Trial · NCT00333359
XP13512 (Gabapentin Enacarbil) Extension Study in Patients With Restless Legs Syndrome.
NCT00333359, Phase 3, Completed, XenoPort, Inc.; results first posted 2011-06-23
3 sourcestrials-2026-11-12-0.5.0
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ConductScience Library. XP13512 (Gabapentin Enacarbil) Extension Study in Patients With Restless Legs Syndrome. Trials, record NCT00333359. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT00333359
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- XP13512 (Gabapentin Enacarbil) Extension Study in Patients With Restless Legs Syndrome.
- NCT number
- NCT00333359
- Status
- Completed
- Phases
- Phase 3
- Enrollment
- 581 participants, actual
- Lead sponsor
- XenoPort, Inc.
- Conditions
- Restless Legs Syndrome
- Interventions
- XP13512 (GEn)
- First posted
- 2006-06-05
- Last updated
- 2013-07-22
- Results first posted
- 2011-06-23
Source ClinicalTrials.gov
Registered outcomes12
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC) | Baseline and Week 52 | The IRLS rating scale is a measure of RLS disease severity. The score reflects participant-reported assessment of primary sensory and motor features and associated sleep problems in RLS. Also, items are included that assess the impact of symptoms on participants' mood, daily life, and activities. The total score on the IRLS ranges from 0 to 40, with higher values representing more severe RLS symptoms. Change from baseline was calculated as the Week 52 value minus the baseline value. Change scores with higher value represents greater improvement in RLS symptoms. |
| Primary | Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Weeks 0, 1, 4, 12, 24, 36, and 52 | The CGI-I is a widely used tool designed to allow clinicians to rate the severity of illness and the change over time based on a seven-point rating scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to the start of the study. Responders on the CGI-I are defined as those with a score of 1 or 2, corresponding to "very much improved" or "improved," respectively. |
| Secondary | Change From Baseline in the IRLS Rating Scale Score at Each Visit Using OC | Weeks 0, 1, 4, 12, 24, and 36 | The IRLS rating scale is a measure of RLS disease severity. The score reflects participant-reported assessment of primary sensory and motor features and associated sleep problems in RLS. Also, items are included that assess the impact of symptoms on participants' mood, daily life, and activities. The total score on the IRLS ranges from 0 to 40, with higher values representing more severe RLS symptoms. Change from baseline was calculated as the value at each visit minus the baseline value. Change scores with higher values represent greater improvement in RLS symptoms. |
| Secondary | Number of Participants in Each Category of the Investigator-rated CGI-I by Visit Using OC | Weeks 0, 1, and 52 | The CGI-I is a widely used tool designed to allow clinicians to rate the severity of illness and the change over time based on a seven-point rating scale, with a score of 1 being "very much improved," 2 being "much improved," 3 being "minimally improved," 4 being "no change," 5 being "minimally worse," 6 being "much worse," and 7 being "very much worse" compared to the start of the study. |
| Secondary | Number of Participants Classified as Responders to Treatment on the Participant-rated CGI-I at Each Visit Using OC | Weeks 0, 1, 4, 12, 24, 36, and 52 | The Participant-rated CGI-I is a self-reported measure completed by the participant, who rates the change from the start of the study in the severity of their illness using a seven-point rating scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse". Responders on the Participant-rated CGI-I are defined as those with a score of 1 or 2, corresponding to "very much improved" and "improved," respectively. |
| Secondary | Number of Participants in Each Category of the Participant-rated CGI-I by Visit Using OC | Weeks 0, 1, and 52 | The Participant-rated CGI-I is a self-reported measure completed by the participant who rates the change from the start of the study in the severity of their illness using a seven-point rating scale, with a score of 1 being "very much improved," 2 being "much improved," 3 being "minimally improved," 4 being "no change," 5 being "minimally worse," 6 being "much worse," and 7 being "very much worse" compared to the start of the study. |
| Secondary | Number of Participants With no Reported RLS Symptoms During Each of the 4-hour Periods From the 24-hour RLS Record at Week 52 Using OC Data | Week 52 | In the 24-Hour RLS Record (diary), participants report the presence and severity of RLS symptoms (none, mild, moderate, or severe) for a 24-hour period, in 30-minute increments. The period was divided into 7 four-hour intervals (8 AM to 12PM, 12 to 4PM, 4 to 8PM, 6 to 10PM, 8 to 12 Midnight, Midnight to 4AM, 4 to 8AM). |
