RCT for Pregabalin in Restless Legs Syndrome in South Korea

Seoul National University

Status and phase

Completed

Phase 3

Conditions

Restless Legs Syndrome

Treatments

Drug: Pregabalin 75mg

Drug: Placebos

Study type

Interventional

Funder types

Other

Identifiers

NCT04161027

1903-121-1021

Details and patient eligibility

About

This randomized, double-blind, placebo-controlled, multicenter clinical trial is designed to to assess the treatment efficacy and tolerability of pregabalin in patients with idiopathic restless legs syndrome in South Korea.

Full description

Objectives: To assess the treatment efficacy and tolerability of pregabalin in patients with idiopathic restless legs syndrome (RLS) in South Korea.

Study Design: A randomized, double-blind, placebo-controlled, multicenter clinical trial Study period: total 14 weeks: 2 weeks for placebo run in period and 12 weeks treatment after randomization (titration for 4 weeks and maintenance for 8 weeks).

Subjects: a total number of 100 participants (randomly assigned 1:1 to pregabalin or placebo). The sample number was calculated based on a superiority design, 1-sided, alpha 0.05 with power 80% and drop rate 10%.

Inclusion criteria: adults aged between 19-80 and diagnosed with idiopathic RLS with IRLS score of 15 or more.

Exclusion criteria: Secondary RLS; serum ferritin < 10 μg/L or history of oral iron therapy within 3 months or intravenous iron therapy within 1 year; severe comorbid medical or psychiatric disorders; history of pregabalin or gabapentin treatment within 3 months; other comorbid sleep disorders or shift workers.

Treatment schedule and dose

Placebo responders, who showed a decrease of IRLS score of 40% or more, are excluded before randomization. Subjects will randomly assigned to receive either pregabalin or placebo with a 1:1 allocation. A starting dose is 75 mg/day for 2 weeks (taken 1-2 hours before habitual bedtime). At the visit of 2 weeks and 4 weeks, a dose can be titrated by 75-150 mg according to the response and tolerability. A dose ranging 75-300 mg per day will be maintained for 8 weeks.

Primary outcome: changes in IRLS score after 12-week treatment. Secondary outcomes: remission rate (decrease in IRLS score of 50% or more), CGI (clinical global impression)-improvement, changes in 10-cm visual analog scale (VAS), RLS-6, PSQI (pittsburgh sleep quality index), ISI (insomnia severity index), Johns Hopkins RLS QoL after 12-week treatment.

Statistical analysis: ANCOVA for changes in IRLS score with a baseline IRLS score as a covariate.

Tolerability: Safety profiles and Liverpool Adverse Event Profile (LAEP) will be assessed.

Enrollment

116 patients

Sex

All

Ages

19 to 80 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

IRLS (international restless legs scale) score ≥ 15
RLS symptom occurring ≥ 3 times/week and persisting over ≥ 6 months
Drug-naive patients or those who stop taking RLS drugs for ≥ 1 week before screening

Exclusion criteria

Secondary RLS (including iron deficiency anemia, pregnancy, chronic kidney disease [eGFR < 60 mL/min/1.73 m2], peripheral neuropathy, others)
Serum Ferritin < 10 μg/L or history of oral iron therapy within 3 months or intravenous iron therapy within 1 year
Severe comorbid medical or psychiatric disorders
history of pregabalin or gabapentin treatment within 3 months
High risk of obstructive sleep apnea by STOP-BANG questionnaire
Other comorbid sleep disorders or shift workers
Hypersensitivity to pregabalin
Galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption