XP13512 vs. Placebo in Patients With Restless Legs Syndrome.

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
XenoPort, Inc.
ClinicalTrials.gov Identifier:
NCT00365352
First received: August 15, 2006
Last updated: July 15, 2013
Last verified: May 2011
Results First Received: April 21, 2011  
Study Type: Interventional
Study Design: Allocation: Randomized;   Endpoint Classification: Safety/Efficacy Study;   Intervention Model: Parallel Assignment;   Masking: Double Blind (Subject, Investigator);   Primary Purpose: Treatment
Condition: Restless Legs Syndrome
Interventions: Drug: XP13512 600MG
Drug: XP13512 1200MG
Drug: PLACEBO

  Participant Flow
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Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
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Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
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Reporting Groups
  Description
Placebo Oral placebo tablet taken once daily. Days 1 to 3: one placebo tablet. Days 4 to 84: two placebo tablets. On Days 85 participants entered a 7-day Taper Period. Days 85 to 91: one placebo tablet.
GEn (XP13512/GSK1838262) 600 mg Gabapentin enacarbil (GEn) (XP13512/GSK1838262) 600 milligrams (mg) taken orally once a day for 12 weeks) taken once daily. Days 1 to 3: one extended release (ER) tablet (600 mg GEn). Days 4 to 84: one ER tablet (600 mg GEn) and one placebo tablet. On Day 85, participants entered a 7-day Taper Period. Days 85 to 91: one placebo tablet.
GEn (XP13512/GSK1838262) 1200 mg Oral GEn (gabapentin enacarbil) 1200 milligrams (mg) taken once daily. Days 1 to 3: one extended release (ER) tablet (600 mg GEn). Days 4 to 84: two ER tablets (1200 mg GEn). On Day 85, participants entered a 7-day Taper Period. Days 85 to 91: one ER tablet (600 mg GEn).

Participant Flow:   Overall Study
    Placebo     GEn (XP13512/GSK1838262) 600 mg     GEn (XP13512/GSK1838262) 1200 mg  
STARTED     97     115     113  
Safety Population     96     115     111  
Modified Intent-to-Treat Population     96     114     111  
COMPLETED     77     104     98  
NOT COMPLETED     20     11     15  
Adverse Event                 6                 7                 8  
Participant Withdrew Consent                 8                 3                 4  
Lack of Efficacy                 3                 0                 0  
Ineligible (Did Not Meet Entry Criteria)                 0                 0                 2  
Non-Compliance (after Randomization)                 1                 0                 1  
Lost to Follow-up                 1                 1                 0  
Withdrawal of Participant by Sponsor                 1                 0                 0  



  Baseline Characteristics
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Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
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Reporting Groups
  Description
Placebo Oral placebo tablet taken once daily. Days 1 to 3: one placebo tablet. Days 4 to 84: two placebo tablets. On Days 85 participants entered a 7-day Taper Period. Days 85 to 91: one placebo tablet.
GEn (XP13512/GSK1838262) 600 mg Gabapentin enacarbil (GEn) (XP13512/GSK1838262) 600 milligrams (mg) taken orally once a day for 12 weeks) taken once daily. Days 1 to 3: one extended release (ER) tablet (600 mg GEn). Days 4 to 84: one ER tablet (600 mg GEn) and one placebo tablet. On Day 85, participants entered a 7-day Taper Period. Days 85 to 91: one placebo tablet.
GEn (XP13512/GSK1838262) 1200 mg Oral GEn (gabapentin enacarbil) 1200 milligrams (mg) taken once daily. Days 1 to 3: one extended release (ER) tablet (600 mg GEn). Days 4 to 84: two ER tablets (1200 mg GEn). On Day 85, participants entered a 7-day Taper Period. Days 85 to 91: one ER tablet (600 mg GEn).
Total Total of all reporting groups

Baseline Measures
    Placebo     GEn (XP13512/GSK1838262) 600 mg     GEn (XP13512/GSK1838262) 1200 mg     Total  
Number of Participants  
[units: participants]
  96     114     111     321  
Age [1]
[units: Years]
Mean ± Standard Deviation
  49.1  ± 12.19     48.3  ± 12.88     49.5  ± 12.67     48.9  ± 12.58  
Gender [2]
[units: Participants]
       
