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CompletedNCT00991276Updated Feb 15, 2021Results posted

Polysomnography Study Of Pregabalin And Pramipexole Versus Placebo In Patients With Restless Legs Syndrome And Associated Sleep Disturbance

A Phase 3 interventional study of pregabalin and placebo in Restless Legs Syndrome, sponsored by Pfizer's Upjohn has merged with Mylan to form Viatris Inc.. Completed at 41 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2021-02-15.

Sponsored by Pfizer's Upjohn has merged with Mylan to form Viatris Inc. · Phase 3, Interventional, and Treatment

Phase
Phase 3
Study type
Interventional
Enrollment
85
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The purpose of this study is to assess the efficacy and safety of pregabalin and pramipexole versus placebo in the treatment of restless legs syndrome and associated sleep disturbance.

02

Conditions studied

  • Restless Legs Syndrome

Keywords

  • restless legs syndrome RLS polysomnography PSG sleep disturbance patient reported outcome
03

In context

Psychomotor Agitation

500 studies on the registry are indexed under Psychomotor Agitation; 55 are open to participants now.

This study's enrollment of 85 is close to the median of 90 across 413 interventional studies indexed under Psychomotor Agitation.

Browse Psychomotor Agitation studies →

Lead sponsor

Pfizer's Upjohn has merged with Mylan to form Viatris Inc. is the lead sponsor of 431 studies on the registry; none are open to participants now.

Of its 9 completed or terminated interventional studies of FDA-regulated products, 8 (89%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Diagnosis of restless legs syndrome with a total score of 15 or more points on the International RLS rating scale (IRLS).
  • RLS symptoms interfering with sleep on 3 or more nights per week for at least 6 months.
  • PSG confirmation of WASO of at least 60 min, PLMI of 10 or more, and total sleep time of at least 3 hrs and less than 6.5 hrs.

Exclusion criteria

Exclusion Criteria:

  • Secondary RLS.
  • Daytime RLS symptoms requiring treatment.
  • Primary sleep disorder.
  • Sleep apnea.
  • Night or shift work.
  • Concurrent medical disorder that could interfere with efficacy assessment or present a safety concern.
  • Pregnant or lactating women.
  • Women of child-bearing potential not using acceptable method of birth control.
  • Use of prohibited medication.
05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
85 participants (actual)

Study arms

  • Experimental
    pregabalin

    Drug: pregabalin

  • Placebo comparator
    placebo

    Drug: placebo

  • Active comparator
    pramipexole

    Drug: pramipexole

Interventions

  • Drugpregabalin

    capsules; 300 mg once-per-day; 4 weeks of treatment

    Also known as: Lyrica

  • Drugplacebo

    capsules; 0 mg once-per-day; 4 weeks of treatment

  • Drugpramipexole

    capsules; 0.5 mg once-per-day; 4 weeks of treatment

    Also known as: Mirapex

06

What researchers measure

Primary outcomes

  1. Wake After Sleep Onset (WASO)

    WASO as determined by Polysomnography (PSG) was time spent awake from sleep onset to final awakening. WASO= Wake Time During Sleep \[WTDS\] epochs + Wake Time After Sleep \[WTAS\] epochs)/2. WTDS: number of wake epochs (30 seconds of PSG recording) after onset of persistent sleep and prior to final awakening or end of 8-hour recording/2 and WTAS: number of wake epochs after final awakening until end of the 8-hour recording/2. WASO was measured on 2 consecutive days within a period. Arithmetic mean of WASO of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or Early Termination (ET)

Secondary outcomes

  1. Periodic Limb Movement Arousal Index (PLMAI)

    PLMAI, as determined by PSG was number of periodic limb movements leading to arousal per hour (per hour of Total Sleep Time \[TST\]). Arithmetic mean of PLMAI of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  2. Subjective Total Sleep Time (sTST)

    sTST as derived from Subjective Sleep Questionnaire (SSQ), a participant reported subjective estimate of the total amount of time the participant was asleep after lights out until final awakening. Completed by the participant 30 minutes after waking; recall period is the night before. Arithmetic mean of sTST of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 3 and Week 5 of Each Intervention Period or ET

  3. Minutes of Stage N1, N2, N3 and R Sleep

    Minutes of Stage 1 Non-Rapid Eye Movement (Non-REM) sleep (Stage N1), Stage 2 Non-REM sleep (Stage N2), Stage 3 Non-REM sleep (Stage N3) or Slow Wave Sleep (SWS) and Stage REM (Stage R) sleep, as determined by PSG were calculated as total number of Stage N1 30-second (30-sec) epochs divided by 2, total number of Stage N2 30-sec epochs divided by 2, total number of Stage N3 30-sec epochs divided by 2 and total number of Stage R 30-sec epochs divided by 2 respectively. Arithmetic mean of minutes of stage N1, N2, N3 and R sleep of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  4. Number of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)

    NAASO1, as determined by PSG, was the number of times there was a wake period of at least 1 epoch from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage 2 Non-REM \[Stage N2\] 30-second (30-sec) epoch, Stage 3 Non-REM \[Stage N3\] 30-sec epoch, or stage rapid eye movement \[stage R\] 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period. Arithmetic mean of NAASO1 of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  5. Restless Legs Syndrome-Next Day Impact (RLS-NDI)

    RLS-NDI:participant-rated instrument to assess daytime performance and participant's previous night's sleep, consists of 14 items encompassing 5 domains:tiredness;emotional functioning;social functioning;cognitive functioning;activities of daily living and 1 global item for overall well-being. Each item: 0-10 scale; 0=Not at all; 10=Extremely. Total score: sum of scores from question 1-14 (question 10, 11: scores reversed). Total score range: 0-140; higher scores: more severe impact. Arithmetic mean of RLS-NDI of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 3 and Week 5 of Each Intervention Period or ET

  6. Periodic Limb Movement Index (PLMI)

    PLMI, as determined by PSG was number of periodic limb movements per hour based on time in bed (TIB). Arithmetic mean of PLMI of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  7. Periodic Limb Movement in Sleep Index (PLMSI)

    PLMSI, as determined by PSG was number of periodic limb movements in sleep per hour based on TST. Arithmetic mean of PLMSI of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  8. Number of Awakenings of at Least 2 Epochs After Sleep Onset (NAASO2)

    NAASO2, as determined by PSG, was the number of times there was a wake period of at least 2 30-sec epochs from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage N2 30-sec epoch, Stage N3 30-sec epoch, or Stage R 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period. Arithmetic mean of NAASO2 of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  9. Number of Arousals (NASO)

    NASO, as determined by PSG, was calculated as number of times there is a shift from a stage N2 to N3 or R 30-sec epoch to a stage N1 30-sec epoch from the onset of persistent sleep to light on. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period. Arithmetic mean of NASO of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  10. Arousal Index (NASOI)

    Arousal index, as determined by PSG, was NASO per hours of sleep from the onset of persistent sleep to light on. Arithmetic mean of NASOI of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  11. International Restless Legs Syndrome Study Group Rating Scale (IRLS)

    IRLS: psychometrically; clinically valid; clinician-administered instrument assesses severity of RLS. RLS symptom severity and impact on daily living comprise of 10 items giving 2 subscale scores and 1 global score. Subscale scores: symptom severity(6 items) and impact on daily living(3 items), item 3 loaded equally on both subscales. Global score calculated from 10 items. Score of all items range from 0-4, total score range:0-40. Lower scores: lower severity and better quality of life. Arithmetic mean of IRLS of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  12. Percentage of Participants With Response to Clinical Global Impression - Improvement (CGI-I) Scale

    CGI-I: 7-point clinician rated scale to assess improvement in disease condition as compared to the start of the study medication (baseline), ranging from 1 (very much improved) to 7 (very much worse). Improvement is defined as a score of 1 (very much improved) or 2 (much improved). Higher score = more affected.

