Restless Legs SyndromePhase 2XP083NCT01332318

Simulated Driving Study in Restless Legs Syndrome

A Phase 2 study testing XP13512 and Diphenhydramine in people with Restless Legs Syndrome, run by XenoPort, Inc. at 1 site in United States.

Completed

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

Official record

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Trial summary

Who is it for?: Ages 21 to 65 years
Conditions the study is for: Restless Legs Syndrome
What is being tested?: XP13512 and Diphenhydramine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 130 participants
Where: 1 siteUnited States
Study dates: Apr 2007to Nov 2007
Phase: Phase 2
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 21 to 65 years
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Men or women who were 21 through 65 years of age and fluent in English;
Subjects with RLS, based on the IRLSSG Diagnostic Criteria;
Currently a licensed and experienced driver who has driven an average of 3 or more times/week for the past 3 years;
Able to successfully complete the 5 minute practice simulated driving test at Screening;
History of RLS symptoms at least 15 nights in the prior month or, if on treatment, this frequency of symptoms before treatment was started;
Total RLS severity score of 15 or greater on the IRLS Rating Scale;

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Documented RLS symptoms for at least 4 of the 7 consecutive evenings/nights Discontinuation of treatments for RLS (e.g., opioids, benzodiazepines, dopamine agonists and/or gabapentin) at least 2 weeks prior to Screening; -
Body Mass Index of 34 or below;
Estimated creatinine clearance of at least 60 mL/min;
Agreed to maintain abstinence from alcohol and smoking throughout the entire study period;
Agreed to maintain abstinence from caffeine from midnight of the day prior to and until the end of each Visit (Visits 2 to 4).

Who cannot join

A sleep disorder (e.g., sleep apnea) other than RLS that may significantly affect the assessment of RLS;
Current use of a sleeping medication or sedating medication;
Current use of CNS stimulants;
Neurologic disease or movement disorder;
Other medical conditions which could affect RLS assessments;
Significant medical history that may impair psychomotor coordination;

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Subjects who had clinically significant or unstable medical conditions;
Serum ferritin level below 20 ng/mL;
Subjects currently suffering from moderate or severe depression using the Diagnostic and Statistical Manual of Mental Disorders and Treatment IV (DSM IV TR);
Subjects with a history of substance abuse (alcohol or drugs) or substance dependence within 12 months prior to enrollment;
Shift workers or subjects who were not on normal day/night sleep cycles;
Subjects who had smoked an average of greater than one half pack of cigarettes (or nicotine equivalent) per day within 30 days of the Screening Visit;
Subjects who had consumed an average of >5 cups (i.e., 40 ounces) of caffeinated beverages per day within 20 days of the Screening Visit;
Subjects with a history of allergy to gabapentin, diphenhydramine, or XP13512 excipients

Trial locations and contacts

1 site in 1 country.

United States1 site

GSK Investigational Site
Albuquerque, New Mexico, 87108

Other trials in United States

About this study

Official title: A Randomized, Double Blind, Active- and Placebo-Controlled, Parallel Group Safety Study Assessing Simulated Driving Performance in XP13512-(GSK1838262) Treated Patients With Restless Legs Syndrome

This study was a multi center, randomized, double blind, active and placebo controlled, parallel group study to assess simulated driving performance in XP13512 treated subjects with Restless Legs Syndrome (RLS). Eligible subjects were randomized to receive a once daily dose of placebo (2 groups), XP13512 1200 mg, or XP13512 1800 mg for 16 days. On Day 16, one of the placebo groups also received one 50 mg dose of diphenhydramine (DPH) to assess the effects of an agent known to have sedative properties, while the other 3 groups received a DPH placebo.

Read the detailed description

This study was a multicenter, randomized, double blind, active and placebo controlled, parallel group study. Eligible subjects were randomized in a 1:1:1:1 ratio to 1 of the following 4 treatment groups:

XP13512 Placebo + Diphenhydramine Placebo (Pbo) B) XP13512 1200 mg/day + Diphenhydramine Placebo (1200 mg) C) XP13512 1800 mg/day + Diphenhydramine Placebo (1800 mg) D) XP13512 Placebo + 50 mg Diphenhydramine (Pbo/DPH)

Conditions: Restless Legs Syndrome
Being tested: XP13512, Diphenhydramine, 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.

