Trial Outcomes & Findings for Testing the Effects of Low Dose Apalutamide on Prostate-Specific Antigen (PSA) Levels in Men Scheduled for Removal of the Prostate Gland (NCT NCT04530552)

Last Updated: 2026-02-03

Results Overview

The proportion of participants with \>= 25% decline in PSA levels (from baseline to end-of-intervention) will be reported along with the 97.5% credible interval for the response rate based on the posterior distribution of the response rate derived from a non-informative prior for the response rate, which is consistent with the Bayesian approach.

Recruitment status

ACTIVE_NOT_RECRUITING

Study phase

PHASE2

Target enrollment

34 participants

Primary outcome timeframe

Baseline to end-of-intervention (mean 4.8 weeks; up to 9 weeks)

Results posted on

2026-02-03

Participant Flow

All potential subjects were initially recruited into Cohort 1. Once it was determined that the dose would be de-escalated for the next phase of the trial, subsequent potential subjects were recruited into Cohort 2.

Participant milestones

Participant milestones
Measure	Cohort 1 60 mg apalutamide, 3x per week	Cohort 2 60 mg apalutamide, 1x per week
Overall Study STARTED	15	19
Overall Study Initiated Treatment	15	17
Overall Study COMPLETED	15	15
Overall Study NOT COMPLETED	0	4

Reasons for withdrawal

Reasons for withdrawal
Measure	Cohort 1 60 mg apalutamide, 3x per week	Cohort 2 60 mg apalutamide, 1x per week
Overall Study Physician Decision	0	1
Overall Study Withdrawal by Subject	0	1
Overall Study Adverse Event	0	1
Overall Study No surgery	0	1

Baseline Characteristics

Testing the Effects of Low Dose Apalutamide on Prostate-Specific Antigen (PSA) Levels in Men Scheduled for Removal of the Prostate Gland

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Cohort 1 n=15 Participants 60 mg apalutamide, 3x per week	Cohort 2 n=17 Participants 60 mg apalutamide, 1x per week	Total n=32 Participants Total of all reporting groups
Age, Continuous	70.1 years n=13 Participants	65.8 years n=15 Participants	68.1 years n=28 Participants
Sex: Female, Male Female	0 Participants n=13 Participants	0 Participants n=15 Participants	0 Participants n=28 Participants
Sex: Female, Male Male	15 Participants n=13 Participants	17 Participants n=15 Participants	32 Participants n=28 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=13 Participants	0 Participants n=15 Participants	0 Participants n=28 Participants
Race (NIH/OMB) Asian	1 Participants n=13 Participants	0 Participants n=15 Participants	1 Participants n=28 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=13 Participants	0 Participants n=15 Participants	0 Participants n=28 Participants
Race (NIH/OMB) Black or African American	1 Participants n=13 Participants	5 Participants n=15 Participants	6 Participants n=28 Participants
Race (NIH/OMB) White	12 Participants n=13 Participants	12 Participants n=15 Participants	24 Participants n=28 Participants
Race (NIH/OMB) More than one race	1 Participants n=13 Participants	0 Participants n=15 Participants	1 Participants n=28 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=13 Participants	0 Participants n=15 Participants	0 Participants n=28 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=13 Participants	1 Participants n=15 Participants	2 Participants n=28 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	14 Participants n=13 Participants	16 Participants n=15 Participants	30 Participants n=28 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=13 Participants	0 Participants n=15 Participants	0 Participants n=28 Participants
Prostate specific antigen (PSA)	6.3 ng/mL n=13 Participants	7.9 ng/mL n=15 Participants	6.4 ng/mL n=28 Participants

PRIMARY outcome

Timeframe: Baseline to end-of-intervention (mean 4.8 weeks; up to 9 weeks)

Outcome measures

Outcome measures
Measure	Cohort 1 n=15 Participants 60 mg apalutamide, 3x per week	Cohort 2 n=17 Participants 60 mg apalutamide, 1x per week
Change in Prostate Specific Antigen (PSA) Levels	10 Participants	7 Participants

SECONDARY outcome

Timeframe: End-of-intervention to post-operation (mean 2.7 days; up to 7 days)

Population: Missing testosterone data for one subject in Cohort 2

Mean change in testosterone from end-of-intervention to post-operation

Outcome measures

Outcome measures
Measure	Cohort 1 n=15 Participants 60 mg apalutamide, 3x per week	Cohort 2 n=16 Participants 60 mg apalutamide, 1x per week
Reversibility of Testosterone Levels	-136.1 ng/dL Standard Deviation 195.0	-80.5 ng/dL Standard Deviation 198.8

SECONDARY outcome

Timeframe: End-of-intervention (mean 4.8 weeks; up to 9 weeks)

Correlation between plasma apalutamide and percent change of PSA levels

Outcome measures

Outcome measures
Measure	Cohort 1 n=15 Participants 60 mg apalutamide, 3x per week	Cohort 2 n=17 Participants 60 mg apalutamide, 1x per week
Post-intervention Plasma Trough Apalutamide Concentrations	796.3 ng/mL Standard Deviation 250.5	212.4 ng/mL Standard Deviation 90.0

SECONDARY outcome

Timeframe: Baseline to end of intervention (mean 4.8 weeks; up to 9 weeks)

Population: Missing data for overall score for one subject in each cohort

Expanded Prostate Cancer Index Composite for Clinical Practice \[EPIC-CP\]. Higher scores indicate worse outcome (more symptoms). The minimum and maximum values for the total score are 0 to 60. A negative change indicates that the score decreased and therefore is a better outcome (reduced symptoms).