| Secondary | Median Time to Onset of the First RLS Symptom Using the RLS Symptom Record at Weeks 24 and 52 | Weeks 24 and 52 | The 24-Hour RLS Record is a diary in which participants report the presence and severity of RLS symptoms for a 24-hour period, in 30-min increments, beginning at 8AM on the day prior to the visit. |
| Secondary | Overall Quality of Life (QoL) Impact Score of the RLS Quality of Life Questionnaire at Weeks 24 and 52 | Weeks 24 and 52 | The RLS QoL is an 18-item scale assessing the impact of RLS on daily life, emotional well-being, social and work life. Responses range from 1 (not at all/never) to 5 (a lot/all of the time). Ten items contribute to a single summary score, the Overall Life Impact, which is standardized to range from 0-100, with lower scores representing better QoL. |
| Secondary | Mean Change From Baseline at Week 24 and Week 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Summary Scores | Baseline and Weeks 24 and 52 | The WPAI:SHP estimates work productivity and social activities lost over the past week due to RLS symptoms. Each summary score is expressed as a percentage and ranges from 0 to 100, with higher scores indicating more work missed; a negative change from baseline indicates less work missed. Change = the observed value at the current visit minus the observed value at Week 0. Change is calculated only for participants who had a value at both the current visit and at Week 0. |
1 to 10 of 12Source ClinicalTrials.gov
See all 12 registered outcomesOutcomes12
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC) | Baseline and Week 52 | Safety Population: all participants who received one dose or any part of one dose of GEn. Week 52 (end of treatment) results included only Week 52 observed cases and do not include early termination values; as such, the number of participants analyzed differs from the number of participants in the Baseline Characteristics summary. | points on a scale | MEAN |
| PRIMARY | Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Weeks 0, 1, 4, 12, 24, 36, and 52 | Safety Population. Results at each week include only observed cases and do not include early termination values; as such, the number of participants analyzed differs from the number of participants in the Baseline Characteristics summary. | participants | NUMBER |
| SECONDARY | Change From Baseline in the IRLS Rating Scale Score at Each Visit Using OC | Weeks 0, 1, 4, 12, 24, and 36 | Safety Population. Results at each week include only observed cases and do not include early termination values; as such, the number of participants analyzed differs from the number of participants in the Baseline Characteristics summary. | points on a scale | MEAN |
| SECONDARY | Number of Participants in Each Category of the Investigator-rated CGI-I by Visit Using OC | Weeks 0, 1, and 52 | Safety Population. Results at each week include only observed cases and do not include early termination values; as such, the number of participants analyzed differs from the number of participants in the Baseline Characteristics summary. | participants | NUMBER |
| SECONDARY | Number of Participants Classified as Responders to Treatment on the Participant-rated CGI-I at Each Visit Using OC | Weeks 0, 1, 4, 12, 24, 36, and 52 | Safety Population. Results at each week include only observed cases and do not include early termination values; as such, the number of participants analyzed at each week differs from the number of participants in the Baseline Characteristics summary. | participants | NUMBER |
| SECONDARY | Number of Participants in Each Category of the Participant-rated CGI-I by Visit Using OC | Weeks 0, 1, and 52 | Safety Population. Results at each week include only observed cases and do not include early termination values; as such, the number of participants analyzed differs from the number of participants in the Baseline Characteristics summary. | participants | NUMBER |
| SECONDARY | Number of Participants With no Reported RLS Symptoms During Each of the 4-hour Periods From the 24-hour RLS Record at Week 52 Using OC Data | Week 52 | Safety Population. Results at Week 52 include only Week 52 observed cases and do not include early termination values; as such, the number of participants with data at each time point differs from the number of participants in the Baseline Characteristics summary. | participants | NUMBER |
| SECONDARY | Median Time to Onset of the First RLS Symptom Using the RLS Symptom Record at Weeks 24 and 52 | Weeks 24 and 52 | Safety Population. Results include only observed cases and do not include early termination values; as such, the number of participants analyzed at each week differs from the number of participants in the Baseline Characteristics summary. | hours | MEDIAN |