Female     57     66     65     188  
Male     39     48     46     133  
Race/Ethnicity, Customized [3]
[units: participants]
       
American Indian or Alaskan Native     1     3     0     4  
Asian     2     0     1     3  
Black or African American     1     5     1     7  
Native Hawaiian or Other Pacific Islander     1     0     0     1  
White or Caucasian     92     106     107     305  
Unknown     0     2     2     4  
[1] Baseline Characteristics were collected from members of the Modified Intent-to-Treat (MITT) Population, comprised of all participants in the Safety Population who also satisfied both of the following conditions: (1) completed the International Restless Legs Syndrome (IRLS) Rating Scale at Baseline; and (2) completed at least one on-treatment IRLS Rating Scale score during the treatment period.
[2] Baseline Characteristics were collected for members of the Modified Intent-to-Treat (MITT) Population, comprised of all participants in the Safety Population who also satisfied both of the following conditions: (1) completed the International Restless Legs Syndrome (IRLS) Rating Scale at Baseline; and (2) completed at least one on-treatment IRLS Rating Scale score during the treatment period.
[3] Baseline Characteristics were collected in members of the Modified Intent-to-Treat (MITT) Population, comprised of all participants in the Safety Population who also satisfied both of the following conditions: (1) completed the International Restless Legs Syndrome (IRLS) Rating Scale at Baseline; and (2) completed at least one on-treatment IRLS Rating Scale score during the treatment period. Patients were allowed to categorize to more than one race.



  Outcome Measures
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1.  Primary:   Change From Baseline in IRLS Rating Scale Total Score at Week 12 Using Last Observation Carried Forward (LOCF)   [ Time Frame: Baseline and Week 12 ]

2.  Primary:   Number of Participants With a Score of "Much Improved" or "Very Much Improved" on the Investigator-rated CGI-I Scale (Response) at (Week 12) Using LOCF   [ Time Frame: Week 12 ]

3.  Secondary:   Change From Baseline to the End of Treatment (Week 12) in the IRLS Rating Scale Total Score Using LOCF   [ Time Frame: Baseline (Day 1) and End of Treatment (Week 12) ]

4.  Secondary:   Number of Participants Classsified as Responders on the Investigator-rated CGI-I Scale at Week 12 Using LOCF   [ Time Frame: Week 12 ]

5.  Secondary:   Number of Participants Who Had an Onset of Response to Treatment at the End of Week 1 Based Upon the IRLS Rating Scale Total Score and the Investigator-rated CGI-I Using LOCF   [ Time Frame: End of Week 1 ]

6.  Secondary:   The Time to Onset of the First Response to Treatment on the IRLS Rating Scale Total Score and the Investigator-rated CGI-I   [ Time Frame: Baseline (Day 1) to End of Treatment (Week 12) ]

7.  Secondary:   Mean Change in the IRLS Rating Scale Total Score From Baseline at Week 12 by RLS Treatment History Using LOCF   [ Time Frame: Baseline (Day 1) and Week 12 ]

8.  Secondary:   Change From Baseline in the IRLS Rating Scale Total Score at Week 12 by Baseline RLS Rating Scale Total Score Category (Baseline RLS Severity) Using LOCF   [ Time Frame: Baseline (Day 1) and Week 12 ]

9.  Secondary:   Change From Baseline to the End of Week 1 in the IRLS Rating Scale Total Score Using LOCF   [ Time Frame: Baseline and the End of Week 1 ]

10.  Secondary:   Number of Participants Classified as Investigator-rated CGI-I Scale Responders at Week 12 by RLS Treatment History Using LOCF   [ Time Frame: Basline and Week 12 ]

11.  Secondary:   Number of Total Responders to Treatment Based on the Investigator-Rated CGI of Improvement at the End of One Week of Treatment   [ Time Frame: End of Week 1 ]

12.  Secondary:   Change From Baseline to the End of Treatment in Average Daily Total Sleep Time (Hours) Using LOCF   [ Time Frame: Baseline to End of Treatment (Week 12) ]

