Restless Legs SyndromePhase 2SOXISNCT00949806
Restless Legs Syndrome Treatment With Botulinum Toxin
A Phase 2 study testing BNT (intradermal injection) in people with Restless Legs Syndrome, run by University Hospital, Bordeaux at 1 site in France.
Trial summary
Restless Legs Syndrome (RLS) is a common sensori-motor disorder that causes sensory discomfort and motor restlessness, most often in the legs, which improves with movement. Although medications are available to treat the disorder, many people either experience side effects that prevent them from continuing on the… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Restless Legs Syndrome
- What is being tested?
- BNT (intradermal injection)
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 27 participants
- Where
- 1 siteFrance
- Study dates
- Aug 2009to Nov 2011
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or female > 18 years old
- Normal neurological clinical examination
- A minimum score of 21 on the RLS severity rating scale
- Primary RLS diagnosis based on (i) the presence of a characteristic clinical history and on (ii) the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria.
- Medications regimen for RLS must be stabilized for more than 6 weeks prior to entering the study
- informed consent
Who cannot join
- Medical history of diabetes, depression, kidney failure, myasthenia
- Iron deficiency
- Pregnancy, lactation, woman of childbearing age without efficient contraceptive method
- Patient undergoing aminosid antibiotherapy or BNT injection for other indication
- Any contra-indication to BNT injection
- Participation to other clinical study within 30 days
- Patient under any administrative or legal supervision
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Phase II Non Comparative, Open Study to Assess the Efficacy and Safety of the Botulinum Toxin Type A in Patients With Restless Legs Syndrome (RLS)
Restless Legs Syndrome (RLS) is a common sensori-motor disorder that causes sensory discomfort and motor restlessness, most often in the legs, which improves with movement. Although medications are available to treat the disorder, many people either experience side effects that prevent them from continuing on the medication or do not sufficiently respond to current RLS medications. Recently, botulinum toxin type A (BNT) has been reported to relief RLS in patients with severe symptoms but this was not confirmed by other anecdotal reports. The investigators propose to test the efficacy of BNT on RLS symptoms by designing a more controlled study. Ultimately, this may lead to extend the therapeutic arsenal of this disorder.
Read the detailed description
The restless legs syndrome (RLS) is a chronic sensori-motor disorder affecting an estimated 7.2% to 11.5% of the adult population. It is characterised by a complaint of an irresistible urge to move the legs. This urge can often be accompanied by pain or other uncomfortable and unpleasant sensations, it either occurs or worsens with rest particularly at night, and improves with activity. RLS is diagnosed clinically by means of the four essential criteria established by the International Restless Legs Syndrome Study Group.
There is still no comprehensive understanding of the underlying pathophysiological processes of RLS, but the evidence for a primary dopaminergic role in RLS is to be found in the excellent pharmacological response to low-dose dopaminergic medications. Another recent evidence suggests an enhanced sensitization of central pain processing in patients with RLS. This had led to consider the botulinum toxin type A (BNT) as an alternative treatment in patients refractory to current RLS medications or in those suffering from adverse events. The therapeutic benefit of BNT injection in patients with recalcitrant RLS has been anecdotally reported lately but not confirmed by other reports.
The aim of our study is to evaluate the efficacy and tolerance of intradermal BNT injection in severely affected patients with idiopathic RLS.
For this we designed a phase II non comparative, open study. Patients with severe RLS will receive a one-time intradermal administration of BNT into the most symptomatic areas of both legs. Injections will be distributed in a grid distribution pattern covering a total of 20 equidistant sites per symptomatic area. Each symptomatic area will receive a maximum 250 units of BNT (12.5 units per injection). The total BNT injected units should not exceed 1000 units per patient.
Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks following BNT administration and assessed by mean of the International RLS Rating Scale and Clinical Global Impression Scale.
- Conditions
- Restless Legs Syndrome
- Being tested
- BNT (intradermal injection)
- Keywords
- Botulinum toxin
- Medical subject headings
- Restless Legs Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BNT (intradermal injection)Drug
Patients with severe RLS will receive a one-time intradermal administration of BNT into the most symptomatic areas of both legs.
Injections will be distributed in a grid distribution pattern covering a total of 20 equidistant sites per symptomatic area. Each symptomatic area will receive a maximum 250 units of BNT (12.5 units per injection). The total BNT injected units should not exceed 1000 units per patient.
| Study group | Role | What they receive |
|---|---|---|
| Administrated | Experimental | All patients included will receive an intradermal administration of BNT Receives: Drug: BNT (intradermal injection) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Efficacy of BNT in the treatment of RLS measured by at least 50% improvement of the RLS severity score as measured by the International Restless Legs Syndrome Severity Scale (IRLSRS) at day 15 following BNT injection
Measured: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks.
