Trial Outcomes & Findings for Efficacy & Safety Study of Pregabalin to Treat Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) (NCT NCT00371033)

Last Updated: 2025-09-22

Results Overview

Decrease (improvement) in the National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) score of at least 6 points from baseline to week 6. The NIH-CPSI measures the 3 key domains of CP/CPPS: pain (location, frequency, and severity; possible score, 0-21), urinary symptoms (irritative and obstructive; possible score, 0-10), and impact/quality of life (possible score, 0-12), for a total possible score of 0 to 43. A 6-point decrease in NIHCPSI score has been shown to be clinically perceptible in previous clinical trials of men with CP/CPPS.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

324 participants

Primary outcome timeframe

Baseline and 6 weeks

Results posted on

2025-09-22

Participant Flow

Participant milestones

Participant milestones
Measure	1-Pregabalin Men were randomly assigned to receive pregabalin or placebo in a 2:1 ratio and were treated for 6 weeks. Treatment dosage was escalated as follows: 150 mg/d (50 mg orally 3 times daily) for 2 weeks, then 300 mg/d (100 mg orally 3 times daily) for 2 weeks, and then 600 mg/d (200 mg orally 3 times daily) for 2 weeks. Men assigned to receive placebo underwent a similar escalation in the number of capsules prescribed.	2-Placebo Men were randomly assigned to receive pregabalin or an identical placebo in a 2:1 ratio and were treated for 6 weeks. Treatment dosage was escalated as follows: 150 mg/d (50 mg orally 3 times daily) for 2 weeks, then 300 mg/d (100 mg orally 3 times daily) for 2 weeks, and then 600 mg/d (200 mg orally 3 times daily) for 2 weeks. Men assigned to receive placebo underwent a similar escalation in the number of capsules prescribed.
Overall Study STARTED	218	106
Overall Study COMPLETED	210	103
Overall Study NOT COMPLETED	8	3

Reasons for withdrawal

Reasons for withdrawal
Measure	1-Pregabalin Men were randomly assigned to receive pregabalin or placebo in a 2:1 ratio and were treated for 6 weeks. Treatment dosage was escalated as follows: 150 mg/d (50 mg orally 3 times daily) for 2 weeks, then 300 mg/d (100 mg orally 3 times daily) for 2 weeks, and then 600 mg/d (200 mg orally 3 times daily) for 2 weeks. Men assigned to receive placebo underwent a similar escalation in the number of capsules prescribed.	2-Placebo Men were randomly assigned to receive pregabalin or an identical placebo in a 2:1 ratio and were treated for 6 weeks. Treatment dosage was escalated as follows: 150 mg/d (50 mg orally 3 times daily) for 2 weeks, then 300 mg/d (100 mg orally 3 times daily) for 2 weeks, and then 600 mg/d (200 mg orally 3 times daily) for 2 weeks. Men assigned to receive placebo underwent a similar escalation in the number of capsules prescribed.
Overall Study Lost to Follow-up	3	2
Overall Study No longer interested	2	0
Overall Study Uknown	3	1

