Restless Legs SyndromePhase 3NCT00311363
Long-Term Study of Gabapentin Enacarbil (GEn, XP13512) vs. Placebo in Patients With Restless Legs Syndrome.
A Phase 3 study testing GEn (XP13512) in people with Restless Legs Syndrome, run by XenoPort, Inc..
Trial summary
The primary objective of this trial is to assess the maintenance of efficacy of gabapentin enacarbil (GEn, XP13512) taken once daily in the long-term treatment of patients suffering from Restless Legs Syndrome (RLS). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Restless Legs Syndrome
- What is being tested?
- GEn (XP13512)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 327 participants
- Where
- No sites listed yet
- Study dates
- Apr 2006to Nov 2007
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients with primary RLS, based on the International RLS Study Group Diagnostic Criteria.
Who cannot join
- A sleep disorder (e.g., sleep apnea) that may significantly affect the assessment of RLS;
- Neurologic disease or movement disorder (e.g., diabetic neuropathy, Parkinson's disease, Multiple Sclerosis, dyskinesias, and dystonias);
- Abnormal laboratory results, electrocardiogram (ECG) or physical findings;
- Pregnant or lactating women;
- Women of childbearing potential who are not practicing an acceptable method of birth control.
About this study
Official title: A Long-Term Study of XP13512 Versus Placebo Treatment Assessing Maintenance of Efficacy and Safety in Patients With Restless Legs Syndrome.
The primary objective of this trial is to assess the maintenance of efficacy of gabapentin enacarbil (GEn, XP13512) taken once daily in the long-term treatment of patients suffering from Restless Legs Syndrome (RLS).
Read the detailed description
This study was a multicenter, blinded, randomized withdrawal study in subjects with primary Restless Legs Syndrome (RLS). Eligible subjects were initially enrolled in a 24-week single blind (SB) treatment period during which they received XP13512. Subjects who completed the initial treatment period and met the responder criteria were then randomized 1:1 to receive either XP13512 or placebo during the 12-week double-blind (DB) treatment period. The primary study objective was to assess the maintenance of efficacy of XP13512 1200 mg taken once daily in the long-term treatment of subjects with primary RLS. The secondary study objectives were to assess maintenance of improvements in sleep outcomes and quality of life, and to assess the safety and tolerability of XP13512 in the treatment of primary RLS subjects.
- Conditions
- Restless Legs Syndrome
- Being tested
- GEn (XP13512), Placebo
- Medical subject headings
- Restless Legs Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GEn (XP13512)Drug
Also called Gabapentin Enacabil, XP13512
1200 mg GEn (XP13512) orally, once daily for 24 weeks followed by either 1200 mg GEn (XP13512) or placebo, orally, once daily for an additional 12 weeks
GEn (XP13512)Drug
Also called Gabapentin Enacarbil, XP13512
1200 mg GEn (XP13512), orally, once daily for 24 weeks followed by either 1200 mg GEn (XP13512) or placebo, orally, once daily for an additional 12 weeks
PlaceboDrug
Placebo, orally, once daily for 12 weeks following single blind 24-week phase
| Study group | Role | What they receive |
|---|---|---|
| GEn (XP13512) 1200 mg | Experimental | GEn (XP13512) 1200 mg Receives: Drug: GEn (XP13512) |
| Placebo | Placebo comparator | Placebo Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants Who Experienced a Relapse During the Double-Blind Treatment Period
Relapse was defined as worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week double-blind (DB) treatment period (the period from Randomization on Visit 14 [Week 24] through the end of treatment). Worsening of symptoms was defined as an increase in the total International RLS (IRLS) Scale score by at least 6 or more points relative to the participant's score at Randomization, achieving an IRLS score of at least 15, and an assessment of "much worse" or "very much worse" on the investigator-rated Clinical Global Impression of Change (CGI-C).
Measured: DB Treatment Period; Days 169 to 252 (Weeks 24 to 36)
Secondary outcomes (32)
Time From Randomization to Relapse in RLS Symptoms During the Double-Blind Treatment Period
Time to relapse was defined as the time until worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week Double-blind (DB) treatment period (same as primary outcome definition). Note: The median is not estimable with Kaplan-Meier methodology when fewer than 50% of participants experience an event. The median is not estimable for this outcome.