XP13512Drug
Also called GSK1838262, Gabapentin Enacarbil (GEn)
XP13512 once daily for 16 days
DiphenhydramineDrug
one 50 mg dose of diphenhydramine (DPH) on day 16
PlaceboDrug
XP13512 placebo once daily for 16 days

Study groups in NCT01332318
Study group	Role	What they receive
Placebo	Placebo comparator	XP13512 Placebo + Diphenhydramine Placebo Receives: Drug: Placebo
XP13512 1200 mg	Experimental	XP13512 1200 mg/day + Diphenhydramine Placebo Receives: Drug: XP13512
XP13512 1800 mg	Experimental	XP13512 1800 mg/day + Diphenhydramine Placebo Receives: Drug: XP13512
Placebo + Diphenhydramine	Active comparator	XP13512 Placebo + 50 mg Diphenhydramine Receives: Drug: Diphenhydramine; Drug: Placebo

What is being measured

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

Change From Baseline (Day -1) in Overall Lane Position Variability (LPV) on Day 16 (Tmax)
Lane position variability (LPV) was defined as the standard deviation of lane position, and was measured from the center line of the 26 foot wide 2-lane paved road to the center of the vehicle. Change from baseline in overall LPV was calculated as the Day 16 mean LPV over the 1-hour drive minus the Baseline mean LPV over the 1-hour drive. The Day 16 measurement is at the time of maximum concentration (Tmax) for both GEn and DPH.
Measured: Baseline (Day -1) and Day 16

Secondary outcomes (27)

