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Study on the Effects of Dextromethadone Hydrochloride for Patients with Moderate to Very Severe Restless Legs Syndrome

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a medication called REL-1017, which contains the active ingredient dextromethadone hydrochloride. The study is aimed at individuals with Restless Legs Syndrome (RLS), a condition that causes an uncontrollable urge to move the legs, often accompanied by uncomfortable sensations. The trial will explore how effective, safe, and tolerable this medication is for people experiencing moderate to very severe symptoms of RLS, which may also include periodic limb movements during sleep.

The purpose of the study is to compare the effects of REL-1017 with a placebo over a period of 30 days. Participants will take a daily dose of 25 mg of the medication. The study will involve several assessments to monitor changes in RLS symptoms and sleep patterns. These assessments will take place at the beginning of the study, after 10 days, and at the end of the 30-day treatment period. The goal is to determine if the medication can significantly reduce the severity of RLS symptoms and improve sleep quality.

Throughout the study, participants will be monitored to ensure their safety and to evaluate how well they tolerate the medication. The trial is designed to provide valuable insights into the potential benefits of REL-1017 for individuals suffering from RLS, with the hope of finding a new treatment option for this challenging condition.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on age (18-75 years) and a diagnosis of primary restless leg syndrome (RLS) with a severity score greater than 10.

  2. Step 2

    Baseline assessment

    Initial assessments are conducted to establish baseline measurements. These include the International RLS Rating Scale (IRLS-RS) score and sleep parameters such as total sleep time, sleep latency, and sleep efficacy.

  3. Step 3

    Medication administration

    The study involves daily dosing with 25 mg of REL-1017 or a placebo for a period of 30 days. The medication is administered orally in tablet form.

  4. Step 4

    10-day assessment

    On Day 11, assessments are performed to evaluate changes in RLS symptoms and sleep parameters. This includes measuring the IRLS-RS score and sleep metrics such as total sleep time, sleep latency, and sleep efficacy.

  5. Step 5

    End of treatment assessment

    On Day 30, the end of the treatment period, further assessments are conducted to determine the percentage of responders, defined as those with a 50% reduction in the IRLS-RS score from baseline.

  6. Step 6

    Follow-up assessment

    A follow-up assessment is conducted on Day 31 and Day 37 to evaluate the persistence of treatment effects and any changes in RLS symptoms and sleep parameters.

Who can join the trial?

4 criteria

  • Both men and women can participate.
  • Participants must be between 18 and 75 years old, including those ages.
  • Participants must have a diagnosis of primary restless leg syndrome (RLS). This means they have been told by a doctor that they have this condition.
  • Participants must have moderate to very severe RLS. This is determined by a score called the IRLS-RS, which should be greater than 10. The IRLS-RS is a way to measure how bad the symptoms are.

Who cannot join the trial?

5 criteria

  • Patients who are not diagnosed with restless leg syndrome cannot participate. Restless leg syndrome is a condition that causes an uncontrollable urge to move your legs, usually due to an uncomfortable sensation.
  • Patients who are not within the specified age range cannot participate. The study is open to certain age groups, so if you are outside this range, you would be excluded.
  • Patients who are part of a vulnerable population cannot participate. Vulnerable populations include groups that may have additional risks or need special protection in research.
  • Patients who do not meet the criteria for moderate to very severe restless leg syndrome cannot participate. This means that if your symptoms are mild, you would not be eligible.
  • Patients who are not willing or able to follow the study procedures cannot participate. This includes taking the study medication as directed and attending all required visits.
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Investigated drugs

d-Methadone: This medication is being studied for its potential to help people with Restless Legs Syndrome (RLS), a condition that causes uncomfortable sensations in the legs and an irresistible urge to move them. The study is looking at how effective, safe, and tolerable d-Methadone is for people with moderate to very severe RLS.

What is already known about the treatment

d-Methadone – This medication is administered orally and is currently being studied in clinical trials for its potential use in treating restless leg syndrome (RLS). It is in the phase 2 stage of clinical trials, where its efficacy, safety, and tolerability are being evaluated. The main therapeutic indication for d-Methadone is moderate to very severe restless leg syndrome with periodic limb movements. At the molecular level, d-Methadone works by modulating the activity of NMDA receptors in the brain, which are involved in pain and neurological functions. It is classified pharmacologically as an NMDA receptor antagonist.

Investigated diseases

Restless Legs Syndrome – Restless Legs Syndrome (RLS) is a neurological disorder characterized by an uncontrollable urge to move the legs, usually due to uncomfortable sensations. These sensations often occur in the evening or nighttime hours when a person is sitting or lying down. The condition can lead to difficulties in falling or staying asleep, which can result in daytime fatigue. The severity of symptoms can vary from mild to severe and may fluctuate in intensity. Movement, such as walking or stretching, typically provides temporary relief from the discomfort. RLS can affect daily activities and quality of life, as it often disrupts sleep and can lead to exhaustion.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-510968-22-00Protocol codeNSI-RLS-001Estimated enrolment50 patientsSponsorEnte Ospedaliero Cantonale (EOC)

sourced from the EU Clinical Trials Register and site verification

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