13.  Secondary:   Change From Baseline to the End of Treatment in Average Daily Wake Time (Minutes) After Sleep Onset Using LOCF   [ Time Frame: Baseline to End of Treatment (Week 12) ]

14.  Secondary:   Change From Baseline in the Average Daily RLS Pain Score at the End of Treatment (Week 12) for Participants With Pain at Baseline or the End of Week 12 Using LOCF   [ Time Frame: Baseline and End of Treatment (Week 12) ]

15.  Secondary:   Number of Participants Classified as Responders With at Least 30% and 50% Improvement in the Average Daily RLS Pain Score Using LOCF   [ Time Frame: Week 12 ]

16.  Secondary:   Change From Baseline in the Average Daily RLS Pain Score to Week 12 for Participants With a Baseline Pain Score of at Least 4 Using LOCF   [ Time Frame: Baseline and Week 12 ]

17.  Secondary:   Number of Participants Classified as Responders to Treatment Based on the Participant-Rated CGI of Improvement at Week 1 and Week 12 (End of Treatment)   [ Time Frame: Week 1 and Week 12 ]

18.  Secondary:   Number of Participants With a Rating of Excellent for the Overall Quality of Sleep in Past Week Measured by the Post-Sleep Questionnaire (PSQ) at the End of Treatment (Week 12) Using LOCF   [ Time Frame: End of Treatment (Week 12) ]

19.  Secondary:   Number of Participants Who Indicated on the Mood Assessment That Their Mood Was Much Improved or Very Much Improved at Week 12 (End of Treatment) Using LOCF   [ Time Frame: Week 12 ]

20.  Secondary:   Change From Baseline in the Profile of Mood State (POMS) Scale at Week 12 Using LOCF   [ Time Frame: Baseline to End of Treatment (Week 12) ]

21.  Secondary:   Change From Baseline in the Daytime Somnolence Score, an Item on the Medical Outcomes Study (MOS) Sleep Scale, at Week 12 Using LOCF   [ Time Frame: Baseline and Week 12 ]

22.  Secondary:   Change From Baseline in the Sleep Disturbance Score, an Item on the MOS Sleep Scale, at Week 12 Using LOCF   [ Time Frame: Baseline and Week 12 ]

23.  Secondary:   Change From Baseline in Sleep Adequacy, an Item on the MOS Sleep Scale, at Week 12 Using LOCF   [ Time Frame: Basline and Week 12 ]

24.  Secondary:   Change From Baseline in Sleep Quantity, an Item on the MOS Sleep Scale, at Week 12 Using LOCF   [ Time Frame: Baseline and Week 12 ]

25.  Secondary:   Change From Baseline in the Overall Life-Impact Score of the RLS Quality of Life (QoL) Questionnaire at Week 12 Using LOCF   [ Time Frame: Baseline and Week 12 ]

26.  Secondary:   Number of Participants Experiencing No RLS Symptoms in Each of the Seven 4-hour Periods From the 24-hour RLS Record at Week 12 (End of Treatment)   [ Time Frame: Week 12 ]

27.  Secondary:   Time to Onset of the First RLS Symptom From the 24-hour RLS Record Obtained at the End of Treatment (Week 12)   [ Time Frame: Week 12 ]


  Serious Adverse Events


  Other Adverse Events


  Limitations and Caveats
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Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
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  More Information
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Certain Agreements:  
Principal Investigators are NOT employed by the organization sponsoring the study.
There IS an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
The agreement is:
unchecked The only disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is less than or equal to 60 days. The sponsor cannot require changes to the communication and cannot extend the embargo.
unchecked The only disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is more than 60 days but less than or equal to 180 days. The sponsor cannot require changes to the communication and cannot extend the embargo.


Results Point of Contact:  
Name/Title: XenoPort Call Center
Organization: XenoPort, Inc.
phone: 877-936-6778


No publications provided by XenoPort, Inc.

Publications automatically indexed to this study:

Responsible Party: XenoPort, Inc.
ClinicalTrials.gov Identifier: NCT00365352     History of Changes
Other Study ID Numbers: 111460, XP053
Study First Received: August 15, 2006
Results First Received: April 21, 2011
Last Updated: July 15, 2013
Health Authority: United States: Food and Drug Administration