Change From Baseline (Day -1) to Day 14 (Evening) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Lane Position Variability (LPV)
Lane position variability (LPV) was defined as the standard deviation of lane position, and was measured from the center line of the 26 foot wide 2-lane paved road to the center of the vehicle. Change from baseline in overall LPV was calculated as the Day 14 (in the evening) or Day 15 (in the morning after GEn dosed at 5 PM) mean LPV over the 1-hour drive minus the Baseline (Day -1 or Day 1) mean LPV over the 1-hour drive.
Measured: Baseline (Days -1 and 1) and Days 14 and 15
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Average Lane Position
Lane position was measured from the center line of the 26 foot wide 2-lane paved road to the center of the vehicle. Change from baseline in overall average lane position was calculated as the Day 14 (in the evening), 15 (in the morning after GEn dosed at 5 PM), or 16 (assessment at Tmax of GEn and DPH) mean lane position over the 1-hour drive minus the Baseline (Days -1 and 1) mean lane position over the 1-hour drive.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Speed Variability
Speed variability was defined as the standard deviation of the speed (measured in miles per hour). Participants were instructed to maintain a speed of 55 miles per hour during the test drive. Change from baseline in overall speed variability was calculated as the Day 14 (in the evening), 15 (in the morning), or 16 (at Tmax of GEn and DPH) mean speed variability over the 1-hour drive minus the Baseline (Days -1 and 1) mean speed variability over the 1-hour drive.
Measured: Baseline (Day -1) and Days 14 and 16; baseline (Day 1) and Day 15
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Average Speed
Participants were instructed to maintain a speed of 55 miles per hour during the driving assessment. Change from baseline in overall average speed was calculated as the Day 14 (in the evening), 15 (in the morning), or 16 (at Tmax of GEn and DPH) mean speed over the 1-hour drive minus the Baseline (Days -1 and 1) mean speed over the 1-hour drive.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Number of Participants With the Indicated Number of Simulated Crashes on Days 14 (Evening), 15 (Morning After Dose), and 16 (Tmax)
A simulated crash was defined as a collision with an oncoming car or obstacle (e.g., tree) or when the distance to the center line was greater than 18 feet on either side of the road.
Measured: Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Brake Reaction Time
Brake reaction time was assessed as the time it took for each participant to move their foot off the accelerator and onto the brake pedal after the appearance of a stop sign on the simulation screen. Change from baseline was calculated as the Day 14, 15, or 16 mean reaction time minus the Baseline (Days -1 and 1) mean reaction time.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in the Alertness Visual Analog Scale (VAS) Score
Alertness VAS was completed immediately before and after each simulated driving assessment. Participants indicated their alertness by marking a vertical line on a horizontal scale anchored by responses "extremely sleepy" and "extremely alert." VAS score was determined by measuring the distance in millimeters (mm) from the left hand end of the line to the point the participant marked. Scores ranged from 0-100 mm, with higher scores indicating more alertness and lower scores indicating more sleepiness. Change score was calculated as the Day 14, 15, or 16 VAS score minus the Baseline VAS score.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) in the Epworth Sleepiness Scale (ESS) Total Score
The Epworth Sleepiness Scale (ESS) is a questionnaire designed to evaluate daytime sleepiness. Participants were asked to rate how likely they were to doze or fall asleep during 8 activities on a scale of 0 ("would never do") to 3 ("high chance of dozing"). The total score ranges from 0-24, with a score greater than 10 representing excessive daytime sleepiness (an increased chance of dozing). Change from baseline was calculated as the Day 14 total score minus the Baseline total score.
Measured: Baseline (Day -1) and Day 14
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Composite Score
The BAC was designed as a comprehensive measure of cognitive function, including 6 individual tests: Verbal Memory Recall, Digit Sequencing, Token Motor Task, Verbal Fluency, Symbol Coding, and Tower of London. The composite/total BAC score is calculated by scoring each individual test, comparing each score to a healthy control sample (matched for sex and age category) to create z-scores, summing the z-scores, and rescaling the sum. The composite score range is -2127.8 to 1878.8, with higher scores indicating better cognition.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Verbal Memory Test Score
Participants were presented with 15 words and asked to recall as many as possible; the procedure was repeated 5 times. The total number of words recalled correctly across the 5 administrations of the list was the participant's Verbal Memory Recall score (range: 0-75). The scaled test score was calculated as ((BAC component raw test score - healthy control sample test mean)/healthy control sample test standard deviation); a healthy control sample was matched to the participant's sex and age category. The scaled test score range is -7.37 to 4.86; higher scaled scores indicate better cognition.
Measured: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Digit Sequencing Score (DSS)
Participants (par.) were presented with sets of numbers of increasing length and asked to tell the experimenter the numbers in order from lowest to highest. The task has 7 levels; the first level had 2 digits in the set (e.g., 5, 2); the second level had 3 digits in the set, etc. The number of times the par. correctly arranged the numbers was recorded as the score for each level. The DSS is the sum of the 7 level scores (range: 0-28). The scaled test score was calculated as indicated for the Verbal Memory Test and ranges from -6.68 to 2.73; higher scaled scores indicate better cognition.
Measured: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Token Motor Task Test Score
