Myotonic DisordersNCT07154654
Prospective, Long Term, Observational Study (Patient Registry) of Paediatric Myotonic Disorders
An observational study of Myotonic Disorders, run by Lupin Ltd. at 1 site in France.
Trial summary
This is a prospective, open-label, multi-centre, single arm, registry study to collect standard relevant clinical and epidemiological data during routine medical evaluation and treatment in paediatric patients with myotonic disorders who are being treated with mexiletine therapy according to the physician. Read more about this study
- Who is it for?
- Ages Up to 6 years
- Conditions the study is for
- Myotonic Disorders
- What is being tested?
- Mexiletine
- How many people
- 10 participants
- Where
- 1 siteFrance
- Study dates
- 30 Sep 2025to 22 Feb 2028
- How long will I take part?
- 2 Years
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 Up to 6 years
- All sexes
- Child
Study population: The study population will include male and female children from birth to less than 6 years of age with clinical symptoms or signs of myotonic disorders, normal electrocardiogram (ECG) exam and genetic confirmation of the diagnosis i.e., non-dystrophic myotonia (NDM), or myotonic dystrophy (DM) type 1 (DM1), or DM type 2 (DM2), and who comply with the inclusion / exclusion criteria. Patients will be enrolled consecutively at each site in order to minimize selection bias
Who may be able to join
- Male or female patients from birth to less than 6 years
- A genetically confirmed diagnosis of NDM or DM (DM1or DM2), as per the treating clinician.
- Presence of clinical symptoms of myotonia (hand grip myotonia, myotonia in the leg muscles, any other myotonia symptoms) to be confirmed by the treating clinician.
- Patients already receiving mexiletine treatment or who are clinically considered for mexiletine treatment as per the treating physician judgement.
- No history of or significant cardiac abnormalities as determined by a cardiologist's assessment of the ECG and echocardiogram performed prior to enrolment in the study or as per the treating physician standard of care (NaMuscla SmPC, 2023)
- No known history or signs and symptoms of any significant liver disorder as per treating physician.
- No known clinically relevant abnormal laboratory investigations for haematology, biochemistry, and urinalysis values at screening (or based on values obtained within 3 months prior to screening in patient's medical record) that could affect the study objectives as judged by the treating physician.
- Parent or legal guardian able to provide consent/assent to study participation and to sign the written informed consent or non-opposition as per local regulatory requirements prior to study entry and perform any study-related activity. -
Who cannot join
- Any contraindication to mexiletine as listed in the Namuscla Summary of Product Characteristics (SmPC) (NaMuscla SmPC, 2023)
- Hypersensitivity to the active substance, or to any of the excipients
- Hypersensitivity to any local anaesthetic
- Ventricular tachyarrhythmia
- Complete heart block (i.e., third-degree atrioventricular block) or any heart block susceptible to evolve to complete heart block (first-degree atrioventricular block with markedly prolonged PR interval (≥ 200 ms) and/or wide QRS complex (≥ 120 ms), second-degree atrioventricular block, bundle branch block, bifascicular and trifascicular block),
- QT interval > 450ms
Show all 18Show fewer
- Myocardial infarction (acute or past), or abnormal Q-waves
- Symptomatic coronary artery disease
- Heart failure with ejection fraction <50%
- Atrial tachyarrhythmia, fibrillation or flutter
- Sinus node dysfunction (including sinus rate < 50 bpm)
- Co-administration with medicinal products inducing torsades de pointes.
- Co-administration with medicinal products with narrow therapeutic index
- Any other neurological or psychiatric condition that might affect the study assessments, as per the treating clinician.
- Any clinically significant illness, laboratory findings, ECG, or other clinical symptoms, which in the opinion of the treating physician could affect the patient's optimal participation in the study
- Receiving strong inducers or inhibitors of CYP2D6 or CYP1A2 or planned to receive them, during the subject participation (See section 4.1.5.1 Prohibited medications).
- Any concurrent illness, or medications which could affect the muscle function, and confound the results according to the treating physician.
- Seizure disorder, diabetes mellitus requiring treatment by insulin.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
Centre Hospitalier Universitaire de Clermont-Ferrand
Clermont-Ferrand
Catherine Sarret, csarret@chu-clermontferrand.fr
Catherine Sarret
About this study
Official title: Prospective, Long Term, Observational Study (Patient Registry) of Paediatric Myotonic Disorders From Birth to Less Than Six Years of Age Who Are Treated With Mexiletine (PEGASUS Study).
This is a prospective, open-label, multi-centre, single arm, registry study to collect standard relevant clinical and epidemiological data during routine medical evaluation and treatment in paediatric patients with myotonic disorders who are being treated with mexiletine therapy according to the physician.
Read the detailed description
This is a prospective, open-label, multi-centre, single arm, registry study to collect standard relevant clinical and epidemiological data during routine medical evaluation and treatment in paediatric patients with myotonic disorders who are being treated with mexiletine therapy according to the physician.
Patients who meet the eligibility criteria will be enrolled in 2 cohorts by age groups although cohorts are not enrolled sequentially (cohort definition is to assure minimum requirements for meeting PIP agreements).
Cohort 1 - Infants and children aged between 6 months to less than 6 years. Cohort 2 - Neonates and infants from birth to less than 6 months. The overall treatment duration follow-up for each cohort will be at least 2 years.