Measured: DB Treatment Period; Days 169 to 252 (Weeks 24 to 36)
Time From Randomization to Relapse in RLS Symptoms During the Double-Blind Treatment Period (Excluding First Two Weeks of DB Phase)
Time to relapse was defined as the time until worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week Double-blind (DB) treatment period (same as primary outcome definition). Note: The median is not estimable with Kaplan-Meier methodology when fewer than 50% of participants experience an event. The median is not estimable for this outcome.
Measured: DB Treatment Period; Days 184 to 252 (Weeks 26 to 36)
Mean Change From Randomization to Week 36 (or End of Treatment) in the IRLS Rating Scale (IRLS) Total Score Using Last Observation Carried Forward (LOCF)
The IRLS Rating scale is a measure of RLS disease severity and reflects the participant-reported assessment of primary sensory and motor features and associated sleep problems in RLS. Items are included that assess the impact of symptoms on participants' mood, daily life, and activities. The total score ranges from 0-40 points, with 40 being the most severe. The scale assesses symptoms over the week prior to measurement. LOCF: Missing data (MD) values were imputed using the last non-missing observation prior to the visit with MD; randomization visit data could be carried forward.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Percentage of Participants Who Responded to Treatment Based on Scores on the Investigator-Rated Clinical Global Impression of Change (CGI-C) Scale as a Dichotomous Variable at Week 36 (DB Treatment Phase) Using LOCF
The CGI-C scale 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 baseline. For this endpoint, "response" on the CGI-C was defined as participants with a rating of "no change," (score of 4) "minimally improved," (score of 3) "much improved," (score of 2) or "very much improved" (score of 1) compared to Randomization (Week 24).
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants in Each Category of the Investigator-Rated CGI-C at Week 36 (DB Treatment Phase) Using LOCF
The CGI scale 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 baseline.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants in Each Category of the Participant-Rated CGI-I Scale at Week 36 (DB Treatment Phase) Using LOCF
The participant-rated CGI-I scale is a self-rated assessment designed to allow participants to rate the change of their disease severity over time based on a seven-point scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to baseline.
Measured: Week 36 (or end of DB treatment)
Percentage of Participants Who Responded to Treatment Based on Scores on the Participant-Rated CGI-I at Week 36 (DB Treatment Phase) Using LOCF
The participant-rated CGI-I scale is a self-rated assessment designed to allow participants to rate the change of their disease severity over time based on a seven-point scale, with a score of 1 being "very much improved," and a score of 7 being "very much worse." Response on the participant-rated CGI-I was defined as a rating of "very much improved" (score of 1) or "much improved" (score of 2) compared to Baseline of the SB phase.
Measured: Week 36 (or end of DB treatment)
Mean Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Daytime Somnolence Domain Score of the Medical Outcomes Study (MOS) Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. Responses are recoded so that a higher score reflects more of the attribute, and then converted to a 0 to 100 scale. The daytime somnolence score is based on questions pertaining to feeling drowsy or sleepy, trouble staying awake, and taking naps > 5 minutes. For daytime somnolence, a negative value indicates an improvement.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Mean Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Sleep Disturbance Domain Score of the MOS Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The MOS Sleep Scale sleep disturbance domain is a participant-rated measure of sleep disturbance over the month prior to the measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with lower scores representing less sleep disturbance.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Sleep Adequacy Domain Score of the MOS Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The MOS Sleep Scale sleep adequacy domain is a participant-rated measure of the adequacy of sleep over the month prior to measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with higher scores representing more adequate ratings of sleep.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Sleep Quantity Domain Score of the MOS Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The Sleep Quantity Domain score is a participant-rated estimate of the average number of hours of sleep per night over the month.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Change From Randomization to Week 36 (DB Treatment Phase) in the RLS Quality of Life (QoL) Overall Life-Impact Score
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.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With no Reported RLS Symptoms (Sx) During Each of the 4-hour Periods From the 24-hour RLS Record at Week 36 (DB Treatment Phase)
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-hr intervals (8 AM to 12 PM, 12 to 4 PM, 4 to 8 PM, 6 to 10 PM, 8 to Midnight, Midnight to 4 AM, 4 to 8 AM)
Measured: Week 36 (or end of DB treatment)
Median Time to Onset of First RLS Symptoms Using the 24-hour RLS Symptom Record at Week 36 (DB Treatment Phase)
The 24-hour RLS Record is a diary in which participants report the presence and severity of RLS symptoms (none, mild, moderate, or severe) for a 24-hour period, in 30-min increments beginning at 8AM on the day prior to the visit. Note: The median is not estimable with Kaplan-Meier methodology when fewer than 50% of participants experience an event; thus, no data are presented for the DB GEn 1200 mg arm.