Participants were given 100 plastic tokens and asked to place them in a container, 2 at a time, as quickly as possible for 60 seconds. The number of tokens correctly placed in the container was the Token Motor Task score (range: 0-100). The BAC was conducted prior to each simulated driving test. The Token Motor Task scaled test score was calculated as indicated for the Verbal Memory Test. Change from baseline was calculated as the Day composite score minus the Baseline composite score. The scaled test score range is -6.95 to 3.35, with higher scaled scores indicating better cognition.
Measured: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Verbal Fluency Test Score
Verbal Fluency included one semantic fluency and two letter fluency tasks. Participants were given 60 seconds to name as many words as possible within a given semantic category (supermarket items), and in two separate trials, participants were given 60 seconds to generate as many words as possible that began with a given letter. The total number of words from all of the 3 trials was the Verbal Fluency score (range: 0-150). The scaled test score was calculated as indicated for the Verbal Memory Test. The scaled test score range is -5 to 10.83; higher scaled scores indicate better cognition.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Symbol Coding Test Score
Participants were given a list of numbers (numerals 1-9) that were each associated with a unique symbol. Participants decoded a list of 110 symbols as quickly as possible in 90 seconds. The total number of symbols correctly decoded was the Symbol Coding Score (range: 0-110). The Symbol Coding scaled test score was calculated as indicated for the Verbal Memory Test. Change from baseline was calculated as the Day composite score minus the Baseline composite score. The scaled test score range is -7 to 10.08, with higher scaled scores indicating better cognition.
Measured: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Tower of London (TOL) Score
Participants (par.) were asked to look at 2 pictures simultaneously; each picture showed 3 different colored balls arranged on 3 pegs. Par. were to estimate the number of times the balls in 1 picture would have to be moved to make the arrangement of balls identical to that of the second picture. Par. were allowed 20 seconds to respond to each pair of pictures. The number of correct items was the TOL Score (range: 0-22). The TOL scaled test score was calculated as indicated for the Verbal Memory Test. The scaled test score range is -7.53 to 2.76; higher scaled scores indicate better cognition.
Measured: Baseline (Days -1and 1) and Days 14, 15, and 16
Mean Change From Baseline (Day -1) at Day 14 in the International Restless Legs Syndrome (IRLS) Rating Scale Total Score
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.
Measured: Baseline (Day -1) and Day 14
Number of Participants in Each Category of the Investigator-Rated Clinician Global Impression of Improvement (CGI-I) Scale at Day 14
The CGI scale is a widely used tool designed to allow clinicians to rate the severity of illness and the change of the 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: Day 14
Number of Participants Who Responded to Treatment Based on Scores on the Investigator-Rated CGI-I at Day 14
The investigator-rated CGI-I is a clinician-rated assessment designed to allow clinicians to rate the change of their participant's 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. For this endpoint, "response" was defined as a rating of "very much improved" or "much improved" (score of 1 or 2 on the scale) compared to baseline.
Measured: Day 14
Number of Participants in Each Category of the Participant-Rated Clinician Global Impression of Improvement (CGI-I) Scale at Day 14
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".
Measured: Day 14
Number of Participants Who Responded to Treatment Based on Scores on the Participant-Rated CGI-I at Day 14
The participant-rated CGI-I 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" was defined as a rating of "very much improved" or "much improved" (score of 1 or 2 on the scale).
Measured: Day 14
Median Time to Onset of a Participant's First RLS Symptoms Using the 24-hour RLS Symptom Record at Day 14
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. For Arms 2 and 3, upper limits of the confidence intervals are not available, as they are beyond the 24-hour time frame.
Measured: Day 14
Percentage of Participants With no Reported RLS Symptoms During the 24-hour RLS Record at Day 14
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.
Measured: Day 14
Number of Participants With no Reported RLS Symptoms During Each of the 4-hour Periods From the 24-hour RLS Record at Day 14
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-minute increments. The period was divided into 7 four-hour intervals (8 AM to 12 PM, 12 PM to 4 PM, 4 PM to 8 PM, 6 PM to 10 PM, 8 PM to 12 Midnight, Midnight to 4 AM, and 4 AM to 8 AM).
Measured: Day 14
Number of Participants With the Indicated Post Sleep Questionnaire (PSQ) Responses at Day 14
The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep.
Measured: Day 14
Mean Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Pittsburgh Sleep Diary (PghSD) Sleep Onset Items
The PghSD assessed participant's previous night's sleep. Change from baseline was calculated as the Day 14 (in the evening), 15 (in the morning), and 16 (at Tmax of GEn and DPH) value minus the Baseline (Days -1 and 1) value. Latency to sleep onset (time to fall asleep) and wake time after sleep onset are expressed in minutes.
Measured: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in the Pittsburgh Sleep Diary (PghSD) Total Sleep Time Item
The PghSD assessed a participant's previous night's sleep. Change from baseline was calculated as the Day 14 (in the evening), 15 (in the morning after dose), and 16 (at Tmax)value minus the Baseline (Days -1 and 1) value. Total sleep time is expressed in hours.
Measured: Baseline (Days -1 and 1) and Days 14, 15, and 16
Mean Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in the Pittsburgh Sleep Diary (PghSD) Sleep Quality
The PghSD assessed a participant's previous night's sleep. Sleep quality was assessed using a Visual Analogue Scale (VAS). Participants indicated their sleep quality by marking a vertical line on a horizontal scale anchored by responses "very bad" and "very good." VAS score was determined by measuring the distance in millimeters (mm) from the left hand end of the line to the point that the participant marked. Scores ranged from 0 to 100 mm with higher scores indicating better sleep quality and lower scores indicating worse sleep quality.
Measured: Baseline (Day -1and 1) and Days 14, 15, and 16