    Time frame: Baseline, Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  13. Latency to Stage R Sleep (LREM)

    LREM, as determined by PSG, was number of non-wake epochs from the beginning of the recording to the first occurrence of Stage R sleep divided by 2. Arithmetic mean of LREM of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  14. Latency to Persistent Sleep (LPS)

    LPS, as determined by PSG, was number of epochs from the beginning of the recording ("lights-out") to the start of the first 20 consecutive non-wake epochs (10 minutes of persistent sleep) divided by 2. Arithmetic mean of LPS of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  15. Wake Time During Sleep (WTDS)

    WTDS, as determined by PSG, was the number of wake (30-sec) epochs after the onset of persistent sleep and prior to the final awakening or at the end of 8-hour recording. WTDS was the sum of 2 consecutive days of recordings divided by 2 at the end of each intervention period. Arithmetic mean of WTDS of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  16. Wake Time After Sleep (WTAS)

    WTAS, as determined by PSG, was the number of wake (30-sec) epochs after the final awakening until the end of the 8-hour recording. WTAS was the sum of 2 consecutive days of recordings divided by 2 at the end of each intervention period. Arithmetic mean of WTAS of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  17. Total Sleep Time (TST)

    TST, as determined by PSG, was the number of non-wake (30-sec) epochs from the beginning of recording to the end of the recording. TST was the sum of 2 consecutive days of recording divided by 2 at the end of each intervention period. Arithmetic mean of TST of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  18. Sleep Efficiency (SE)

    SE, as determined by PSG, was the TST divided by the time in bed (TIB)(both in minutes), multiplied by 100. Sum of 2 consecutive days of recording divided by 2 at the end of each intervention period. Arithmetic mean of SE of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  19. Hourly and Quarterly Assessment of Wake After Sleep Onset (WASO)

    WASO, as determined by PSG was time spent awake from sleep onset to final awakening. WASO = (sum of WTDS 30-sec epochs and WTAS 30-sec epochs)/2, measured on 2 consecutive days at end of each intervention period by each individual hour (8 hours total) and each individual quarter of night (eight hours in 2 hour increments). Arithmetic mean of WASO of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  20. Hourly and Quarterly Assessment of Number of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)

    NAASO1, as determined by PSG, was the number of times there was a wake period of at least 1 30-sec epoch from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage N2 30-sec epoch, Stage N3 30-sec epoch, or Stage R 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of NAASO1 of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  21. Hourly and Quarterly Assessment of Number of Awakenings of at Least 2 Epoch After Sleep Onset (NAASO2)

    NAASO2, as determined by PSG, was the number of times there was a wake period of at least 2 30-sec epochs from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage N2 30-sec epoch, Stage N3 30-sec epoch, or Stage R 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of NAASO2 of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  22. Hourly and Quarterly Assessment of Number of Arousals (NASO)

    NASO, as determined by PSG was the number of times there is a shift from a stage N2 to N3 or R 30-sec epoch to a stage N1 30-sec epoch from the onset of persistent sleep to light on. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of NASO for each participant at each period was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  23. Hourly and Quarterly Assessment of Periodic Limb Movement (PLM)

    PLM, as determined by PSG was number of periodic limb movements based on time in bed (TIB). Calculated at each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of PLM of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  24. Hourly and Quarterly Assessment of Sleep Efficiency (SE)

    SE, as determined by PSG, was the TST divided by the time in bed (TIB)(both in minutes), multiplied by 100. Sum of 2 consecutive days of recording divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean for SE of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  25. Subjective Sleep Questionnaire (SSQ): Number of Awakenings Subscale

    SSQ: participant-rated instrument to assess sleep behavior; measures sleep quantity, quality. Comprised of 5 items giving 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. This (1 item) subscale: numerical rating completed by participant 30 minutes after waking; recall period: night before. Range: 0 awakenings to 30 awakenings. Lower value indicates better quality of sleep. Arithmetic mean of this subscale score of each participant for all periods was taken prior to employing linear mixed model. Results of hours of sleep subscale reported as sTST.

    Time frame: Week 3 and Week 5 of Each Intervention Period or ET

  26. Subjective Sleep Questionnaire (SSQ): Total Wake Time After Sleep Onset Subscale

    SSQ: participant-rated instrument to assess sleep behavior; measures sleep quantity, quality. Comprised of 5 items yielding 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. This 1 item subscale (in minutes): numerical rating completed by participant 30 minutes after waking; recall period: night before. Range: 0-1440 minutes. Lower value: better sleep. Arithmetic mean of this subscale score of each participant for all periods was taken prior to employing linear mixed model. Results of hours of sleep subscale reported as sTST.

    Time frame: Week 3 and Week 5 of each intervention period or ET

  27. Subjective Sleep Questionnaire (SSQ): Quality of Sleep Subscale

    SSQ: participant-rated instrument to assess sleep behavior; measures sleep quantity, quality. Comprised of 5 items yielding 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. This 1 item subscale: numerical rating completed by participant 30 minutes after waking; recall period: night before, Range: 0 to 100, higher score: better quality of sleep. Arithmetic mean of this subscale score of each participant for all periods was taken prior to employing linear mixed model. Results of hours of sleep subscale reported as sTST.

    Time frame: Week 3 and Week 5 of each intervention period or ET

  28. Subjective Sleep Questionnaire (SSQ): Latency Subscale

    SSQ: participant-rated instrument assesses sleep behavior; measures sleep quantity, quality. Comprised of 5 items giving 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. Latency (time to fall asleep \[in minutes\]): numerical rating completed by participant 30 minutes after waking; recall period: night before. Range: 0 - 840 minutes, lower value: better sleep. Arithmetic mean of subscale score of each participant for all periods was taken prior to employing linear mixed model. Hours of sleep subscale results reported as sTST.

    Time frame: Week 3 and Week 5 of each intervention period or ET

  29. Medical Outcomes Study - Sleep Scale (MOS-SS)

    MOS-SS:Participant rated instrument, assesses sleep quantity, quality;with 12 items(7 subscale scores:sleep disturbance, snoring, awakening short of breath/with headache, sleep adequacy, somnolence, sleep quantity, optimal sleep;2 composite index scores:sleep problems Index I, II). Subscale scores total range:0-100(except sleep quantity\[range 0-24 hours\], optimal sleep\[range 0-1: 0= \<7 or \>8 hours;1=7/8 hours\]). Higher scores=poorer sleep outcomes(except sleep quantity, adequacy). Arithmetic mean of MOS-SS scores of each participant for all periods was taken before linear mixed model analysis.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

  30. Restless Leg Syndrome - Quality of Life Scale (RLS-QoL)

    RLS-QoL: psychometrically and clinically valid and reliable participant-rated instrument, assesses impact of RLS on participant quality of life. Specifically, it assessed effects of RLS on health status function (symptom severity, daily activity, social functioning, sleep, concentrating and decision making, travelling, sexual activity, and work) giving a summary score ranging from 0-100. Higher scores reflect better quality of life. Recall period: 1 week prior to assessment. Arithmetic mean of RLS-QoL score of each participant for all periods was taken prior to employing linear mixed model.

