Phase 4
N=501
Gabapentin Enacarbil (GSK1838262) Adult Restless Leg Syndrome (RLS) Post Marketing Commitment Study
Restless Legs Syndrome
Bottom Line
View on ClinicalTrials.gov: NCT01668667 ↗Enrolled (actual)
501
Serious AEs
0.8%
Results posted
Nov 2014
Primary outcome: Primary: The Change From Baseline to the End of Treatment in the International Restless Legs Syndrome (IRLS) Rating Scale Score — -12.50; -12.54; -11.48; -9.93 units on a scale — p=0.014
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 4
- Interventions
- GSK1838262 600 mg (Drug); GSK1838262 450 mg (Drug); GSK1838262 300 mg (Drug); GSK1838262 Placebo match (Drug)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- XenoPort, Inc.
- Primary completion
- Nov 2013
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY The Change From Baseline to the End of Treatment in the International Restless Legs Syndrome (IRLS) Rating Scale Score |
-12.50; -12.54; -11.48; -9.93 | 0.014 sig |
| PRIMARY The Proportion of Subjects at the End of Treatment Who Are Responders With Either "Much Improved" or "Very Much Improved" on the Investigator-rated Clinical Global Impression of Improvement (CGI-I) |
67; 67; 68; 50 | 0.004 sig |
| SECONDARY The Dose-response Relationship of Change From Baseline in IRLS Rating Scale Total Score at End of Treatment |
-12.1; -12.7; -11.3; -9.8 | 0.022 sig |
| SECONDARY The Dose-response Relationship for Investigator-rated CGI-I Scale at End of Treatment |
67; 67; 68; 50; 33; 33 | 0.012 sig |
Summary
Gabapentin enacarbil (GEn; GSK1838262; HORIZANT), at a dose of 600 mg/day, is currently approved in the United States for the treatment of adults with moderate-to-severe primary Restless Legs Syndrome (RLS). The aim of this study is to compare the efficacy, tolerability, and safety of GEn at lower doses (450 and 300 mg/day) as well as the already approved dose of 600 mg/day versus placebo for the treatment of subjects with moderate to severe primary RLS. This study is being conducted as a post-marketing commitment (PMC) as a condition of the approval of HORIZANT tablets (NDA 022399).
Eligibility Criteria
Inclusion Criteria
- Men or women 18 years of age or older
- History of RLS symptoms for at least 15 nights/month
- Documented RLS symptoms, using the 7-day RLS Symptom Record, for at least 4 of the 7 consecutive evenings/nights during the night
- Total RLS severity score of 15 or greater on the International RLS (IRLS) Rating Scale at Visit 1 and at Visit 2
- Discontinuation of dopamine agonists and/or gabapentin , or other treatments for RLS (e.g. opioids, benzodiazepines) at least 2 weeks prior to Baseline
- If taking any prescription medication, therapy must have been stabilized for at least 3 months prior to Screening with no anticipated changes for the duration of the study
- Female subjects are eligible if of non-childbearing potential or not lactating, has a negative pregnancy, and agrees to use a highly effective method for avoiding pregnancy
- Body mass index of 34 or below
- Estimated creatinine clearance of ≥60 mL/min
- Provides written consent in accordance with all applicable regulatory requirements
Exclusion Criteria
- History of a sleep disorder that may affect the assessment of RLS
- History of RLS symptom augmentation or end-of-dose rebound with previous dopamine agonist treatment
- Neurologic disease or movement disorder
- Other medical conditions or drug therapy that could affect RLS efficacy assessments or may present a safety concern
- Have clinically significant or unstable medical conditions
- Have active suicidal plan/intent or has had active suicidal thoughts in the past 6 months; has a history of suicide attempt
Data sourced from ClinicalTrials.gov (NCT01668667). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.