Timeline

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

Apr 2007Nov 2007

First posted11 Apr 2011 (estimated)
Study startApr 2007
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.
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 2
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind
Who is masked: Participant, Investigator
Enrolment: 130 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT01332318
Sponsor's protocol ID: 111463
Other IDs: XP083
Acronym: XP083
Status last verified: Jun 2011
First submitted: 7 Apr 2011
Last updated: 26 Jul 2013
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes

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?

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Study at a glance

From the registry record, last updated by the sponsor on 26 Jul 2013. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Randomized, Double Blind, Active- and Placebo-Controlled, Parallel Group Safety Study Assessing Simulated Driving Performance in XP13512-(GSK1838262) Treated Patients With Restless Legs Syndrome
ClinicalTrials.gov ID: NCT01332318
Acronym / sponsor ID: XP083 / 111463
Conditions: Restless Legs Syndrome
Phase: Phase 2
Study type: Interventional
Recruitment status: Completed
Enrolment: 130 participants (actual)
Lead sponsor: XenoPort, Inc.Industry (pharma, biotech, devices)
Study start: Apr 2007
Primary completion: Nov 2007 (actual)
Study completion: Nov 2007 (actual)
First posted: 11 Apr 2011 (estimated)
Results: Posted 28 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

XP13512 Placebo + Diphenhydramine Placebo (Pbo) B) XP13512 1200 mg/day + Diphenhydramine Placebo (1200 mg) C) XP13512 1800 mg/day + Diphenhydramine Placebo (1800 mg) D) XP13512 Placebo + 50 mg Diphenhydramine (Pbo/DPH)

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind (participant, investigator)
Number of arms: 4

Arm	Type	Receives
Placebo	Placebo comparator	Drug: PlaceboXP13512 Placebo + Diphenhydramine Placebo
XP13512 1200 mg	Experimental	Drug: XP13512XP13512 1200 mg/day + Diphenhydramine Placebo
XP13512 1800 mg	Experimental	Drug: XP13512XP13512 1800 mg/day + Diphenhydramine Placebo
Placebo + Diphenhydramine	Active comparator	Drug: Diphenhydramine, Drug: PlaceboXP13512 Placebo + 50 mg Diphenhydramine

Who may qualify

Ages: 21 to 65 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (11 listed)

Men or women who were 21 through 65 years of age and fluent in English;
Subjects with RLS, based on the IRLSSG Diagnostic Criteria;
Currently a licensed and experienced driver who has driven an average of 3 or more times/week for the past 3 years;
Able to successfully complete the 5 minute practice simulated driving test at Screening;
History of RLS symptoms at least 15 nights in the prior month or, if on treatment, this frequency of symptoms before treatment was started;

Key exclusion criteria (14 listed)

A sleep disorder (e.g., sleep apnea) other than RLS that may significantly affect the assessment of RLS;
Current use of a sleeping medication or sedating medication;
Current use of CNS stimulants;
Neurologic disease or movement disorder;
Other medical conditions which could affect RLS assessments;

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
XP13512Also: GSK1838262, Gabapentin Enacarbil (GEn)XP13512 once daily for 16 days	Drug	XP13512 1200 mg, XP13512 1800 mg
Diphenhydramineone 50 mg dose of diphenhydramine (DPH) on day 16	Drug	Placebo + Diphenhydramine
PlaceboXP13512 placebo once daily for 16 days	Drug	Placebo, Placebo + Diphenhydramine

Primary outcome

Change From Baseline (Day -1) in Overall Lane Position Variability (LPV) on Day 16 (Tmax)
Time frame: Baseline (Day -1) and Day 16
Lane position variability (LPV) was defined as the standard deviation of lane position, and was measured from the center line of the 26 foot wide 2-lane paved road to the center of the vehicle. Change from baseline in overall LPV was calculated as the Day 16 mean LPV over the 1-hour drive minus the Baseline mean LPV over the 1-hour drive. The Day 16 measurement is at the time of maximum concentration (Tmax) for both GEn and DPH.