    Time frame: Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET

07

Results

Posted Oct 8, 2012

Participant flow

First Intervention Period
Participant flow — First Intervention Period
MilestonePlacebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mg
Started151314151513
Completed151014111112
Not completed030441
Withdrew: Adverse event010100
Withdrew: Protocol violation000020
Withdrew: Insufficient clinical response000010
Withdrew: Other000110
Withdrew: Withdrawal by subject010101
Withdrew: Lost to follow-up010100
Placebo Wash-out Period (7 Days)
Participant flow — Placebo Wash-out Period (7 Days)
MilestonePlacebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mg
Started151014111112
Completed151014111112
Not completed000000
Second Intervention Period
Participant flow — Second Intervention Period
MilestonePlacebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mg
Started151014111112
Completed1481491011
Not completed120211
Withdrew: Adverse event020110
Withdrew: Protocol violation100000
Withdrew: Other000101
Placebo Wash-out Period (7 Days)
Participant flow — Placebo Wash-out Period (7 Days)
MilestonePlacebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mg
Started1481491011
Completed1481491011
Not completed000000
Third Intervention Period
Participant flow — Third Intervention Period
MilestonePlacebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mg
Started1481491011
Completed1381381010
Not completed101101
Withdrew: Protocol violation100000
Withdrew: Other000001
Withdrew: Adverse event001000
Withdrew: Withdrawal by subject000100

Outcome measures

PrimaryWake After Sleep Onset (WASO)

WASO as determined by Polysomnography (PSG) was time spent awake from sleep onset to final awakening. WASO= Wake Time During Sleep \[WTDS\] epochs + Wake Time After Sleep \[WTAS\] epochs)/2. WTDS: number of wake epochs (30 seconds of PSG recording) after onset of persistent sleep and prior to final awakening or end of 8-hour recording/2 and WTAS: number of wake epochs after final awakening until end of the 8-hour recording/2. WASO was measured on 2 consecutive days within a period. Arithmetic mean of WASO of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or Early Termination (ET)
Reported as:
Least squares mean · minutes
Wake After Sleep Onset (WASO)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Wake After Sleep Onset (WASO)51.50 (43.20 to 59.79)78.42 (70.34 to 86.51)78.60 (70.29 to 86.90)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was step 1 in a step-down procedure (if p-value \< 0.05, then continue to next step) used to control the Type I error rate.) · Ls mean difference: -27.10 · 95% CI -35.78 to -18.42
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -26.93 · 95% CI -35.54 to -18.32
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.9684 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.17 · 95% CI -8.72 to 8.38
SecondaryPeriodic Limb Movement Arousal Index (PLMAI)

PLMAI, as determined by PSG was number of periodic limb movements leading to arousal per hour (per hour of Total Sleep Time \[TST\]). Arithmetic mean of PLMAI of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · movement/hour
Periodic Limb Movement Arousal Index (PLMAI)
movement/hourPregabalin 300 mgPramipexole 0.5 mgPlacebo
Periodic Limb Movement Arousal Index (PLMAI)3.93 (2.49 to 5.36)2.66 (1.27 to 4.06)7.61 (6.17 to 9.04)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was step 2 in a step-down procedure (if p-value \< 0.05, then continue to next step) used to control the Type I error rate.) · Ls mean difference: -3.68 · 95% CI -5.44 to -1.92
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.1541 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 1.26 · 95% CI -0.48 to 3.01
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -4.94 · 95% CI -6.68 to -3.21
SecondarySubjective Total Sleep Time (sTST)

sTST as derived from Subjective Sleep Questionnaire (SSQ), a participant reported subjective estimate of the total amount of time the participant was asleep after lights out until final awakening. Completed by the participant 30 minutes after waking; recall period is the night before. Arithmetic mean of sTST of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 3 and Week 5 of Each Intervention Period or ET
Reported as:
Least squares mean · minutes
Subjective Total Sleep Time (sTST)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Subjective Total Sleep Time (sTST)400.97 (386.36 to 415.58)374.19 (360.00 to 388.37)370.16 (355.69 to 384.63)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was step 3 in a step-down procedure (if p-value \< 0.05, then continue to next step) used to control the Type I error rate.) · Ls mean difference: 30.81 · 95% CI 16.14 to 45.49
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0004 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 26.79 · 95% CI 12.26 to 41.32
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.5807 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 4.03 · 95% CI -10.36 to 18.41
SecondaryMinutes of Stage N1, N2, N3 and R Sleep

Minutes of Stage 1 Non-Rapid Eye Movement (Non-REM) sleep (Stage N1), Stage 2 Non-REM sleep (Stage N2), Stage 3 Non-REM sleep (Stage N3) or Slow Wave Sleep (SWS) and Stage REM (Stage R) sleep, as determined by PSG were calculated as total number of Stage N1 30-second (30-sec) epochs divided by 2, total number of Stage N2 30-sec epochs divided by 2, total number of Stage N3 30-sec epochs divided by 2 and total number of Stage R 30-sec epochs divided by 2 respectively. Arithmetic mean of minutes of stage N1, N2, N3 and R sleep of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Minutes of Stage N1, N2, N3 and R Sleep
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Stage N1 Sleep38.06 (32.97 to 43.14)48.38 (43.38 to 53.38)43.72 (38.63 to 48.81)
Stage N2 Sleep227.05 (215.01 to 239.09)241.52 (229.76 to 253.27)204.35 (192.29 to 216.40)
Stage N3 Sleep/SWS66.88 (57.78 to 75.98)34.78 (25.87 to 43.69)45.95 (36.85 to 55.06)
Stage R Sleep70.40 (64.32 to 76.48)51.80 (45.86 to 57.75)75.37 (69.29 to 81.45)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0076 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -5.67 · 95% CI -9.80 to -1.54
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -10.32 · 95% CI -14.43 to -6.21
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0257 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 4.65 · 95% CI 0.58 to 8.73
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0003 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 22.70 · 95% CI 10.74 to 34.67
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0174 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -14.47 · 95% CI -26.35 to -2.59
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 37.17 · 95% CI 25.38 to 48.96
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 20.93 · 95% CI 12.61 to 29.25
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was step 4 in a step-down procedure (if p-value \< 0.05, then continue to next step) used to control the Type I error rate.) · Ls mean difference: 32.10 · 95% CI 23.83 to 40.36
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0080 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -11.17 · 95% CI -19.37 to -2.97
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0834 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -4.97 · 95% CI -10.61 to 0.67
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 18.59 · 95% CI 12.99 to 24.19
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -23.56 · 95% CI -29.12 to -18.01
SecondaryNumber of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)

NAASO1, as determined by PSG, was the number of times there was a wake period of at least 1 epoch from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage 2 Non-REM \[Stage N2\] 30-second (30-sec) epoch, Stage 3 Non-REM \[Stage N3\] 30-sec epoch, or stage rapid eye movement \[stage R\] 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period. Arithmetic mean of NAASO1 of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · awakenings
Number of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)
awakeningsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Number of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)18.43 (16.49 to 20.36)26.30 (24.41 to 28.19)21.10 (19.16 to 23.04)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0077 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.67 · 95% CI -4.63 to -0.72
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was step 5 in a step-down procedure (if p-value \< 0.05, then continue to next step) used to control the Type I error rate.) · Ls mean difference: -7.87 · 95% CI -9.81 to -5.93
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 5.20 · 95% CI 3.27 to 7.12
SecondaryRestless Legs Syndrome-Next Day Impact (RLS-NDI)

RLS-NDI:participant-rated instrument to assess daytime performance and participant's previous night's sleep, consists of 14 items encompassing 5 domains:tiredness;emotional functioning;social functioning;cognitive functioning;activities of daily living and 1 global item for overall well-being. Each item: 0-10 scale; 0=Not at all; 10=Extremely. Total score: sum of scores from question 1-14 (question 10, 11: scores reversed). Total score range: 0-140; higher scores: more severe impact. Arithmetic mean of RLS-NDI of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 3 and Week 5 of Each Intervention Period or ET
Reported as:
Least squares mean · units on a scale
Restless Legs Syndrome-Next Day Impact (RLS-NDI)
units on a scalePregabalin 300 mgPramipexole 0.5 mgPlacebo
Restless Legs Syndrome-Next Day Impact (RLS-NDI)41.43 (35.36 to 47.50)46.33 (40.39 to 52.27)46.78 (40.75 to 52.81)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0396 (This analysis was step 6 in a step-down procedure (if p-value \< 0.05, then continue to next step) used to control the Type I error rate.) · Ls mean difference: -5.35 · 95% CI -10.44 to -0.26
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0568 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -4.90 · 95% CI -9.95 to 0.14
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.8589 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.45 · 95% CI -5.44 to 4.54
SecondaryPeriodic Limb Movement Index (PLMI)

