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XP13512 (GSK1838262) Versus Placebo in Patients With Restless Legs Syndrome.

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: March 2, 2006
Last Update Posted: May 14, 2013
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
XenoPort, Inc.
The primary objective of this trial is to assess the efficacy of XP13512 taken once daily compared to placebo for the treatment of patients suffering from Restless Legs Syndrome (RLS).

Condition Intervention Phase
Restless Legs Syndrome Drug: XP13512 (GSK1838262) Other: placebo Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: A Randomized, Double-Blind, Placebo-Controlled Study to Assess the Efficacy and Safety of XP13512 in Patients With Restless Legs Syndrome.

Resource links provided by NLM:

Further study details as provided by XenoPort, Inc.:

Primary Outcome Measures:
  • The change from baseline to the end of treatment in International Restless Legs Syndrome (IRLS) rating scale score. [ Time Frame: 12-week treatment period ]
  • The proportion of subjects at the end of treatment who are "much improved" or "very much improved" on the Investigator-rated CGI of Improvement [ Time Frame: 12-week treatment period ]

Secondary Outcome Measures:
  • Onset of efficacy. Subjective measures of sleep. [ Time Frame: 12-week treatment period ]

Enrollment: 222
Study Start Date: March 2006
Study Completion Date: February 2007
Primary Completion Date: February 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo Other: placebo
Experimental: XP13512 (GSK1838262) Drug: XP13512 (GSK1838262)


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients with primary RLS, based on the International RLS Study Group Diagnostic Criteria.
  • History of RLS symptoms at least 15 nights in the prior month or, if on treatment, this frequency of symptoms before treatment was started;
  • Documented RLS symptoms for at least 4 of the 7 consecutive evenings/nights during the Baseline study period;
  • Total RLS severity score of 15 or greater on the International Restless Legs Syndrome Study Group Rating Scale (IRLS rating scale) at Visit 1 and at Visit 2;
  • Discontinuation of dopamine agonists and/or gabapentin at least 2 weeks prior to Baseline;
  • Discontinuation of other treatments for RLS (e.g., opioids, benzodiazepines) at least 2 weeks prior to Baseline;
  • If female of child-bearing potential, the subject must agree to use clinically accepted birth control through completion of the study;
  • Body Mass Index of 34 or below;
  • Estimated creatinine clearance of at least 60 mL/min;

Exclusion Criteria:

  • 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.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00298623

Sponsors and Collaborators
XenoPort, Inc.
Study Director: GSK Clinical Trials GlaxoSmithKline
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Cheri Hudson; Clinical Disclosure Advisor, GSK Clinical Disclosure
ClinicalTrials.gov Identifier: NCT00298623     History of Changes
Other Study ID Numbers: 110963
First Submitted: February 28, 2006
First Posted: March 2, 2006
Last Update Posted: May 14, 2013
Last Verified: May 2011

Additional relevant MeSH terms:
Psychomotor Agitation
Restless Legs Syndrome
Pathologic Processes
Neurologic Manifestations
Nervous System Diseases
Psychomotor Disorders
Neurobehavioral Manifestations
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Mental Disorders