27 secondary outcomes

Change From Baseline (Day -1) to Day 14 (Evening) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Lane Position Variability (LPV)
Time frame: Baseline (Days -1 and 1) and Days 14 and 15
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Average Lane Position
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Speed Variability
Time frame: Baseline (Day -1) and Days 14 and 16; baseline (Day 1) and Day 15
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Overall Average Speed
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Number of Participants With the Indicated Number of Simulated Crashes on Days 14 (Evening), 15 (Morning After Dose), and 16 (Tmax)
Time frame: Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in Brake Reaction Time
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in the Alertness Visual Analog Scale (VAS) Score
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) in the Epworth Sleepiness Scale (ESS) Total Score
Time frame: Baseline (Day -1) and Day 14
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Composite Score
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Verbal Memory Test Score
Time frame: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Digit Sequencing Score (DSS)
Time frame: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Token Motor Task Test Score
Time frame: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Verbal Fluency Test Score
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Symbol Coding Test Score
Time frame: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Brief Assessment of Cognition (BAC) Scaled Tower of London (TOL) Score
Time frame: Baseline (Days -1and 1) and Days 14, 15, and 16
Mean Change From Baseline (Day -1) at Day 14 in the International Restless Legs Syndrome (IRLS) Rating Scale Total Score
Time frame: Baseline (Day -1) and Day 14
Number of Participants in Each Category of the Investigator-Rated Clinician Global Impression of Improvement (CGI-I) Scale at Day 14
Time frame: Day 14
Number of Participants Who Responded to Treatment Based on Scores on the Investigator-Rated CGI-I at Day 14
Time frame: Day 14
Number of Participants in Each Category of the Participant-Rated Clinician Global Impression of Improvement (CGI-I) Scale at Day 14
Time frame: Day 14
Number of Participants Who Responded to Treatment Based on Scores on the Participant-Rated CGI-I at Day 14
Time frame: Day 14
Median Time to Onset of a Participant's First RLS Symptoms Using the 24-hour RLS Symptom Record at Day 14
Time frame: Day 14
Percentage of Participants With no Reported RLS Symptoms During the 24-hour RLS Record at Day 14
Time frame: Day 14
Number of Participants With no Reported RLS Symptoms During Each of the 4-hour Periods From the 24-hour RLS Record at Day 14
Time frame: Day 14
Number of Participants With the Indicated Post Sleep Questionnaire (PSQ) Responses at Day 14
Time frame: Day 14
Mean Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) on the Pittsburgh Sleep Diary (PghSD) Sleep Onset Items
Time frame: Baseline (Days -1and 1) and Days 14, 15, and 16
Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in the Pittsburgh Sleep Diary (PghSD) Total Sleep Time Item
Time frame: Baseline (Days -1 and 1) and Days 14, 15, and 16
Mean Change From Baseline (Day -1) to Day 14 (Evening) and Day 16 (at Tmax) and Change From Baseline (Day 1) to Day 15 (Morning After Dose) in the Pittsburgh Sleep Diary (PghSD) Sleep Quality
Time frame: Baseline (Day -1and 1) and Days 14, 15, and 16

Results and safety

Results posted to the registry on 28 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
GEn Placebo and DPH Placebo	34	32
GEn 1200 mg and DPH Placebo	32	28
GEn 1800 mg and DPH Placebo	34	33
GEn Placebo and DPH 50 mg on Day 16	30	28

Primary outcome: Change From Baseline (Day -1) in Overall Lane Position Variability (LPV) on Day 16 (Tmax)

Time frame: Baseline (Day -1) and Day 16. Least squares mean (Standard Error). Unit: feet

Measure	GEn Placebo and DPH Placebo n = 30	GEn 1200 mg and DPH Placebo n = 28	GEn 1800 mg and DPH Placebo n = 33	GEn Placebo and DPH 50 mg on Day 16 n = 28
Value	-0.10 (0.06)	0.15 (0.06)	0.15 (0.06)	0.16 (0.06)

GEn Placebo and DPH Placebo vs GEn 1200 mg and DPH Placebo: Least Squares Mean Difference: 0.15 (95% CI 0.08 to 0.42)
GEn Placebo and DPH Placebo vs GEn 1800 mg and DPH Placebo: Least Squares Mean Difference: 0.15 (95% CI 0.09 to 0.41)
GEn Placebo and DPH Placebo vs GEn Placebo and DPH 50 mg on Day 16: Least Squares Mean Difference: 0.16 (95% CI 0.09 to 0.42)

Population analysed: Modified Intent-to-Treat (MITT) Population: all participants in the Safety Population who completed at least one Baseline and one End of Study (Days 14-16) simulated driving assessment. The number of participants assessed at each study day varies due to incomplete/missing data.

27 secondary outcomes are reported in the full results.

Adverse events

Time frame: Treatment-Emergent Adverse Events (TEAEs): First dose of randomized study medication through end of Taper Phase (Day 23). Any Serious Adverse Event (SAE) reported up to 30 days after last dose was also reported.. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
GEn Placebo and DPH Placebo	0 of 34 (0%)	10 of 34 (29.4%)	Not reported
GEn 1200 mg and DPH Placebo	0 of 31 (0%)	16 of 31 (51.6%)	Not reported
GEn 1800 mg and DPH Placebo	0 of 34 (0%)	21 of 34 (61.8%)	Not reported
GEn Placebo and DPH 50 mg on Day 16	0 of 30 (0%)	11 of 30 (36.7%)	Not reported

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 26 Jul 2013.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

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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

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing XP13512 and Diphenhydramine in people with Restless Legs Syndrome, run by XenoPort, Inc. at 1 site in United States.

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 11 inclusion and 14 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 26 Jul 2013. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

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 28 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 (Day -1) in Overall Lane Position Variability (LPV) on Day 16 (Tmax) (time frame: Baseline (Day -1) and Day 16). 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 NCT01332318.

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 26 Jul 2013.