Secondary outcomes (3)
Efficacy duration (maintenance of at least 50% improvement of the RLS severity on the IRLSRS at week 6, 12, 18 and 24 compared to baseline severity score
Measured: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks
Adverse events of BNT injection
Measured: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks
Clinical Global Impression (CGI) improvement
Measured: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jul 2009 (estimated)
- Study startAug 2009
- Primary completionMay 2011
- Study completionNov 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Restless Legs SyndromeStudies of the same condition, open and under way.
- More trials run by University Hospital, BordeauxThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 27 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Bordeaux
- Sponsor type
- University, hospital or other
- Collaborators
- IPSEN PHARMA S.A.S
- Responsible party
- Sponsor
- Investigators
- Imad GHORAYEB, MD, PhD, Principal investigator, University Hospital Bordeaux, France
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00949806
- Sponsor's protocol ID
- CHUBX 2008/35
- Other IDs
- 2009-011386-92, 2009
- Acronym
- SOXIS
- Status last verified
- Jul 2012
- First submitted
- 29 Jul 2009
- Last updated
- 12 May 2026
- Results posted
- No
- Data monitoring committee
- No
Publications
Rotenberg JS, Canard K, Difazio M. Successful treatment of recalcitrant restless legs syndrome with botulinum toxin type-A. J Clin Sleep Med. 2006 Jul 15;2(3):275-8.
PubMed 17561538Ghorayeb I, Burbaud P. Failure of botulinum toxin A to relieve restless legs syndrome. Sleep Med. 2009 Mar;10(3):394-5. doi: 10.1016/j.sleep.2008.03.002. Epub 2008 May 29. No abstract available.
PubMed 18514023Nahab FB, Peckham EL, Hallett M. Double-blind, placebo-controlled, pilot trial of botulinum toxin A in restless legs syndrome. Neurology. 2008 Sep 16;71(12):950-1. doi: 10.1212/01.wnl.0000325994.93782.a1. No abstract available.
PubMed 18794499Ghorayeb I, Benard A, Vivot A, Tison F, Burbaud P. A phase II, open-label, non-comparative study of Botulinum toxin in Restless Legs Syndrome. Sleep Med. 2012 Dec;13(10):1313-6. doi: 10.1016/j.sleep.2012.08.019. Epub 2012 Oct 11.
PubMed 23063302
Study at a glance
From the registry record, last updated by the sponsor on 12 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase II Non Comparative, Open Study to Assess the Efficacy and Safety of the Botulinum Toxin Type A in Patients With Restless Legs Syndrome (RLS)
- ClinicalTrials.gov ID
- NCT00949806
- Acronym / sponsor ID
- SOXIS / CHUBX 2008/35
- Conditions
- Restless Legs Syndrome
- Keywords
- Botulinum toxin
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 27 participants (actual)
- Lead sponsor
- University Hospital, BordeauxUniversity, hospital or other
- Collaborators
- IPSEN PHARMA S.A.S
- Study start
- Aug 2009
- Primary completion
- May 2011 (actual)
- Study completion
- Nov 2011 (actual)
- First posted
- 30 Jul 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Restless Legs Syndrome (RLS) is a common sensori-motor disorder that causes sensory discomfort and motor restlessness, most often in the legs, which improves with movement. Although medications are available to treat the disorder, many people either experience side effects that prevent them from continuing on the medication or do not sufficiently respond to current RLS medications. Recently, botulinum toxin type A (BNT) has been reported to relief RLS in patients with severe symptoms but this was not confirmed by other anecdotal reports. The investigators propose to test the efficacy of BNT on RLS symptoms by designing a more controlled study. Ultimately, this may lead to extend the therapeutic arsenal of this disorder.
Detailed description
The restless legs syndrome (RLS) is a chronic sensori-motor disorder affecting an estimated 7.2% to 11.5% of the adult population. It is characterised by a complaint of an irresistible urge to move the legs. This urge can often be accompanied by pain or other uncomfortable and unpleasant sensations, it either occurs or worsens with rest particularly at night, and improves with activity. RLS is diagnosed clinically by means of the four essential criteria established by the International Restless Legs Syndrome Study Group.
There is still no comprehensive understanding of the underlying pathophysiological processes of RLS, but the evidence for a primary dopaminergic role in RLS is to be found in the excellent pharmacological response to low-dose dopaminergic medications. Another recent evidence suggests an enhanced sensitization of central pain processing in patients with RLS. This had led to consider the botulinum toxin type A (BNT) as an alternative treatment in patients refractory to current RLS medications or in those suffering from adverse events. The therapeutic benefit of BNT injection in patients with recalcitrant RLS has been anecdotally reported lately but not confirmed by other reports.
The aim of our study is to evaluate the efficacy and tolerance of intradermal BNT injection in severely affected patients with idiopathic RLS.
