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

This study has been completed.
Information provided by:
XenoPort, Inc. Identifier:
First received: February 28, 2006
Last updated: May 10, 2013
Last verified: May 2011
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)


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
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Please refer to this study by its identifier: NCT00298623

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

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Cheri Hudson; Clinical Disclosure Advisor, GSK Clinical Disclosure Identifier: NCT00298623     History of Changes
Other Study ID Numbers: 110963
Study First Received: February 28, 2006
Last Updated: May 10, 2013

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 processed this record on August 17, 2017