PLMI, as determined by PSG was number of periodic limb movements per hour based on time in bed (TIB). Arithmetic mean of PLMI of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · movement/hour
Periodic Limb Movement Index (PLMI)
movement/hourPregabalin 300 mgPramipexole 0.5 mgPlacebo
Periodic Limb Movement Index (PLMI)25.45 (20.99 to 29.91)14.11 (9.79 to 18.42)39.95 (35.48 to 44.41)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -14.50 · 95% CI -20.26 to -8.74
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 11.35 · 95% CI 5.65 to 17.04
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -25.84 · 95% CI -31.51 to -20.17
SecondaryPeriodic Limb Movement in Sleep Index (PLMSI)

PLMSI, as determined by PSG was number of periodic limb movements in sleep per hour based on TST. Arithmetic mean of PLMSI of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · movement/hour
Periodic Limb Movement in Sleep Index (PLMSI)
movement/hourPregabalin 300 mgPramipexole 0.5 mgPlacebo
Periodic Limb Movement in Sleep Index (PLMSI)22.42 (17.46 to 27.39)8.00 (3.20 to 12.80)36.95 (31.99 to 41.92)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -14.53 · 95% CI -20.84 to -8.22
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 14.42 · 95% CI 8.18 to 20.67
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -28.95 · 95% CI -35.16 to -22.74
SecondaryNumber of Awakenings of at Least 2 Epochs After Sleep Onset (NAASO2)

NAASO2, as determined by PSG, was the number of times there was a wake period of at least 2 30-sec epochs from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage N2 30-sec epoch, Stage N3 30-sec epoch, or Stage R 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period. Arithmetic mean of NAASO2 of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · awakenings
Number of Awakenings of at Least 2 Epochs After Sleep Onset (NAASO2)
awakeningsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Number of Awakenings of at Least 2 Epochs After Sleep Onset (NAASO2)7.68 (6.55 to 8.82)12.39 (11.28 to 13.50)10.55 (9.42 to 11.68)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.86 · 95% CI -3.93 to -1.80
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -4.71 · 95% CI -5.76 to -3.65
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0007 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 1.84 · 95% CI 0.79 to 2.89
SecondaryNumber of Arousals (NASO)

NASO, as determined by PSG, was calculated as number of times there is a shift from a stage N2 to N3 or R 30-sec epoch to a stage N1 30-sec epoch from the onset of persistent sleep to light on. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period. Arithmetic mean of NASO of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · arousals
Number of Arousals (NASO)
arousalsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Number of Arousals (NASO)17.84 (15.06 to 20.61)24.19 (21.47 to 26.90)20.29 (17.51 to 23.06)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0617 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.45 · 95% CI -5.02 to 0.12
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -6.35 · 95% CI -8.91 to -3.80
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0028 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 3.90 · 95% CI 1.37 to 6.44
SecondaryArousal Index (NASOI)

Arousal index, as determined by PSG, was NASO per hours of sleep from the onset of persistent sleep to light on. Arithmetic mean of NASOI of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · arousals/hour
Arousal Index (NASOI)
arousals/hourPregabalin 300 mgPramipexole 0.5 mgPlacebo
Arousal Index (NASOI)2.75 (2.23 to 3.28)4.18 (3.67 to 4.69)3.44 (2.92 to 3.96)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0056 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.69 · 95% CI -1.17 to -0.21
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -1.42 · 95% CI -1.90 to -0.95
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0026 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.74 · 95% CI 0.26 to 1.21
SecondaryInternational Restless Legs Syndrome Study Group Rating Scale (IRLS)

IRLS: psychometrically; clinically valid; clinician-administered instrument assesses severity of RLS. RLS symptom severity and impact on daily living comprise of 10 items giving 2 subscale scores and 1 global score. Subscale scores: symptom severity(6 items) and impact on daily living(3 items), item 3 loaded equally on both subscales. Global score calculated from 10 items. Score of all items range from 0-4, total score range:0-40. Lower scores: lower severity and better quality of life. Arithmetic mean of IRLS of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · units on a scale
International Restless Legs Syndrome Study Group Rating Scale (IRLS)
units on a scalePregabalin 300 mgPramipexole 0.5 mgPlacebo
International Restless Legs Syndrome Study Group Rating Scale (IRLS)12.28 (10.32 to 14.24)15.35 (13.42 to 17.28)18.38 (16.42 to 20.34)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -6.10 · 95% CI -8.10 to -4.09
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0029 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -3.07 · 95% CI -5.07 to -1.07
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0032 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -3.03 · 95% CI -5.02 to -1.04
SecondaryPercentage of Participants With Response to Clinical Global Impression - Improvement (CGI-I) Scale

CGI-I: 7-point clinician rated scale to assess improvement in disease condition as compared to the start of the study medication (baseline), ranging from 1 (very much improved) to 7 (very much worse). Improvement is defined as a score of 1 (very much improved) or 2 (much improved). Higher score = more affected.

Time frame:
Baseline, Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Number · percentage of participants
Percentage of Participants With Response to Clinical Global Impression - Improvement (CGI-I) Scale
percentage of participantsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Percentage of Participants With Response to Clinical Global Impression - Improvement (CGI-I) Scale61.250.033.3
SecondaryLatency to Stage R Sleep (LREM)

LREM, as determined by PSG, was number of non-wake epochs from the beginning of the recording to the first occurrence of Stage R sleep divided by 2. Arithmetic mean of LREM of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Latency to Stage R Sleep (LREM)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Latency to Stage R Sleep (LREM)95.22 (82.11 to 108.33)130.99 (118.26 to 143.72)84.52 (71.40 to 97.64)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.1677 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 10.69 · 95% CI -4.56 to 25.95
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -35.77 · 95% CI -50.88 to -20.66
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 46.47 · 95% CI 31.45 to 61.48
SecondaryLatency to Persistent Sleep (LPS)

LPS, as determined by PSG, was number of epochs from the beginning of the recording ("lights-out") to the start of the first 20 consecutive non-wake epochs (10 minutes of persistent sleep) divided by 2. Arithmetic mean of LPS of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Latency to Persistent Sleep (LPS)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Latency to Persistent Sleep (LPS)31.13 (22.06 to 40.19)31.52 (22.68 to 40.36)38.86 (29.78 to 47.93)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.1040 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -7.73 · 95% CI -17.07 to 1.61
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.9325 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.40 · 95% CI -9.67 to 8.87
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.1175 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -7.33 · 95% CI -16.54 to 1.87
SecondaryWake Time During Sleep (WTDS)

WTDS, as determined by PSG, was the number of wake (30-sec) epochs after the onset of persistent sleep and prior to the final awakening or at the end of 8-hour recording. WTDS was the sum of 2 consecutive days of recordings divided by 2 at the end of each intervention period. Arithmetic mean of WTDS of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Wake Time During Sleep (WTDS)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Wake Time During Sleep (WTDS)45.77 (37.81 to 53.73)70.51 (62.77 to 78.25)69.75 (61.78 to 77.72)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -23.98 · 95% CI -32.78 to -15.18
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -24.74 · 95% CI -33.46 to -16.02
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.8622 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.76 · 95% CI -7.90 to 9.43
SecondaryWake Time After Sleep (WTAS)

WTAS, as determined by PSG, was the number of wake (30-sec) epochs after the final awakening until the end of the 8-hour recording. WTAS was the sum of 2 consecutive days of recordings divided by 2 at the end of each intervention period. Arithmetic mean of WTAS of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Wake Time After Sleep (WTAS)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Wake Time After Sleep (WTAS)5.58 (2.15 to 9.00)7.86 (4.53 to 11.19)8.88 (5.45 to 12.30)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0800 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -3.30 · 95% CI -7.00 to 0.40
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.2209 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.28 · 95% CI -5.95 to 1.39
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.5815 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -1.02 · 95% CI -4.66 to 2.63
SecondaryTotal Sleep Time (TST)