Baseline Characteristics

Based on evaluable patient data

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	1-Pregabalin n=216 Participants Men were randomly assigned to receive pregabalin or placebo in a 2:1 ratio and were treated for 6 weeks. Treatment dosage was escalated as follows: 150 mg/d (50 mg orally 3 times daily) for 2 weeks, then 300 mg/d (100 mg orally 3 times daily) for 2 weeks, and then 600 mg/d (200 mg orally 3 times daily) for 2 weeks. Men assigned to receive placebo underwent a similar escalation in the number of capsules prescribed.	2-Placebo n=103 Participants Men were randomly assigned to receive pregabalin or an identical placebo in a 2:1 ratio and were treated for 6 weeks. Treatment dosage was escalated as follows: 150 mg/d (50 mg orally 3 times daily) for 2 weeks, then 300 mg/d (100 mg orally 3 times daily) for 2 weeks, and then 600 mg/d (200 mg orally 3 times daily) for 2 weeks. Men assigned to receive placebo underwent a similar escalation in the number of capsules prescribed.	Total n=319 Participants Total of all reporting groups
Age, Continuous	48.0 years STANDARD_DEVIATION 13.0 • n=216 Participants	45.2 years STANDARD_DEVIATION 12.2 • n=103 Participants	47.0 years STANDARD_DEVIATION 13.1 • n=319 Participants
Sex: Female, Male Female	0 Participants n=216 Participants	0 Participants n=103 Participants	0 Participants n=319 Participants
Sex: Female, Male Male	216 Participants n=216 Participants	103 Participants n=103 Participants	319 Participants n=319 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=216 Participants	3 Participants n=103 Participants	4 Participants n=319 Participants
Race (NIH/OMB) Asian	0 Participants n=216 Participants	4 Participants n=103 Participants	4 Participants n=319 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=216 Participants	1 Participants n=103 Participants	1 Participants n=319 Participants
Race (NIH/OMB) Black or African American	24 Participants n=216 Participants	14 Participants n=103 Participants	38 Participants n=319 Participants
Race (NIH/OMB) White	178 Participants n=216 Participants	75 Participants n=103 Participants	253 Participants n=319 Participants
Race (NIH/OMB) More than one race	2 Participants n=216 Participants	4 Participants n=103 Participants	6 Participants n=319 Participants
Race (NIH/OMB) Unknown or Not Reported	11 Participants n=216 Participants	2 Participants n=103 Participants	13 Participants n=319 Participants
NIH-CPSI total score (possible score, 0-43)	26.2 units on a scale STANDARD_DEVIATION 5.6 • n=216 Participants	25.9 units on a scale STANDARD_DEVIATION 6.1 • n=103 Participants	26.1 units on a scale STANDARD_DEVIATION 5.7 • n=319 Participants
NIH-CPSI pain subscore (possible score, 0-21)	12.3 units on a scale STANDARD_DEVIATION 3.0 • n=216 Participants	12.4 units on a scale STANDARD_DEVIATION 3.1 • n=103 Participants	12.4 units on a scale STANDARD_DEVIATION 3.0 • n=319 Participants
NIH-CPSI urinary symptoms subscore (possible score, 0-10)	4.9 units on a scale STANDARD_DEVIATION 2.7 • n=216 Participants	4.7 units on a scale STANDARD_DEVIATION 2.7 • n=103 Participants	4.8 units on a scale STANDARD_DEVIATION 2.7 • n=319 Participants
NIH-CPSI QOL subscore (possible score, 0-12)	8.9 units on a scale STANDARD_DEVIATION 2.0 • n=216 Participants	8.9 units on a scale STANDARD_DEVIATION 2.0 • n=103 Participants	8.9 units on a scale STANDARD_DEVIATION 2.0 • n=319 Participants
SF-12 PCS score (possible score, 0-100)	44.9 units on a scale STANDARD_DEVIATION 10.1 • n=213 Participants • Based on evaluable patient data	43.9 units on a scale STANDARD_DEVIATION 10.3 • n=102 Participants • Based on evaluable patient data	44.6 units on a scale STANDARD_DEVIATION 10.2 • n=315 Participants • Based on evaluable patient data
SF-12 MCS score (possible score, 0-100)	41.8 units on a scale STANDARD_DEVIATION 10.6 • n=213 Participants • Based on evaluable patient data	42.8 units on a scale STANDARD_DEVIATION 10.6 • n=102 Participants • Based on evaluable patient data	42.1 units on a scale STANDARD_DEVIATION 10.6 • n=315 Participants • Based on evaluable patient data

PRIMARY outcome

Timeframe: Baseline and 6 weeks

Outcome measures

Outcome measures
Measure	1-Pregabalin n=218 Participants Randomized to Pregabalin	2-Placebo n=106 Participants Randomized to placebo
Decrease in the NIH-CPSI Total Score by at Least 6 Points	103 Participants	38 Participants

SECONDARY outcome

Timeframe: 6 weeks

Population: The overall number of participants analyzed in the secondary outcome measures were 210 for the pregabalin arm and 103 for the placebo arm.

The National Institutes of Health -Chronic Prostatitis Symptom Index (NIH-CPSI) measures the 3 key domains of Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS): pain (location, frequency, and severity; possible score, 0-21), urinary symptoms (irritative and obstructive; possible score, 0-10), and impact/quality of life (possible score, 0-12), for a total possible score of 0 to 43. A higher score indicates more severe symptoms. A 6-point decrease in NIHCPSI score has been shown to be clinically perceptible in previous clinical trials of men with CP/CPPS.

Outcome measures

Outcome measures
Measure	1-Pregabalin n=210 Participants Randomized to Pregabalin	2-Placebo n=103 Participants Randomized to placebo
Subscales of the NIH-CPSI Total score	19.7 units on the NIH-CPSI scale Standard Deviation 8.5	21.6 units on the NIH-CPSI scale Standard Deviation 8.9
Subscales of the NIH-CPSI Pain domain score	9.1 units on the NIH-CPSI scale Standard Deviation 3.1	10.1 units on the NIH-CPSI scale Standard Deviation 4.7
Subscales of the NIH-CPSI Urinary symptoms domain score	3.7 units on the NIH-CPSI scale Standard Deviation 2.6	4.0 units on the NIH-CPSI scale Standard Deviation 2.7
Subscales of the NIH-CPSI Quality of life domain	6.9 units on the NIH-CPSI scale Standard Deviation 2.9	7.4 units on the NIH-CPSI scale Standard Deviation 3.1

SECONDARY outcome

Timeframe: 6 weeks

The GRA is a 7-question patient self-reported assessment that measures perception of change in symptoms (improvement, no change, or deterioration). The responses are centered at zero (no change in symptoms). Men who reported that they were moderately or markedly improved on a 7-point GRA at the end of the study were identified as treatment responders.