Outcome measures

Outcome measures
Measure	Cohort 1 n=14 Participants 60 mg apalutamide, 3x per week	Cohort 2 n=16 Participants 60 mg apalutamide, 1x per week
Health-related Quality of Life (HRQOL)	0.6 change in overall score Standard Deviation 5.3	-2.5 change in overall score Standard Deviation 6.9

OTHER_PRE_SPECIFIED outcome

Timeframe: Up to 7-14 days after prostate surgery

Changes (from most recent biopsy to prostatectomy) in the Gleason score of pre- and post-intervention tumor(s) with matched location will be assessed for each dose group. Linear mixed effects model with a random intercept accounting for within-subject dependence will be performed to compare the change in Gleason score of pre- and post-intervention tumor(s) with matched location since a participant can have more than one tumor. A 95% Cl will be reported for each of the two dose groups.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Up to 7-14 days after prostate surgery

CD8+, CD4+, and CD56+ positive cells in the prostate tissues will be assessed by immunohistochemistry. Changes (from most recent biopsy to prostatectomy) in these immune cells will be assessed for each dose group. Changes in immune cel infiltration will also be assessed in a subgroup of participants where materials are available from pre- and post-intervention tumors) with matched location. Changes (from most recent biopsy to prostatectomy) in these immune cells will be assessed for each dose group by paired t test. A 95% Cl will be reported for each of the two dose groups.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline, every 7-10 during study, within 3 days prior to surgery, and 7-14 days after surgery

Will be assessed by examining the associations between tobacco and alcohol consumption and the effects of apalutamide on the study endpoints.

Outcome measures

Outcome data not reported

Adverse Events

Cohort 1

Serious events: 0 serious events

Other events: 11 other events

Deaths: 0 deaths

Cohort 2

Serious events: 1 serious events

Other events: 13 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Cohort 1 n=15 participants at risk 60 mg apalutamide, 3x per week	Cohort 2 n=17 participants at risk 60 mg apalutamide, 1x per week
Nervous system disorders Stroke	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)

Other adverse events

Additional Information

Betsy Wertheim

University of Arizona

Phone: 5207771666

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Restriction type: LTE60

Measure	Cohort 1 n=15 participants at risk 60 mg apalutamide, 3x per week	Cohort 2 n=17 participants at risk 60 mg apalutamide, 1x per week
Reproductive system and breast disorders Gynecomastia	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Reproductive system and breast disorders Breast tenderness	13.3% 2/15 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Skin and subcutaneous tissue disorders Other, rash	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Skin and subcutaneous tissue disorders Photosensitivity	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Skin and subcutaneous tissue disorders Pruritus	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Vascular disorders Flushing	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Vascular disorders Hypertension	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Injury, poisoning and procedural complications Other, stingray wound	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Investigations Blood bicarbonate decreased	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Investigations Creatinine increased	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Investigations Platelet count decreased	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Nervous system disorders Headache	13.3% 2/15 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Investigations Thyroid stimulating hormone increased	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Investigations Weight loss	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Nervous system disorders Hypersomnia	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Metabolism and nutrition disorders Anorexia	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Nervous system disorders Parasthesia	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Psychiatric disorders Anxiety	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Metabolism and nutrition disorders Hyperglycemia	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Musculoskeletal and connective tissue disorders Arthralgia	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Psychiatric disorders Libido decreased	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Musculoskeletal and connective tissue disorders Back pain	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Musculoskeletal and connective tissue disorders Muscle cramp	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Renal and urinary disorders Hematuria	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Renal and urinary disorders Urinary retention	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Musculoskeletal and connective tissue disorders Muscle weakness lower limb	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Musculoskeletal and connective tissue disorders Myalgia	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Musculoskeletal and connective tissue disorders Pain in extremity	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Nervous system disorders Dizziness	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Abdominal pain	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Anal fissure	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Diarrhea	13.3% 2/15 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Dry mouth	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Mucositis oral	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Nausea	13.3% 2/15 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Oral dysesthesia	6.7% 1/15 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Other, bowel movement has green tint	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Toothache	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Gastrointestinal disorders Vomiting	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
General disorders Edema limbs	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
General disorders Fatigue	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
General disorders Gait disturbance	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
General disorders Other, increased thirst	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
General disorders Pain	6.7% 1/15 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)	0.00% 0/17 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Infections and infestations Herpes simplex reactivation	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Injury, poisoning and procedural complications Fall	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	11.8% 2/17 • Number of events 2 • From baseline to follow-up visit (7-14 days post-prostatectomy)
Cardiac disorders Ventricular arrhythmia	0.00% 0/15 • From baseline to follow-up visit (7-14 days post-prostatectomy)	5.9% 1/17 • Number of events 1 • From baseline to follow-up visit (7-14 days post-prostatectomy)