Participants

SECONDARY outcome

Timeframe: From randomization to 30 days after the end of RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who started protocol treatment and were assessed for adverse events.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=89 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Number of Participants Any Adverse Event Occuring Within 30 Days Following the End of Treatment	86 Participants	83 Participants

SECONDARY outcome

Timeframe: From 31 days after the end of RT to death or last known follow-up. Median follow-up was 33.1 months. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants who started protocol treatment, were assessed for adverse events, and alive 30 days after radiation therapy ended.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=89 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Number of Participants With Any Grade 3+ Adverse Event Occuring After 30 Days Following the End of RT	27 Participants	30 Participants

SECONDARY outcome

Timeframe: End of RT, one and two years after the end of RT. End of RT can vary greatly depending on when it starts, which can be from 0 to 70 days from the start of ADT, and lasting 7-8 weeks.

Population: Randomized participants with PRO-CTCAE data.

PRO-CTCAE is a patient-reported outcome (PRO) measurement system developed to evaluate symptomatic toxicity in patients on cancer clinical trials, asking the patient about experience over the last seven days. Scores may reflect worst severity of the symptom (0=None, 1=Mild, 2=Moderate, 3=Severe, and 4=Very severe), frequency of the symptom (0=Never, 1=Rarely, 2=Occasionally, 3=Frequently, 4=Almost constantly), or the symptom's interference with one's "usual or daily activities" (0=Not at all, 1=A little bit, 2=Somewhat, 3=Quite a bit, 4=Very much). The symptom row title will indicate "Severity", "Frequency", or "Interference". All scores are compared between arms; statistical analysis results are entered for p-values \< 0.05.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=96 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=87 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Headache Severity	5 Participants	9 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Fatigue Severity	29 Participants	31 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Frequent Urination Interference	25 Participants	24 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Urine Control Loss Frequency	39 Participants	39 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Pain Frequency	35 Participants	33 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Taste Changes Severity	3 Participants	8 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Decreased Appetite Severity	2 Participants	6 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Decreased Appetite Interference	2 Participants	4 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Nausea Frequency	8 Participants	8 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Nausea Severity	7 Participants	3 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Constipation Severity	13 Participants	9 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Loose Stool Frequency	30 Participants	19 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Abdominal Pain Frequency	19 Participants	14 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Abdominal Pain Severity	13 Participants	9 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Abdominal Pain Interference	10 Participants	7 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Bowel Movement Control Frequency	9 Participants	5 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Bowel Movement Control Interference	7 Participants	5 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Racing Heartbeat Frequency	5 Participants	6 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Racing Heartbeat Severity	3 Participants	1 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Itchy Skin Severity	10 Participants	3 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Concentration Problems Severity	9 Participants	11 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Concentration Problems Interference	12 Participants	11 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Memory Problems Severity	7 Participants	11 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Memory Problems Interference	8 Participants	11 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Headache Frequency	12 Participants	9 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Headache Interference	5 Participants	6 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Fatigue Interference	31 Participants	34 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Pain with Urination Severity	4 Participants	6 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Urinary Urgency Frequency	38 Participants	37 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Urinary Urgency Interference	23 Participants	25 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Frequent Urination Frequency	46 Participants	45 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Urine Control Loss Interference	22 Participants	28 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Erection Difficulty Severity	40 Participants	24 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Ejaculation Problems Frequency	26 Participants	18 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Decreased Sexual Interest Severity	42 Participants	33 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Breast Tenderness Severity	7 Participants	7 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Hot Flashes Frequency	56 Participants	63 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Hot Flashes Severity	32 Participants	44 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Pain Severity	21 Participants	23 Participants
Number of Participants With Post-baseline Patient-reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Scores ≥ 3 Pain Interference	16 Participants	23 Participants

POST_HOC outcome

Timeframe: From randomization to first failure or last known follow-up. Medium follow-up time at the time of analysis was 33.1 months. The 1- and 2-year estimates are reported.

Population: Randomized participants

Progression-free survival (PFS) is estimated by the Kaplan-Meier method. PFS time is measured from randomization to the date of first PFS failure (biochemical or clinical failure, initiation of new unplanned anticancer treatment, or death from any cause) or last known follow-up (censored). Analysis was to occur after progression or death was reported for 101 participants. Biochemical failure is defined as first post-RT PSA ≥ 0.2. Clinical failure is defined as either a local, regional, or distant failure.

Outcome measures

Outcome measures
Measure	SRT + Standard ADT n=98 Participants Standard ADT: 24 months of GnRH analog (any formulation) with optional 1-4 months of bicalutamide (50 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.	SRT + Enhanced ADT n=90 Participants Enhanced ADT: 24 months of GnRH analog (any formulation) with 24 months of enzalutamide (160 mg/day). SRT: Starting within 0-70 days of initiation of GnRH analog, 66.6-70.2 Gy as 1.8 Gy/fraction in 37-39 fractions or 66.0-70.0 Gy as 2.0 Gy/fraction in 33-35 fractions lasting approximately 7-8 weeks, and optional lymph node boost.
Percentage of Participants Alive Without Progression (Progression-Free Survival) [Alternate Definition] 2 years	78.8 percentage of participants Interval 73.4 to 84.2	88.3 percentage of participants Interval 83.8 to 92.7
Percentage of Participants Alive Without Progression (Progression-Free Survival) [Alternate Definition] 1 year	87.5 percentage of participants Interval 83.2 to 91.8	91.9 percentage of participants Interval 88.1 to 95.6

Adverse Events

SRT + Standard ADT

Serious events: 11 serious events

Other events: 89 other events

Deaths: 2 deaths

SRT + Enhanced ADT

Serious events: 17 serious events

Other events: 87 other events

Deaths: 0 deaths

Serious adverse events

Other adverse events

Additional Information

Wendy Seiferheld

American College of Radiology

Phone: 2155743208

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee PI's are required to abide by the sponsor's publication guidelines which require review by coauthors and subsequent review and approval by the sponsor.
Publication restrictions are in place

Restriction type: OTHER