Restless Legs SyndromePhase 3NCT00333359

XP13512 (Gabapentin Enacarbil) Extension Study in Patients With Restless Legs Syndrome.

A Phase 3 study testing XP13512 (GEn) in people with Restless Legs Syndrome, run by XenoPort, Inc..

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

The primary objective of this trial is to assess the long-term safety and efficacy of XP13512 (Gabapentin Enacarbil) taken once daily for the 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?: XP13512 (GEn)
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 581 participants
Where: No sites listed yet
Study dates: Jun 2006to Dec 2008
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 who have successfully completed one of the following studies: XP052 (110963 [NCT00298623]), XP053 (111460 [NCT00365352]), XP081 (111462 [NCT01332305]), and XP083 (111463 [NCT01332318]).

Who cannot join

Subjects who, in the opinion of the Investigator, would be non-compliant with the study visit schedule, procedures, or medication administration.

About this study

Official title: An Open-Label, 52-Week Extension Study Assessing XP13512 Safety and Efficacy in Patients With Restless Legs Syndrome.

Read the detailed description

Study XP055 is a multicenter, open-label, 52-week extension study of XP13512 (Gabapentin Enacarbil [GEn]) given once daily to eligible subjects with Restless Legs Syndrome (RLS) who had previously completed 1 of the following studies and met eligibility criteria: XP052 (110963 [NCT00298623]), XP053 (111460 [NCT00365352]), XP081 (111462 [NCT01332305]), and XP083 (111463 [NCT01332318]).

Conditions: Restless Legs Syndrome
Being tested: XP13512 (GEn)
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.

XP13512 (GEn)Drug
Also called GSK1838262, Gabapentin Enacarbil
1200 mg XP13512, orally, once daily for 52 weeks

Study groups in NCT00333359
Study group	Role	What they receive
XP13512 (GEn)	Experimental	1200 mg XP13512, orally, once daily for 52 weeks Receives: Drug: XP13512 (GEn)

What is being measured

The primary outcome is the main question the study is designed to answer.

Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC)
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.
Measured: Baseline and Week 52
Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC
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.
Measured: Weeks 0, 1, 4, 12, 24, 36, and 52

Secondary outcomes (10)

Change From Baseline in the IRLS Rating Scale Score at Each Visit Using OC
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.
Measured: Weeks 0, 1, 4, 12, 24, and 36
Number of Participants in Each Category of the Investigator-rated CGI-I by Visit Using OC
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.
Measured: Weeks 0, 1, and 52
Number of Participants Classified as Responders to Treatment on the Participant-rated CGI-I at Each Visit Using OC
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.
Measured: Weeks 0, 1, 4, 12, 24, 36, and 52
Number of Participants in Each Category of the Participant-rated CGI-I by Visit Using OC
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.
Measured: Weeks 0, 1, and 52
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
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).
Measured: Week 52
Median Time to Onset of the First RLS Symptom Using the RLS Symptom Record at 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.
Measured: Weeks 24 and 52
Overall Quality of Life (QoL) Impact Score of the RLS Quality of Life Questionnaire at 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.
Measured: Weeks 24 and 52
Mean Change From Baseline at Week 24 and Week 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Summary Scores
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.
Measured: Baseline and Weeks 24 and 52
Mean Change From Baseline at Week 24 and Week 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Individual Items: Hours of Work Missed Due to RLS, Hours of Work Missed Due to Other Reason, and Hours Actually Worked
The WPAI:SHP estimates work productivity and social activities lost over the past week due to RLS symptoms. Change is calculated as the observed value at Week 24/52 minus the observed value at baseline. Absenteeism is recorded as the number of hours missed from work. W, Week; hr, hour.
Measured: Baseline and Weeks 24 and 52
Mean Change From Baseline at Weeks 24 and 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Individual Item: RLS Affected Productivity
The WPAI:SHP estimates work productivity and social activities lost over the past week due to RLS symptoms. Change is calculated as the observed value at Week 52 minus the observed value at baseline. Productivity affected while working is estimated on a 0 (no effect) to 10 scale (completely preventing productivity).
Measured: Baseline and Weeks 24 and 52

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Jun 2006Dec 2008

First posted5 Jun 2006 (estimated)
Study startJun 2006
Primary completionDec 2008
Study completionDec 2008

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: Not applicable
Intervention model: Single group
Masking: None (open label)
Enrolment: 581 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT00333359
Sponsor's protocol ID: 111490
Status last verified: May 2011
First submitted: 1 Jun 2006
Last updated: 22 Jul 2013
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No

Publications

Ellenbogen AL, Thein SG, Winslow DH, Becker PM, Tolson JM, Lassauzet ML, Chen D. A 52-week study of gabapentin enacarbil in restless legs syndrome. Clin Neuropharmacol. 2011 Jan-Feb;34(1):8-16. doi: 10.1097/WNF.0b013e3182087d48.
PubMed 21242741

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

Official record

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All Restless Legs Syndrome trials

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: An Open-Label, 52-Week Extension Study Assessing XP13512 Safety and Efficacy in Patients With Restless Legs Syndrome.
ClinicalTrials.gov ID: NCT00333359
Acronym / sponsor ID: 111490
Conditions: Restless Legs Syndrome
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 581 participants (actual)
Lead sponsor: XenoPort, Inc.Industry (pharma, biotech, devices)
Study start: Jun 2006
Primary completion: Dec 2008 (actual)
Study completion: Dec 2008 (actual)
First posted: 5 Jun 2006 (estimated)
Results: Posted 23 Jun 2011

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1

Arm	Type	Receives
XP13512 (GEn)	Experimental	Drug: XP13512 (GEn)1200 mg XP13512, orally, once daily for 52 weeks

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 who have successfully completed one of the following studies: XP052 (110963 [NCT00298623]), XP053 (111460 [NCT00365352]), XP081 (111462 [NCT01332305]), and XP083 (111463 [NCT01332318]).