TST, as determined by PSG, was the number of non-wake (30-sec) epochs from the beginning of recording to the end of the recording. TST was the sum of 2 consecutive days of recording divided by 2 at the end of each intervention period. Arithmetic mean of TST of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Total Sleep Time (TST)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Total Sleep Time (TST)402.38 (390.60 to 414.15)376.52 (364.99 to 388.05)369.66 (357.88 to 381.44)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 32.72 · 95% CI 22.02 to 43.42
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 25.86 · 95% CI 15.22 to 36.49
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.2005 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 6.86 · 95% CI -3.69 to 17.42
SecondarySleep Efficiency (SE)

SE, as determined by PSG, was the TST divided by the time in bed (TIB)(both in minutes), multiplied by 100. Sum of 2 consecutive days of recording divided by 2 at the end of each intervention period. Arithmetic mean of SE of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · Percentage of time asleep
Sleep Efficiency (SE)
Percentage of time asleepPregabalin 300 mgPramipexole 0.5 mgPlacebo
Sleep Efficiency (SE)83.81 (81.36 to 86.27)78.58 (76.17 to 80.98)77.02 (74.56 to 79.48)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 6.80 · 95% CI 4.57 to 9.02
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 5.24 · 95% CI 3.02 to 7.45
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.1622 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 1.56 · 95% CI -0.64 to 3.75
SecondaryHourly and Quarterly Assessment of Wake After Sleep Onset (WASO)

WASO, as determined by PSG was time spent awake from sleep onset to final awakening. WASO = (sum of WTDS 30-sec epochs and WTAS 30-sec epochs)/2, measured on 2 consecutive days at end of each intervention period by each individual hour (8 hours total) and each individual quarter of night (eight hours in 2 hour increments). Arithmetic mean of WASO of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · minutes
Hourly and Quarterly Assessment of Wake After Sleep Onset (WASO)
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Hour 1 (n= 66, 67, 66)1.62 ± 4.122.26 ± 2.693.35 ± 3.84
Hour 2 (n= 67, 70, 66)5.04 ± 6.157.07 ± 5.487.39 ± 6.85
Hour 3 (n= 67, 70, 67)4.89 (3.14 to 6.64)8.23 (6.52 to 9.93)8.90 (7.13 to 10.68)
Hour 4 (n= 67, 70, 68)6.21 (4.29 to 8.13)11.54 (9.67 to 13.42)9.52 (7.59 to 11.44)
Hour 5 (n= 67, 70, 68)5.93 (3.80 to 8.06)10.39 (8.32 to 12.46)10.04 (7.91 to 12.17)
Hour 6 (n= 67, 71, 68)5.78 (3.49 to 8.08)10.54 (8.32 to 12.76)10.52 (8.22 to 12.81)
Hour 7 (n= 67, 71, 68)9.18 (6.72 to 11.64)11.44 (9.06 to 13.82)12.09 (9.63 to 14.55)
Hour 8 (n= 67, 71, 68)13.16 (10.09 to 16.23)18.27 (15.28 to 21.25)18.15 (15.08 to 21.22)
Quarter 1 (n= 67, 70, 66)6.42 (4.59 to 8.26)8.99 (7.20 to 10.78)10.35 (8.47 to 12.23)
Quarter 2 (n= 67, 70, 68)11.08 (8.09 to 14.07)19.77 (16.86 to 22.69)18.18 (15.19 to 21.17)
Quarter 3 (n= 67, 71, 68)11.81 (8.03 to 15.59)20.77 (17.11 to 24.42)20.55 (16.77 to 24.33)
Quarter 4 (n= 67, 71, 68)22.37 (17.70 to 27.04)29.55 (25.00 to 34.10)30.21 (25.54 to 34.89)
SecondaryHourly and Quarterly Assessment of Number of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)

NAASO1, as determined by PSG, was the number of times there was a wake period of at least 1 30-sec epoch from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage N2 30-sec epoch, Stage N3 30-sec epoch, or Stage R 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of NAASO1 of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · awakenings
Hourly and Quarterly Assessment of Number of Awakenings of at Least 1 Epoch After Sleep Onset (NAASO1)
awakeningsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Hour 1 (n= 66, 67, 66)0.70 ± 0.901.39 ± 1.121.10 ± 0.76
Hour 2 (n= 67, 70, 66)2.06 ± 1.413.32 ± 1.742.47 ± 1.44
Hour 3 (n= 67, 70, 67)2.09 (1.69 to 2.48)3.42 (3.03 to 3.81)2.66 (2.25 to 3.06)
Hour 4 (n= 67, 70, 68)2.44 (2.00 to 2.88)3.83 (3.40 to 4.25)2.71 (2.27 to 3.15)
Hour 5 (n= 67, 70, 68)2.47 (2.06 to 2.89)3.76 (3.36 to 4.17)2.87 (2.46 to 3.29)
Hour 6 (n= 67, 71, 68)2.91 (2.46 to 3.36)3.68 (3.24 to 4.12)3.16 (2.71 to 3.62)
Hour 7 (n= 67, 71, 68)3.07 (2.62 to 3.53)4.04 (3.60 to 4.47)3.32 (2.87 to 3.77)
Hour 8 (n= 67, 71, 68)2.76 (2.30 to 3.21)3.46 (3.02 to 3.90)3.11 (2.65 to 3.56)
Quarter 1 (n= 67, 70, 66)2.71 (2.22 to 3.20)4.61 (4.13 to 5.09)3.49 (2.98 to 3.99)
Quarter 2 (n= 67, 70, 68)4.53 (3.86 to 5.21)7.27 (6.61 to 7.93)5.32 (4.64 to 5.99)
Quarter 3 (n= 67, 71, 68)5.39 (4.66 to 6.12)7.37 (6.66 to 8.08)6.04 (5.31 to 6.77)
Quarter 4 (n= 67, 71, 68)5.87 (5.15 to 6.59)7.36 (6.67 to 8.06)6.44 (5.73 to 7.16)
SecondaryHourly and Quarterly Assessment of Number of Awakenings of at Least 2 Epoch After Sleep Onset (NAASO2)

NAASO2, as determined by PSG, was the number of times there was a wake period of at least 2 30-sec epochs from the onset of persistent sleep to light on. Each entry to be counted must be separated by a Stage N2 30-sec epoch, Stage N3 30-sec epoch, or Stage R 30-sec epoch. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of NAASO2 of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · awakenings
Hourly and Quarterly Assessment of Number of Awakenings of at Least 2 Epoch After Sleep Onset (NAASO2)
awakeningsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Hour 1 (n= 66, 67, 66)0.42 ± 0.600.61 ± 0.710.73 ± 0.59
Hour 2 (n= 67, 70, 66)1.04 ± 0.831.72 ± 1.131.37 ± 1.06
Hour 3 (n= 67, 70, 67)0.99 (0.75 to 1.23)1.71 (1.48 to 1.95)1.41 (1.17 to 1.65)
Hour 4 (n= 67, 70, 68)1.01 (0.74 to 1.27)1.84 (1.58 to 2.09)1.48 (1.22 to 1.74)
Hour 5 (n= 67, 70, 68)1.06 (0.81 to 1.31)1.76 (1.52 to 2.01)1.48 (1.22 to 1.73)
Hour 6 (n= 67, 71, 68)1.02 (0.79 to 1.26)1.57 (1.34 to 1.80)1.44 (1.20 to 1.68)
Hour 7 (n= 67, 71, 68)1.24 (0.97 to 1.51)1.94 (1.68 to 2.20)1.57 (1.30 to 1.84)
Hour 8 (n= 67, 71, 68)1.00 (0.75 to 1.24)1.56 (1.32 to 1.79)1.28 (1.04 to 1.52)
Quarter 1 (n= 67, 70, 66)1.43 (1.11 to 1.75)2.27 (1.96 to 2.58)2.06 (1.73 to 2.38)
Quarter 2 (n= 67, 70, 68)1.99 (1.58 to 2.39)3.56 (3.16 to 3.96)2.85 (2.44 to 3.26)
Quarter 3 (n= 67, 71, 68)2.10 (1.68 to 2.51)3.30 (2.89 to 3.70)2.92 (2.50 to 3.34)
Quarter 4 (n= 67, 71, 68)2.25 (1.86 to 2.64)3.44 (3.06 to 3.82)2.86 (2.47 to 3.25)
SecondaryHourly and Quarterly Assessment of Number of Arousals (NASO)