Measured: Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire (PSQ) Responses to the Question Regarding Their Overall Quality of Sleep in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire (PSQ) Responses to the Question Regarding Their Ability to Function in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Nights With RLS Symptoms in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Awakenings During Night Due to RLS Symptoms in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Hours Awake Per Night Due to RLS Symptoms in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Randomization (Week 24) and Week 36 (or end of DB treatment)
Mean Change From Baseline in the IRLS Scale Total Score at Week 24 (SB Treatment Phase) Using LOCF
The IRLS Rating scale is a measure of disease severity. The scale reflects participant-reported assessment of sensory and motor features and associated sleep problems in RLS. In addition, items are included that assess the impact of symptoms on participants' mood, daily life, and activities. Total score ranges from 0-40 points, with 40 being the most severe.
Measured: Days 1 to 168 (Baseline to Week 24 of SB Phase)
Number of Participants in Each Category of the Investigator-Rated CGI-I at Week 24/End of Treatment (SB Treatment Phase) Using LOCF
The CGI-I scale 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 baseline.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants in Each Category of the Participant-Rated CGI-I at Week 24/End of Treatment (SB Treatment Phase) Using LOCF
The participant-rated CGI-I scale is a self-rated assessment designed to allow participants to rate the change of their disease severity 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 baseline.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline to Week 24 (SB Treatment Period) in the Mean Daytime Somnolence Domain Score of the Medical Outcomes Study (MOS) Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. Responses are recoded so that a higher score reflects more of the attribute, and then converted to a 0 to 100 scale. The daytime somnolence score is based on questions pertaining to feeling drowsy or sleepy, trouble staying awake, and taking naps > 5 minutes. For daytime somnolence, a negative value indicates an improvement.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline to Week 24 (SB Treatment Period) in the Mean Sleep Disturbance Domain Score of the MOS Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. . The MOS Sleep Scale sleep disturbance domain is a participant-rated measure of sleep disturbance over the month prior to the measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with lower scores representing less sleep disturbance.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline to Week 24 (SB Treatment Period) in the Mean Sleep Adequacy Domain Score of the MOS Sleep Scale Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The MOS Sleep Scale sleep adequacy domain is a participant-rated measure of the adequacy of sleep over the month prior to measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with higher scores representing more adequate ratings of sleep.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline in the MOS Sleep Scale Domain, Sleep Quantity, Score at Week 24 (SB Treatment Period) Using LOCF
The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and somnolence. The Sleep Quantity Domain score is a participant-rated estimate of the average number of hours of sleep per night over the month.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline in the Overall Quality of Life Impact Score of the RLS Quality of Life (QoL) Questionnaire at Week 24 (SB Treatment Phase)
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.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Overall Quality of Sleep in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Ability to Function in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Nights With RLS Symptoms in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Awakenings During the Night Due to RLS Symptoms in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Hours Awake Per Night Due to RLS Symptoms in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.
Measured: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Apr 2006 (estimated)
- Study startApr 2006
- Primary completionNov 2007
- Study completionNov 2007
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Restless Legs SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 327 participants (actual)
Sponsor and investigators
- Lead sponsor
- XenoPort, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- GSK Clinical Trials, Study director, GlaxoSmithKline
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00311363
- Sponsor's protocol ID
- 111461
- Other IDs
- XP060
- Status last verified
- May 2011
- First submitted
- 3 Apr 2006
- Last updated
- 22 Jul 2013
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Bogan RK, Bornemann MA, Kushida CA, Tran PV, Barrett RW; XP060 Study Group. Long-term maintenance treatment of restless legs syndrome with gabapentin enacarbil: a randomized controlled study. Mayo Clin Proc. 2010 Jun;85(6):512-21. doi: 10.4065/mcp.2009.0700.
PubMed 20511481
Study at a glance
From the registry record, last updated by the sponsor on 22 Jul 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Long-Term Study of XP13512 Versus Placebo Treatment Assessing Maintenance of Efficacy and Safety in Patients With Restless Legs Syndrome.