Outcome measures

Outcome measures
Measure	1-Pregabalin n=218 Participants Randomized to Pregabalin	2-Placebo n=106 Participants Randomized to placebo
Moderately or Markedly Improve on Global Response Assessment (GRA)	68 Participants	20 Participants

SECONDARY outcome

Timeframe: 6 weeks

Hospital Anxiety and Depression Scale (HADS) (range, 0-42, with higher scores indicating greater anxiety and depression)

Outcome measures

Outcome measures
Measure	1-Pregabalin n=210 Participants Randomized to Pregabalin	2-Placebo n=103 Participants Randomized to placebo
Hospital Anxiety & Depression Scale	12.4 units on a scale Standard Deviation 7.8	12.2 units on a scale Standard Deviation 7.8

SECONDARY outcome

Timeframe: 6 weeks

The McGill Pain Questionnaire (MPQ) evaluates the quality of pain as well as the intensity of pain. The McGill Pain Questionnaire ranges from 0-45 for a total pain score, and is the sum of a sensory subscore of 0-33 and affective subscore of 0-12. Higher scores indicate greater pain.

Outcome measures

Outcome measures
Measure	1-Pregabalin n=210 Participants Randomized to Pregabalin	2-Placebo n=103 Participants Randomized to placebo
McGill Pain Questionnaire	9.6 units on a scale Standard Deviation 8.8	12.4 units on a scale Standard Deviation 9.1

SECONDARY outcome

Timeframe: 6 weeks

Medical Outcomes Study 12-Item Short Form Health Survey (SF-12) (range, 0-100 for the Physical \[PCS\] and Mental \[MCS\] Component Summary scores, with the mean set at 50 and higher scores indicating better quality of life)

Outcome measures

Outcome measures
Measure	1-Pregabalin n=210 Participants Randomized to Pregabalin	2-Placebo n=103 Participants Randomized to placebo
Medical Outcomes Study Short Form 12 Physical [PCS] Component Summary	46.9 units on a scale Standard Deviation 10.1	44.3 units on a scale Standard Deviation 10.6
Medical Outcomes Study Short Form 12 Mental [MCS] Component Summary	45.0 units on a scale Standard Deviation 11.2	44.6 units on a scale Standard Deviation 10.6

SECONDARY outcome

Timeframe: 6 weeks

Sexual Health Inventory for Men (SHIM) (range, 1-25, with higher scores indicating better sexual function)

Outcome measures

Outcome measures
Measure	1-Pregabalin n=210 Participants Randomized to Pregabalin	2-Placebo n=103 Participants Randomized to placebo
Sexual Health Inventory for Men	16.4 units on a scale Standard Deviation 8.4	17.2 units on a scale Standard Deviation 7.8

Adverse Events

1-Pregabalin

Serious events: 0 serious events

Other events: 129 other events

Deaths: 0 deaths

2-Placebo

Serious events: 0 serious events

Other events: 62 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	1-Pregabalin n=218 participants at risk Randomized to Pregabalin	2-Placebo n=106 participants at risk Randomized to placebo
General disorders Pain	17.4% 38/218 • Number of events 38 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.	33.0% 35/106 • Number of events 38 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.
General disorders Constitutional symptoms	24.3% 53/218 • Number of events 53 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.	20.8% 22/106 • Number of events 22 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.
Nervous system disorders Neurologic symptoms	18.3% 40/218 • Number of events 40 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.	18.9% 20/106 • Number of events 20 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.
Gastrointestinal disorders Gastrointestinal disturbance	18.3% 40/218 • Number of events 40 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.	18.9% 20/106 • Number of events 20 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.
Eye disorders Ocular/visual symptoms	6.9% 15/218 • Number of events 15 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.	2.8% 3/106 • Number of events 3 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.
Renal and urinary disorders Renal/genitourinary symptoms	5.5% 12/218 • Number of events 12 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.	1.9% 2/106 • Number of events 2 • 6 weeks Final Adverse Events were reported by arm. They included all AEs by type, regardless of their relationship to study drug. Patients are counted once in each category and included in the column relating to their worst toxicity grade. Patients may have had events in more than one body system category. An adverse event is not counted if the same event is observed at baseline with an equal or greater toxicity grade.

Additional Information

J. Richard Landis, PhD

University of Pennsylvania

Phone: 215-573-4922

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place