For this we designed a phase II non comparative, open study. Patients with severe RLS will receive a one-time intradermal administration of BNT into the most symptomatic areas of both legs. Injections will be distributed in a grid distribution pattern covering a total of 20 equidistant sites per symptomatic area. Each symptomatic area will receive a maximum 250 units of BNT (12.5 units per injection). The total BNT injected units should not exceed 1000 units per patient.
Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks following BNT administration and assessed by mean of the International RLS Rating Scale and Clinical Global Impression Scale.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Administrated | Experimental | Drug: BNT (intradermal injection)All patients included will receive an intradermal administration of BNT |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Male or female > 18 years old
- Normal neurological clinical examination
- A minimum score of 21 on the RLS severity rating scale
- Primary RLS diagnosis based on (i) the presence of a characteristic clinical history and on (ii) the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria.
- Medications regimen for RLS must be stabilized for more than 6 weeks prior to entering the study
Key exclusion criteria (7 listed)
- Medical history of diabetes, depression, kidney failure, myasthenia
- Iron deficiency
- Pregnancy, lactation, woman of childbearing age without efficient contraceptive method
- Patient undergoing aminosid antibiotherapy or BNT injection for other indication
- Any contra-indication to BNT injection
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| BNT (intradermal injection)Patients with severe RLS will receive a one-time intradermal administration of BNT into the most symptomatic areas of both legs. Injections will be distributed in a grid distribution pattern covering a total of 20 equidistant sites per symptomatic area. Each symptomatic area will receive a maximum 250 units of BNT (12.5 units per injection). The total BNT injected units should not exceed 1000 units per patient. | Drug | Administrated |
Primary outcome
Efficacy of BNT in the treatment of RLS measured by at least 50% improvement of the RLS severity score as measured by the International Restless Legs Syndrome Severity Scale (IRLSRS) at day 15 following BNT injection
Time frame: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks.
3 secondary outcomes
Efficacy duration (maintenance of at least 50% improvement of the RLS severity on the IRLSRS at week 6, 12, 18 and 24 compared to baseline severity score
Time frame: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks
Adverse events of BNT injection
Time frame: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks
Clinical Global Impression (CGI) improvement
Time frame: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 May 2026.
- Background: PubMed 17561538Rotenberg JS, Canard K, Difazio M. Successful treatment of recalcitrant restless legs syndrome with botulinum toxin type-A. J Clin Sleep Med. 2006 Jul 15;2(3):275-8.
- Background: PubMed 18514023Ghorayeb I, Burbaud P. Failure of botulinum toxin A to relieve restless legs syndrome. Sleep Med. 2009 Mar;10(3):394-5. doi: 10.1016/j.sleep.2008.03.002. Epub 2008 May 29. No abstract available.
- Background: PubMed 18794499Nahab FB, Peckham EL, Hallett M. Double-blind, placebo-controlled, pilot trial of botulinum toxin A in restless legs syndrome. Neurology. 2008 Sep 16;71(12):950-1. doi: 10.1212/01.wnl.0000325994.93782.a1. No abstract available.
- Derived from this study: PubMed 23063302Ghorayeb I, Benard A, Vivot A, Tison F, Burbaud P. A phase II, open-label, non-comparative study of Botulinum toxin in Restless Legs Syndrome. Sleep Med. 2012 Dec;13(10):1313-6. doi: 10.1016/j.sleep.2012.08.019. Epub 2012 Oct 11.
Related trials for Restless Legs Syndrome
RecruitingObservational study
Lemborexant vs Clonidine vs Sedatives to Treat Insomnia in Chronic Pain Patients
Chronic Insomnia, Chronic Pain
Not yet recruiting
Neuromodulation to Overcome Severe Restless Legs Syndrome
Restless Leg Syndrome (RLS), Spinal Cord Stimulation (SCS)
Not yet recruitingPhase 2
Tolerability and Efficacy of CBD Extract for RLS Treatment
Restless Leg Syndrome
Recruiting
Functional Connectivity of the Interoceptive Network in RLS
Restless Legs Syndrome
Not yet recruitingPhase 2
Intravenous Iron in the Management of Drug-resistant Restless Legs syndromeI
Restless Legs Syndrome (RLS)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Imad GHORAYEB, MD, PhD principal investigator
University Hospital Bordeaux, France
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing BNT (intradermal injection) in people with Restless Legs Syndrome, run by University Hospital, Bordeaux at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Efficacy of BNT in the treatment of RLS measured by at least 50% improvement of the RLS severity score as measured by the International Restless Legs Syndrome Severity Scale (IRLSRS) at day 15 following BNT injection (time frame: Outcome measures will be evaluated at baseline, then at 2, 6, 12, 18 and 24 weeks.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00949806, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 May 2026; AzTrials last refreshed its copy on 6 Nov 2026.