NASO, as determined by PSG was the number of times there is a shift from a stage N2 to N3 or R 30-sec epoch to a stage N1 30-sec epoch from the onset of persistent sleep to light on. The sum of 2 consecutive days of recording was divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of NASO for each participant at each period was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · arousals
Hourly and Quarterly Assessment of Number of Arousals (NASO)
arousalsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Hour 1 (n= 66, 67, 66)1.48 ± 1.652.06 ± 2.221.79 ± 1.78
Hour 2 (n= 67, 70, 66)2.36 ± 2.033.23 ± 2.152.68 ± 1.99
Hour 3 (n= 67, 70, 67)2.31 (1.75 to 2.87)3.23 (2.68 to 3.78)2.80 (2.23 to 3.37)
Hour 4 (n= 67, 70, 68)2.94 (2.39 to 3.49)3.41 (2.88 to 3.94)2.76 (2.22 to 3.31)
Hour 5 (n= 67, 70, 68)2.33 (1.76 to 2.90)3.20 (2.64 to 3.75)2.89 (2.32 to 3.46)
Hour 6 (n= 67, 71, 68)2.39 (1.88 to 2.90)3.30 (2.80 to 3.80)2.70 (2.19 to 3.22)
Hour 7 (n= 67, 71, 68)2.15 (1.67 to 2.63)3.28 (2.81 to 3.75)2.66 (2.18 to 3.14)
Hour 8 (n= 67, 71, 68)2.07 (1.56 to 2.57)2.98 (2.49 to 3.46)2.46 (1.96 to 2.97)
Quarter 1 (n= 67, 70, 66)3.75 (2.93 to 4.57)5.09 (4.28 to 5.89)4.26 (3.43 to 5.09)
Quarter 2 (n= 67, 70, 68)5.25 (4.32 to 6.18)6.67 (5.76 to 7.57)5.55 (4.62 to 6.48)
Quarter 3 (n= 67, 71, 68)4.75 (3.86 to 5.64)6.44 (5.58 to 7.30)5.61 (4.72 to 6.50)
Quarter 4 (n= 67, 71, 68)4.23 (3.39 to 5.06)6.24 (5.43 to 7.04)5.13 (4.29 to 5.96)
SecondaryHourly and Quarterly Assessment of Periodic Limb Movement (PLM)

PLM, as determined by PSG was number of periodic limb movements based on time in bed (TIB). Calculated at each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean of PLM of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · movement/hour
Hourly and Quarterly Assessment of Periodic Limb Movement (PLM)
movement/hourPregabalin 300 mgPramipexole 0.5 mgPlacebo
Hour 131.45 ± 29.7021.57 ± 27.0354.67 ± 39.98
Hour 226.38 ± 29.2012.49 ± 14.5152.93 ± 40.92
Hour 340.93 (32.38 to 49.48)14.05 (5.77 to 22.32)48.76 (40.20 to 57.32)
Hour 430.35 (23.05 to 37.64)14.50 (7.45 to 21.55)46.58 (39.29 to 53.88)
Hour 525.70 (19.02 to 32.38)11.93 (5.47 to 18.38)36.17 (29.49 to 42.86)
Hour 621.02 (15.01 to 27.04)10.57 (4.75 to 16.38)32.47 (26.45 to 38.49)
Hour 714.22 (9.06 to 19.37)11.11 (6.12 to 16.09)27.04 (21.88 to 32.20)
Hour 813.37 (8.54 to 18.20)16.55 (11.86 to 21.24)20.97 (16.14 to 25.81)
Quarter 157.82 (44.51 to 71.12)34.02 (21.14 to 46.91)107.56 (94.24 to 120.87)
Quarter 271.29 (56.94 to 85.64)28.55 (14.66 to 42.43)95.31 (80.95 to 109.67)
Quarter 346.77 (35.42 to 58.11)22.49 (11.51 to 33.46)68.66 (57.30 to 80.01)
Quarter 427.60 (18.97 to 36.24)27.64 (19.28 to 36.00)48.01 (39.36 to 56.65)
SecondaryHourly and Quarterly Assessment of Sleep Efficiency (SE)

SE, as determined by PSG, was the TST divided by the time in bed (TIB)(both in minutes), multiplied by 100. Sum of 2 consecutive days of recording divided by 2 at the end of each intervention period by each individual hour (8 hours total) and each individual quarter of the night (eight hours in 2 hour increments). Arithmetic mean for SE of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · percentage of time asleep
Hourly and Quarterly Assessment of Sleep Efficiency (SE)
percentage of time asleepPregabalin 300 mgPramipexole 0.5 mgPlacebo
Hour 162.31 ± 24.1466.88 ± 24.3057.80 ± 22.90
Hour 286.13 ± 16.9483.43 ± 16.0377.31 ± 20.49
Hour 390.22 (86.68 to 93.77)84.86 (81.43 to 88.29)81.86 (78.32 to 85.40)
Hour 489.41 (85.86 to 92.97)79.84 (76.40 to 83.28)82.61 (79.05 to 86.16)
Hour 590.00 (86.30 to 93.70)81.85 (78.27 to 85.43)82.92 (79.22 to 86.63)
Hour 690.33 (86.45 to 94.21)81.64 (77.88 to 85.39)82.49 (78.61 to 86.38)
Hour 784.70 (80.60 to 88.80)80.90 (76.92 to 84.87)79.86 (75.76 to 83.96)
Hour 878.07 (72.95 to 83.19)69.51 (64.53 to 74.50)69.75 (64.63 to 74.88)
Quarter 174.21 (69.69 to 78.73)75.15 (70.73 to 79.57)67.62 (63.10 to 72.15)
Quarter 289.84 (86.77 to 92.92)82.37 (79.38 to 85.35)82.30 (79.23 to 85.38)
Quarter 390.09 (86.83 to 93.34)81.74 (78.59 to 84.90)82.75 (79.49 to 86.01)
Quarter 481.37 (77.45 to 85.28)75.16 (71.35 to 78.97)74.84 (70.93 to 78.76)
SecondarySubjective Sleep Questionnaire (SSQ): Number of Awakenings Subscale

SSQ: participant-rated instrument to assess sleep behavior; measures sleep quantity, quality. Comprised of 5 items giving 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. This (1 item) subscale: numerical rating completed by participant 30 minutes after waking; recall period: night before. Range: 0 awakenings to 30 awakenings. Lower value indicates better quality of sleep. Arithmetic mean of this subscale score of each participant for all periods was taken prior to employing linear mixed model. Results of hours of sleep subscale reported as sTST.

Time frame:
Week 3 and Week 5 of Each Intervention Period or ET
Reported as:
Least squares mean · awakenings
Subjective Sleep Questionnaire (SSQ): Number of Awakenings Subscale
awakeningsPregabalin 300 mgPramipexole 0.5 mgPlacebo
Subjective Sleep Questionnaire (SSQ): Number of Awakenings Subscale1.69 (1.34 to 2.03)2.64 (2.31 to 2.98)2.51 (2.17 to 2.86)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.83 · 95% CI -1.18 to -0.47
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.96 · 95% CI -1.31 to -0.60
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.4677 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.13 · 95% CI -0.22 to 0.48
SecondarySubjective Sleep Questionnaire (SSQ): Total Wake Time After Sleep Onset Subscale

SSQ: participant-rated instrument to assess sleep behavior; measures sleep quantity, quality. Comprised of 5 items yielding 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. This 1 item subscale (in minutes): numerical rating completed by participant 30 minutes after waking; recall period: night before. Range: 0-1440 minutes. Lower value: better sleep. Arithmetic mean of this subscale score of each participant for all periods was taken prior to employing linear mixed model. Results of hours of sleep subscale reported as sTST.