Key exclusion criteria (1 listed)

Subjects who, in the opinion of the Investigator, would be non-compliant with the study visit schedule, procedures, or medication administration.

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
XP13512 (GEn)Also: GSK1838262, Gabapentin Enacarbil1200 mg XP13512, orally, once daily for 52 weeks	Drug	XP13512 (GEn)

Primary outcome

Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC)
Time frame: 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.
Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC
Time frame: 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.

10 secondary outcomes

Change From Baseline in the IRLS Rating Scale Score at Each Visit Using OC
Time frame: Weeks 0, 1, 4, 12, 24, and 36
Number of Participants in Each Category of the Investigator-rated CGI-I by Visit Using OC
Time frame: Weeks 0, 1, and 52
Number of Participants Classified as Responders to Treatment on the Participant-rated CGI-I at Each Visit Using OC
Time frame: Weeks 0, 1, 4, 12, 24, 36, and 52
Number of Participants in Each Category of the Participant-rated CGI-I by Visit Using OC
Time frame: Weeks 0, 1, and 52
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
Time frame: Week 52
Median Time to Onset of the First RLS Symptom Using the RLS Symptom Record at Weeks 24 and 52
Time frame: Weeks 24 and 52
Overall Quality of Life (QoL) Impact Score of the RLS Quality of Life Questionnaire at Weeks 24 and 52
Time frame: Weeks 24 and 52
Mean Change From Baseline at Week 24 and Week 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Summary Scores
Time frame: Baseline and Weeks 24 and 52
Mean Change From Baseline at Week 24 and Week 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Individual Items: Hours of Work Missed Due to RLS, Hours of Work Missed Due to Other Reason, and Hours Actually Worked
Time frame: Baseline and Weeks 24 and 52
Mean Change From Baseline at Weeks 24 and 52 in Work Productivity and Activity Impairment Questionnaire (WPAI:SHP) Individual Item: RLS Affected Productivity
Time frame: Baseline and Weeks 24 and 52

Results and safety

Results posted to the registry on 23 Jun 2011, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Naïve; 1200 mg GEn	199	126
Non-naïve; 1200 mg GEn	382	260

Primary outcome: Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC)

Time frame: Baseline and Week 52. Mean (Standard Deviation). Unit: points on a scale

Measure	Naïve; 1200 mg GEn n = 125	Non-naïve; 1200 mg GEn n = 254	All Participants; 1200 mg GEn n = 379
Value	-16.3 (8.23)	-17.0 (8.20)	-16.8 (8.21)

Population analysed: 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.

Primary outcome: Number of Participants Classified as Responders to Treatment on the Investigator-rated Clinical Global Impressions of Improvement (CGI-I) at Each Visit Using OC

Time frame: Weeks 0, 1, 4, 12, 24, 36, and 52. Number. Unit: participants

Measure	Naïve; 1200 mg GEn n = 197	Non-naïve; 1200 mg GEn n = 376	All Participants; 1200 mg GEn n = 573
Week 0, n=197, 376, 573	84	300	384
Week 1, n=185, 363, 548	152	294	446
Week 4, n=171, 354, 525	143	308	451
Week 12, n=150, 324, 474	133	297	430
Week 24, n=138, 305, 443	126	275	401
Week 36, n=132, 281, 413	120	260	380
Week 52, n=126, 262, 388	115	247	362

Population analysed: 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.

10 secondary outcomes are reported in the full results.

Adverse events

Time frame: Adverse event (AE) and serious adverse event (SAE) collection started immediately following informed consent and continued throughout the study (up to Week 53).. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Naïve; 1200 mg GEn	7 of 197 (3.6%)	114 of 197 (57.9%)	Not reported
Non-naïve; 1200 mg GEn	14 of 376 (3.7%)	144 of 376 (38.3%)	Not reported
All Participants; 1200 mg GEn	21 of 573 (3.7%)	258 of 573 (45%)	Not reported

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 21242741Ellenbogen AL, Thein SG, Winslow DH, Becker PM, Tolson JM, Lassauzet ML, Chen D. A 52-week study of gabapentin enacarbil in restless legs syndrome. Clin Neuropharmacol. 2011 Jan-Feb;34(1):8-16. doi: 10.1097/WNF.0b013e3182087d48.

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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 XP13512 (GEn) 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 1 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. 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 23 Jun 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?

Change From Baseline in the International Restless Legs Syndrome Rating Scale (IRLS) at Week 52 Using Observed Case (OC) (time frame: Baseline and Week 52). The study lists 2 primary outcomes in all. 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 NCT00333359, 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.