| SECONDARY | Overall Quality of Life (QoL) Impact Score of the RLS Quality of Life Questionnaire at Weeks 24 and 52 | Weeks 24 and 52 | Safety Population. Results include only observed cases and do not include early termination values; as such, the number of participants analyzed at each week differs from the number of participants in the Baseline Characteristics summary. | points on a scale | MEAN |
| SECONDARY | Mean Change From Baseline at Week 24 and Week 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Summary Scores | Baseline and Weeks 24 and 52 | Safety Population. Results include only observed cases and do not include early termination values; as such, the number of participants analyzed at each week differs from the number of participants in the Baseline Characteristics summary. | percent change | MEAN |
1 to 10 of 12Source ClinicalTrials.gov
See all 12 outcomesResults by group270
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC) | Naïve; 1200 mg GEn | -16.3 | Standard Deviation 8.23 | points on a scale | |
| Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC) | Non-naïve; 1200 mg GEn | -17.0 | Standard Deviation 8.20 | points on a scale | |
| Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC) | All Participants; 1200 mg GEn | -16.8 | Standard Deviation 8.21 | points on a scale | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Naïve; 1200 mg GEn | Week 0, n=197, 376, 573 | 84 | participants | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Non-naïve; 1200 mg GEn | Week 0, n=197, 376, 573 | 300 | participants | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | All Participants; 1200 mg GEn | Week 0, n=197, 376, 573 | 384 | participants | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Naïve; 1200 mg GEn | Week 1, n=185, 363, 548 | 152 | participants | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Non-naïve; 1200 mg GEn | Week 1, n=185, 363, 548 | 294 | participants | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | All Participants; 1200 mg GEn | Week 1, n=185, 363, 548 | 446 | participants | |
| Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC | Naïve; 1200 mg GEn | Week 4, n=171, 354, 525 | 143 | participants |
1 to 10 of 270Source ClinicalTrials.gov
See all 270 results by groupParticipant flow6
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Naïve; 1200 mg GEn | 199 | |
| Overall Study | STARTED | Non-naïve; 1200 mg GEn | 382 | |
| Overall Study | COMPLETED | Naïve; 1200 mg GEn | 126 | |
| Overall Study | COMPLETED | Non-naïve; 1200 mg GEn | 260 | |
| Overall Study | NOT COMPLETED | Naïve; 1200 mg GEn | 73 | |
| Overall Study | NOT COMPLETED | Non-naïve; 1200 mg GEn | 122 |
Source ClinicalTrials.gov
Adverse events99
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Somnolence | Nervous system disorders | Naïve; 1200 mg GEn | 54 | 197 | |
| other | Somnolence | Nervous system disorders | Non-naïve; 1200 mg GEn | 59 | 376 | |
| other | Somnolence | Nervous system disorders | All Participants; 1200 mg GEn | 113 | 573 | |
| other | Dizziness | Nervous system disorders | Naïve; 1200 mg GEn | 39 | 197 | |
| other | Dizziness | Nervous system disorders | Non-naïve; 1200 mg GEn | 27 | 376 | |
| other | Dizziness | Nervous system disorders | All Participants; 1200 mg GEn | 66 | 573 | |
| other | Headache | Nervous system disorders | Naïve; 1200 mg GEn | 15 | 197 | |
| other | Headache | Nervous system disorders | Non-naïve; 1200 mg GEn | 26 | 376 | |
| other | Headache | Nervous system disorders | All Participants; 1200 mg GEn | 41 | 573 | |
| other | Fatigue | General disorders | Naïve; 1200 mg GEn | 15 | 197 |
1 to 10 of 99Source ClinicalTrials.gov
See all 99 adverse eventsAdverse event totals9
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Naïve; 1200 mg GEn | ||
| Total, all-cause mortality | Non-naïve; 1200 mg GEn | ||
| Total, all-cause mortality | All Participants; 1200 mg GEn | ||
| Total, other adverse events | Naïve; 1200 mg GEn | 114 | 197 |
| Total, other adverse events | Non-naïve; 1200 mg GEn | 144 | 376 |
| Total, other adverse events | All Participants; 1200 mg GEn | 258 | 573 |
| Total, serious adverse events | Naïve; 1200 mg GEn | 7 | 197 |
| Total, serious adverse events | Non-naïve; 1200 mg GEn | 14 | 376 |
| Total, serious adverse events | All Participants; 1200 mg GEn | 21 | 573 |
Source ClinicalTrials.gov
Papers1
The papers the trial lists on ClinicalTrials.gov.
| PMID | Listed as |
|---|---|
| 21242741 | BACKGROUND |
Source PubMed
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
None in this release.
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
GET https://conductscience.org/api/trials/v1/NCT00333359
GET https://conductscience.org/api/trials/v1/NCT00333359/results?page=2