Time frame:
Week 3 and Week 5 of each intervention period or ET
Reported as:
Least squares mean · minutes
Subjective Sleep Questionnaire (SSQ): Total Wake Time After Sleep Onset Subscale
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Subjective Sleep Questionnaire (SSQ): Total Wake Time After Sleep Onset Subscale53.78 (42.94 to 64.61)82.23 (71.76 to 92.70)79.09 (68.46 to 89.72)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -25.32 · 95% CI -35.83 to -14.80
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -28.45 · 95% CI -38.89 to -18.02
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.5461 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 3.14 · 95% CI -7.13 to 13.40
SecondarySubjective Sleep Questionnaire (SSQ): Quality of Sleep Subscale

SSQ: participant-rated instrument to assess sleep behavior; measures sleep quantity, quality. Comprised of 5 items yielding 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. This 1 item subscale: numerical rating completed by participant 30 minutes after waking; recall period: night before, Range: 0 to 100, higher score: better quality of sleep. Arithmetic mean of this subscale score of each participant for all periods was taken prior to employing linear mixed model. Results of hours of sleep subscale reported as sTST.

Time frame:
Week 3 and Week 5 of each intervention period or ET
Reported as:
Least squares mean · units on a scale
Subjective Sleep Questionnaire (SSQ): Quality of Sleep Subscale
units on a scalePregabalin 300 mgPramipexole 0.5 mgPlacebo
Subjective Sleep Questionnaire (SSQ): Quality of Sleep Subscale6.74 (6.35 to 7.13)5.69 (5.31 to 6.06)5.70 (5.32 to 6.08)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 1.04 · 95% CI 0.63 to 1.45
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 1.05 · 95% CI 0.65 to 1.46
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.9403 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.02 · 95% CI -0.42 to 0.39
SecondarySubjective Sleep Questionnaire (SSQ): Latency Subscale

SSQ: participant-rated instrument assesses sleep behavior; measures sleep quantity, quality. Comprised of 5 items giving 5 subscale scores: latency, hours of sleep, number of awakenings, total wake time after sleep onset, quality of sleep. Latency (time to fall asleep \[in minutes\]): numerical rating completed by participant 30 minutes after waking; recall period: night before. Range: 0 - 840 minutes, lower value: better sleep. Arithmetic mean of subscale score of each participant for all periods was taken prior to employing linear mixed model. Hours of sleep subscale results reported as sTST.

Time frame:
Week 3 and Week 5 of each intervention period or ET
Reported as:
Least squares mean · minutes
Subjective Sleep Questionnaire (SSQ): Latency Subscale
minutesPregabalin 300 mgPramipexole 0.5 mgPlacebo
Subjective Sleep Questionnaire (SSQ): Latency Subscale42.49 (34.26 to 50.72)40.59 (32.52 to 48.66)50.07 (41.89 to 58.25)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0215 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -7.58 · 95% CI -14.03 to -1.14
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.5569 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 1.90 · 95% CI -4.49 to 8.29
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0036 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -9.48 · 95% CI -15.81 to -3.16
SecondaryMedical Outcomes Study - Sleep Scale (MOS-SS)

MOS-SS:Participant rated instrument, assesses sleep quantity, quality;with 12 items(7 subscale scores:sleep disturbance, snoring, awakening short of breath/with headache, sleep adequacy, somnolence, sleep quantity, optimal sleep;2 composite index scores:sleep problems Index I, II). Subscale scores total range:0-100(except sleep quantity\[range 0-24 hours\], optimal sleep\[range 0-1: 0= \<7 or \>8 hours;1=7/8 hours\]). Higher scores=poorer sleep outcomes(except sleep quantity, adequacy). Arithmetic mean of MOS-SS scores of each participant for all periods was taken before linear mixed model analysis.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · units on a scale
Medical Outcomes Study - Sleep Scale (MOS-SS)
units on a scalePregabalin 300 mgPramipexole 0.5 mgPlacebo
Awaken Short of Breath/with Headache (n= 68,71,69)11.59 (6.20 to 16.97)13.10 (7.77 to 18.44)10.88 (5.49 to 16.27)
Adequacy (n= 68,71,69)54.96 (48.11 to 61.81)43.90 (37.21 to 50.58)40.79 (33.93 to 47.65)
Somnolence (n= 68,71,69)21.28 (17.08 to 25.47)21.32 (17.21 to 25.44)23.71 (19.51 to 27.90)
Sleep Quantity (n= 68,71,69)6.43 (5.95 to 6.91)6.50 (6.03 to 6.97)5.97 (5.49 to 6.46)
6-Item Sleep Problems Index (n= 68,71,69)30.69 (25.94 to 35.45)37.24 (32.58 to 41.89)40.59 (35.83 to 45.34)
9-Item Sleep Problems Index (n= 68,71,69)32.75 (28.06 to 37.44)37.88 (33.28 to 42.47)42.89 (38.20 to 47.59)
Optimal Sleep (n= 68,71,69)0.43 (0.32 to 0.54)0.35 (0.24 to 0.46)0.29 (0.18 to 0.40)
Sleep Disturbance (n= 68,71,69)34.08 (28.11 to 40.06)40.19 (34.34 to 46.04)48.65 (42.66 to 54.63)
Snoring (n= 67,71,68)15.27 (10.05 to 20.49)15.97 (10.86 to 21.08)17.96 (12.75 to 23.17)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.6947 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.71 · 95% CI -2.85 to 4.27
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.3980 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -1.52 · 95% CI -5.06 to 2.02
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.2144 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 2.23 · 95% CI -1.30 to 5.76
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0006 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 14.17 · 95% CI 6.25 to 22.08
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0061 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 11.07 · 95% CI 3.22 to 18.92
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.4342 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 3.10 · 95% CI -4.72 to 10.93
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.2420 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.43 · 95% CI -6.53 to 1.66
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.9810 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.05 · 95% CI -4.12 to 4.02
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.2468 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.38 · 95% CI -6.44 to 1.67
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.1496 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.46 · 95% CI -0.17 to 1.09
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.8184 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.07 · 95% CI -0.69 to 0.55
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0918 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.53 · 95% CI -0.09 to 1.15
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -9.89 · 95% CI -14.80 to -4.99
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0089 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -6.54 · 95% CI -11.42 to -1.67
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.1746 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -3.35 · 95% CI -8.21 to 1.51
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -10.14 · 95% CI -14.96 to -5.32
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0359 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -5.13 · 95% CI -9.91 to -0.34
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0395 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -5.01 · 95% CI -9.78 to -0.24
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0278 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.14 · 95% CI 0.02 to 0.27
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.2000 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.08 · 95% CI -0.04 to 0.20
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.3396 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 0.06 · 95% CI -0.06 to 0.18
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = <0.0001 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -14.56 · 95% CI -20.93 to -8.19
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0584 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -6.11 · 95% CI -12.43 to 0.22
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.0090 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -8.45 · 95% CI -14.76 to -2.15
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.2405 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -2.69 · 95% CI -7.20 to 1.82
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.7565 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -0.70 · 95% CI -5.18 to 3.77
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.3792 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: -1.98 · 95% CI -6.43 to 2.47
SecondaryRestless Leg Syndrome - Quality of Life Scale (RLS-QoL)

RLS-QoL: psychometrically and clinically valid and reliable participant-rated instrument, assesses impact of RLS on participant quality of life. Specifically, it assessed effects of RLS on health status function (symptom severity, daily activity, social functioning, sleep, concentrating and decision making, travelling, sexual activity, and work) giving a summary score ranging from 0-100. Higher scores reflect better quality of life. Recall period: 1 week prior to assessment. Arithmetic mean of RLS-QoL score of each participant for all periods was taken prior to employing linear mixed model.