- ClinicalTrials.gov ID
- NCT00311363
- Acronym / sponsor ID
- 111461
- Conditions
- Restless Legs Syndrome
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 327 participants (actual)
- Lead sponsor
- XenoPort, Inc.Industry (pharma, biotech, devices)
- Study start
- Apr 2006
- Primary completion
- Nov 2007 (actual)
- Study completion
- Nov 2007 (actual)
- First posted
- 5 Apr 2006 (estimated)
- Results
- Posted 25 May 2011
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective of this trial is to assess the maintenance of efficacy of gabapentin enacarbil (GEn, XP13512) taken once daily in the long-term treatment of patients suffering from Restless Legs Syndrome (RLS).
Detailed description
This study was a multicenter, blinded, randomized withdrawal study in subjects with primary Restless Legs Syndrome (RLS). Eligible subjects were initially enrolled in a 24-week single blind (SB) treatment period during which they received XP13512. Subjects who completed the initial treatment period and met the responder criteria were then randomized 1:1 to receive either XP13512 or placebo during the 12-week double-blind (DB) treatment period. The primary study objective was to assess the maintenance of efficacy of XP13512 1200 mg taken once daily in the long-term treatment of subjects with primary RLS. The secondary study objectives were to assess maintenance of improvements in sleep outcomes and quality of life, and to assess the safety and tolerability of XP13512 in the treatment of primary RLS subjects.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| GEn (XP13512) 1200 mg | Experimental | Drug: GEn (XP13512)GEn (XP13512) 1200 mg |
| Placebo | Placebo comparator | Drug: PlaceboPlacebo |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Patients with primary RLS, based on the International RLS Study Group Diagnostic Criteria.
Key exclusion criteria (5 listed)
- A sleep disorder (e.g., sleep apnea) that may significantly affect the assessment of RLS;
- Neurologic disease or movement disorder (e.g., diabetic neuropathy, Parkinson's disease, Multiple Sclerosis, dyskinesias, and dystonias);
- Abnormal laboratory results, electrocardiogram (ECG) or physical findings;
- Pregnant or lactating women;
- Women of childbearing potential who are not practicing an acceptable method of birth control.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GEn (XP13512)Also: Gabapentin Enacabil, XP135121200 mg GEn (XP13512) orally, once daily for 24 weeks followed by either 1200 mg GEn (XP13512) or placebo, orally, once daily for an additional 12 weeks | Drug | GEn (XP13512) 1200 mg |
| GEn (XP13512)Also: Gabapentin Enacarbil, XP135121200 mg GEn (XP13512), orally, once daily for 24 weeks followed by either 1200 mg GEn (XP13512) or placebo, orally, once daily for an additional 12 weeks | Drug | GEn (XP13512) 1200 mg |
| PlaceboPlacebo, orally, once daily for 12 weeks following single blind 24-week phase | Drug | Placebo |
Primary outcome
Percentage of Participants Who Experienced a Relapse During the Double-Blind Treatment Period
Time frame: DB Treatment Period; Days 169 to 252 (Weeks 24 to 36)
Relapse was defined as worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week double-blind (DB) treatment period (the period from Randomization on Visit 14 [Week 24] through the end of treatment). Worsening of symptoms was defined as an increase in the total International RLS (IRLS) Scale score by at least 6 or more points relative to the participant's score at Randomization, achieving an IRLS score of at least 15, and an assessment of "much worse" or "very much worse" on the investigator-rated Clinical Global Impression of Change (CGI-C).
