RCT for Pregabalin in Restless Legs Syndrome in South Korea
Condition: Restless Legs Syndrome
MeSH terms: Psychomotor Agitation; Restless Legs Syndrome; Syndrome
Study type: Interventional
Phase: Phase 3

Summary: 
      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.
    

Detailed 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.
    

Intervention name(s): Pregabalin 75mg; Placebos
Intervention type(s): Drug; Drug
Intervention description(s): Pregabalin 75 mg capsule; Placebo capsule
Intervention MeSH terms: Pregabalin
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: A randomized, double-blind, placebo-controlled, multicenter clinical trial. Study subjects will be recruited from 4 medical centers in South Korea.
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Restless legs syndrome; pregabalin; Willis-Ekbom disease