Time frame:
Week 5 (End of Intervention Period 1), Week 11 (End of Intervention Period 2) and Week 17 (End of Intervention Period 3) or ET
Reported as:
Least squares mean · units on a scale
Restless Leg Syndrome - Quality of Life Scale (RLS-QoL)
units on a scalePregabalin 300 mgPramipexole 0.5 mgPlacebo
Restless Leg Syndrome - Quality of Life Scale (RLS-QoL)73.30 (69.72 to 76.87)70.05 (66.53 to 73.56)68.03 (64.45 to 71.61)
Statistical analysis
  • Pregabalin 300 mg vs Placebo · Mixed Models Analysis · p = 0.0019 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 5.27 · 95% CI 1.98 to 8.55
  • Pregabalin 300 mg vs Pramipexole 0.5 mg · Mixed Models Analysis · p = 0.0506 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 3.25 · 95% CI -0.01 to 6.51
  • Pramipexole 0.5 mg vs Placebo · Mixed Models Analysis · p = 0.2222 (This analysis was not included in the step-down procedure (if p-value \< 0.05, then continue to next step) to control Type I error.) · Ls mean difference: 2.01 · 95% CI -1.24 to 5.26

Adverse events

Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Pregabalin 300 mg—2/75 (2.7%)46/75 (61.3%)
Pramipexole 0.5 mg—1/76 (1.3%)40/76 (52.6%)
Placebo—3/73 (4.1%)27/73 (37%)
Most frequent serious events
Most frequent serious events
EventPregabalin 300 mgPramipexole 0.5 mgPlacebo
GastroenteritisInfections and infestations0/750/761/73
HypokalaemiaMetabolism and nutrition disorders0/750/761/73
Suicidal ideationPsychiatric disorders0/751/761/73
Blood pressure orthostatic decreasedInvestigations1/750/760/73
Dizziness posturalNervous system disorders1/750/760/73
Deep vein thrombosisVascular disorders1/750/760/73
Most frequent other events
Showing 10 of 116
Most frequent other events
EventPregabalin 300 mgPramipexole 0.5 mgPlacebo
DizzinessNervous system disorders18/752/761/73
SomnolenceNervous system disorders13/756/763/73
NauseaGastrointestinal disorders4/756/761/73
HeadacheNervous system disorders4/756/765/73
Dry mouthGastrointestinal disorders4/752/761/73
Upper respiratory tract infectionInfections and infestations4/752/760/73
Disturbance in attentionNervous system disorders4/750/760/73
Vision blurredEye disorders3/750/760/73
ConstipationGastrointestinal disorders3/751/762/73
Weight increasedInvestigations3/751/760/73

Baseline characteristics

Age, Customized
Age, Customized(participants)Placebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mgTotal
Less than 18 years0000000
18 to 44 years34125318
45 to 64 years8711108852
Greater than or equal to 65 years42232215
Sex: Female, Male
Sex: Female, Male(Participants)Placebo Then Pramipexole 0.5 mg Then Pregabalin 300 mgPramipexole 0.5 mg Then Pregabalin 300 mg Then PlaceboPregabalin 300 mg Then Placebo Then Pramipexole 0.5 mgPregabalin 300 mg Then Pramipexole 0.5 mg Then PlaceboPlacebo Then Pregabalin 300 mg Then Pramipexole 0.5 mgPramipexole 0.5 mg Then Placebo Then Pregabalin 300 mgTotal
Female1178912754
Male46663631
08

Study locations

41 sites
  • Pfizer Investigational Site
    Jasper, Alabama 35501, United States
  • Pfizer Investigational Site
    Phoenix, Arizona 85037, United States
  • Pfizer Investigational Site
    Tucson, Arizona 85712, United States
  • Pfizer Investigational Site
    Little Rock, Arkansas 72205, United States
  • Pfizer Investigational Site
    Little Rock, Arkansas 72211, United States
  • Pfizer Investigational Site
    Burlingame, California 94010, United States
  • Pfizer Investigational Site
    Pasadena, California 91106, United States
  • Pfizer Investigational Site
    Redlands, California 92373, United States
  • Pfizer Investigational Site
    San Diego, California 92103, United States
  • Pfizer Investigational Site
    San Diego, California 92121, United States
  • Pfizer Investigational Site
    Santa Ana, California 92705, United States
  • Pfizer Investigational Site
    Santa Monica, California 90404, United States
  • Pfizer Investigational Site
    Aurora, Colorado 80012, United States
  • Pfizer Investigational Site
    Hallandale Beach, Florida 33009, United States
  • Pfizer Investigational Site
    Miami, Florida 33143, United States
  • Pfizer Investigational Site
    Pembroke Pines, Florida 33026, United States
  • Pfizer Investigational Site
    Spring Hill, Florida 34609, United States
  • Pfizer Investigational Site
    Atlanta, Georgia 30342, United States
  • Pfizer Investigational Site
    Macon, Georgia 31201, United States
  • Pfizer Investigational Site
    Overland Park, Kansas 66212, United States
  • Pfizer Investigational Site
    Crestview Hills, Kentucky 41017, United States
  • Pfizer Investigational Site
    Lexington, Kentucky 40513, United States
  • Pfizer Investigational Site
    Baton Rouge, Louisiana 70809, United States
  • Pfizer Investigational Site
    Chevy Chase, Maryland 20815, United States
  • Pfizer Investigational Site
    Brighton, Massachusetts 02135, United States
  • Pfizer Investigational Site
    Kalamazoo, Michigan 49048, United States
  • Pfizer Investigational Site
    Portage, Michigan 49024, United States
  • Pfizer Investigational Site
    New York, New York 10019, United States
  • Pfizer Investigational Site
    Hickory, North Carolina 28601, United States
  • Pfizer Investigational Site
    Raleigh, North Carolina 27607, United States
  • Pfizer Investigational Site
    Winston-Salem, North Carolina 27103, United States
  • Pfizer Investigational Site
    Cincinnati, Ohio 45227, United States
  • Pfizer Investigational Site
    Dublin, Ohio 43017, United States
  • Pfizer Investigational Site
    Middleburg Heights, Ohio 44130, United States
  • Pfizer Investigational Site
    Oklahoma City, Oklahoma 73112, United States
  • Pfizer Investigational Site
    Clarks Summit, Pennsylvania 18411, United States
  • Pfizer Investigational Site
    Lafayette Hill, Pennsylvania 19444, United States
  • Pfizer Investigational Site
    Columbia, South Carolina 29201, United States
  • Pfizer Investigational Site
    Austin, Texas 78731, United States
  • Pfizer Investigational Site
    Austin, Texas 78756, United States
  • Pfizer Investigational Site
    Dallas, Texas 75231, United States
09

References and documents

Publications

  • Garcia-Borreguero D, Patrick J, DuBrava S, Becker PM, Lankford A, Chen C, Miceli J, Knapp L, Allen RP. Pregabalin versus pramipexole: effects on sleep disturbance in restless legs syndrome. Sleep. 2014 Apr 1;37(4):635-43. doi: 10.5665/sleep.3558. PubMed 24899755 ↗
10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 15, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT00991276
Lead sponsor
Pfizer's Upjohn has merged with Mylan to form Viatris Inc.
Responsible party
Sponsor
First posted
Oct 7, 2009
Start date
Dec 2009
Primary completion
Jun 2011
Completion
Jun 2011
Results posted
Oct 8, 2012
Last update
Feb 15, 2021

Study contacts

Pfizer CT.gov Call Center
study director · Pfizer

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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