32 secondary outcomes
Time From Randomization to Relapse in RLS Symptoms During the Double-Blind Treatment Period
Time frame: DB Treatment Period; Days 169 to 252 (Weeks 24 to 36)
Time From Randomization to Relapse in RLS Symptoms During the Double-Blind Treatment Period (Excluding First Two Weeks of DB Phase)
Time frame: DB Treatment Period; Days 184 to 252 (Weeks 26 to 36)
Mean Change From Randomization to Week 36 (or End of Treatment) in the IRLS Rating Scale (IRLS) Total Score Using Last Observation Carried Forward (LOCF)
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Percentage of Participants Who Responded to Treatment Based on Scores on the Investigator-Rated Clinical Global Impression of Change (CGI-C) Scale as a Dichotomous Variable at Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants in Each Category of the Investigator-Rated CGI-C at Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants in Each Category of the Participant-Rated CGI-I Scale at Week 36 (DB Treatment Phase) Using LOCF
Time frame: Week 36 (or end of DB treatment)
Percentage of Participants Who Responded to Treatment Based on Scores on the Participant-Rated CGI-I at Week 36 (DB Treatment Phase) Using LOCF
Time frame: Week 36 (or end of DB treatment)
Mean Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Daytime Somnolence Domain Score of the Medical Outcomes Study (MOS) Sleep Scale Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Mean Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Sleep Disturbance Domain Score of the MOS Sleep Scale Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Sleep Adequacy Domain Score of the MOS Sleep Scale Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Change From Randomization to Week 36 (DB Treatment Phase) in the Mean Sleep Quantity Domain Score of the MOS Sleep Scale Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Change From Randomization to Week 36 (DB Treatment Phase) in the RLS Quality of Life (QoL) Overall Life-Impact Score
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With no Reported RLS Symptoms (Sx) During Each of the 4-hour Periods From the 24-hour RLS Record at Week 36 (DB Treatment Phase)
Time frame: Week 36 (or end of DB treatment)
Median Time to Onset of First RLS Symptoms Using the 24-hour RLS Symptom Record at Week 36 (DB Treatment Phase)
Time frame: Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire (PSQ) Responses to the Question Regarding Their Overall Quality of Sleep in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire (PSQ) Responses to the Question Regarding Their Ability to Function in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Nights With RLS Symptoms in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Awakenings During Night Due to RLS Symptoms in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Hours Awake Per Night Due to RLS Symptoms in the Week Prior to Measurement at Randomization and Week 36 (DB Treatment Phase) Using LOCF
Time frame: Randomization (Week 24) and Week 36 (or end of DB treatment)
Mean Change From Baseline in the IRLS Scale Total Score at Week 24 (SB Treatment Phase) Using LOCF
Time frame: Days 1 to 168 (Baseline to Week 24 of SB Phase)
Number of Participants in Each Category of the Investigator-Rated CGI-I at Week 24/End of Treatment (SB Treatment Phase) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants in Each Category of the Participant-Rated CGI-I at Week 24/End of Treatment (SB Treatment Phase) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline to Week 24 (SB Treatment Period) in the Mean Daytime Somnolence Domain Score of the Medical Outcomes Study (MOS) Sleep Scale Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline to Week 24 (SB Treatment Period) in the Mean Sleep Disturbance Domain Score of the MOS Sleep Scale Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline to Week 24 (SB Treatment Period) in the Mean Sleep Adequacy Domain Score of the MOS Sleep Scale Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline in the MOS Sleep Scale Domain, Sleep Quantity, Score at Week 24 (SB Treatment Period) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Mean Change From Baseline in the Overall Quality of Life Impact Score of the RLS Quality of Life (QoL) Questionnaire at Week 24 (SB Treatment Phase)
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Overall Quality of Sleep in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Ability to Function in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Nights With RLS Symptoms in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Awakenings During the Night Due to RLS Symptoms in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Number of Participants With the Indicated Post-Sleep Questionnaire Responses to the Question Regarding the Number of Hours Awake Per Night Due to RLS Symptoms in the Week Prior to Measurement at Baseline and Week 24 (SB Treatment Period) Using LOCF
Time frame: Baseline and Day 168 or Week 24/End of Treatment of SB Treatment Phase
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Jul 2013.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 20511481Bogan RK, Bornemann MA, Kushida CA, Tran PV, Barrett RW; XP060 Study Group. Long-term maintenance treatment of restless legs syndrome with gabapentin enacarbil: a randomized controlled study. Mayo Clin Proc. 2010 Jun;85(6):512-21. doi: 10.4065/mcp.2009.0700.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
GSK Clinical Trials study director
GlaxoSmithKline
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing GEn (XP13512) in people with Restless Legs Syndrome, run by XenoPort, Inc..
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Jul 2013. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 25 May 2011). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of Participants Who Experienced a Relapse During the Double-Blind Treatment Period (time frame: DB Treatment Period; Days 169 to 252 (Weeks 24 to 36)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00311363, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Jul 2013.