- Conditions
- Myotonic Disorders
- Being tested
- Mexiletine
- Medical subject headings
- Myotonic Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MexiletineDrug
Non interventional
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 | Infants and children aged between 6 months to less than 6 years. Receives: Drug: Mexiletine | |
| Cohort 2 | Neonates and infants from birth to less than 6 months. Receives: Drug: Mexiletine |
What is being measured
The primary outcome is the main question the study is designed to answer.
To assess long-term safety by collection of SAEs, AEs, AESIs, changes in frequency, treatment interruptions
Number and frequency of adverse events (AEs), serious adverse events (SAEs) and AE leading to treatment discontinuation, throughout the study while on treatment with mexiletine; Incidence of adverse events of special interest (AESI), namely: Severe Cutaneous Adverse Reactions (SCARs) \& Cardiac arrhythmia. Increased frequency of seizure episodes in patients with epilepsy; Any changes in frequency, treatment interruptions of mexiletine
Measured: Baseline to 24 months
Secondary outcomes (4)
To assess the suitability of mexiletine administration
To assess the suitability of mexiletine administration using available formulations including, where appropriate, capsules or opening and sprinkling contents in food or drink according to the child´s age (from birth to less than 6 years) and ability to swallow.
Measured: Baseline to 24 months
To understand how mexiletine is used by clinicians
To understand how mexiletine is used by clinicians who have previously decided to use mexiletine for the treatment of myotonia in myotonic disorder patients, from birth to less than 6 years over a at least 2 years period, to establish risk:benefit conclusions.
Measured: Baseline to 24 months
Description over time of outcomes of mexiletine use
Description over time of outcomes of mexiletine use including dosing, formulation used, method of administration, acceptability and palatability as per the data collected by the treating physician according to age and cohort.
Measured: Baseline to 24 months
The treating physician with elaborate a brief text with risk-benefit conclusions
Description over time of any efficacy outcomes obtained from clinically indicated tests as per the treating physician typical clinical practice and according to patient's age and cohort.
Measured: Baseline to 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Sep 2025
- Study start30 Sep 2025 (estimated)
- Primary completion22 Nov 2027 (estimated)
- Study completion22 Feb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Myotonic DisordersStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 10 participants (estimated)
- Target duration
- 2 Years
Sponsor and investigators
- Lead sponsor
- Lupin Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Catharine Sarret, MD, Principal investigator, University Hospital, Clermont-Ferrand
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07154654
- Sponsor's protocol ID
- MEX-NM-401
- Status last verified
- Sep 2025
- First submitted
- 24 Jul 2025
- Last updated
- 23 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective, Long Term, Observational Study (Patient Registry) of Paediatric Myotonic Disorders From Birth to Less Than Six Years of Age Who Are Treated With Mexiletine (PEGASUS Study).
- ClinicalTrials.gov ID
- NCT07154654
- Acronym / sponsor ID
- MEX-NM-401
- Conditions
- Myotonic Disorders
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- Lupin Ltd.Industry (pharma, biotech, devices)
- Study start
- 30 Sep 2025 (estimated)
- Primary completion
- 22 Nov 2027 (estimated)
- Study completion
- 22 Feb 2028 (estimated)
- First posted
- 4 Sep 2025 (actual)
- 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.
This is a prospective, open-label, multi-centre, single arm, registry study to collect standard relevant clinical and epidemiological data during routine medical evaluation and treatment in paediatric patients with myotonic disorders who are being treated with mexiletine therapy according to the physician.
Detailed description
This is a prospective, open-label, multi-centre, single arm, registry study to collect standard relevant clinical and epidemiological data during routine medical evaluation and treatment in paediatric patients with myotonic disorders who are being treated with mexiletine therapy according to the physician.
Patients who meet the eligibility criteria will be enrolled in 2 cohorts by age groups although cohorts are not enrolled sequentially (cohort definition is to assure minimum requirements for meeting PIP agreements).
Cohort 1 - Infants and children aged between 6 months to less than 6 years. Cohort 2 - Neonates and infants from birth to less than 6 months. The overall treatment duration follow-up for each cohort will be at least 2 years.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 2 Years
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 | – | Drug: MexiletineInfants and children aged between 6 months to less than 6 years. |
| Cohort 2 | – | Drug: MexiletineNeonates and infants from birth to less than 6 months. |
Who may qualify
- Ages
- Up to 6 years
- Sex
- All
- Age groups
- Child
- Study population
- The study population will include male and female children from birth to less than 6 years of age with clinical symptoms or signs of myotonic disorders, normal electrocardiogram (ECG) exam and genetic confirmation of the diagnosis i.e., non-dystrophic myotonia (NDM), or myotonic dystrophy (DM) type 1 (DM1), or DM type 2 (DM2), and who comply with the inclusion / exclusion criteria. Patients will be enrolled consecutively at each site in order to minimize selection bias
Key inclusion criteria (8 listed)
- Male or female patients from birth to less than 6 years
- A genetically confirmed diagnosis of NDM or DM (DM1or DM2), as per the treating clinician.
- Presence of clinical symptoms of myotonia (hand grip myotonia, myotonia in the leg muscles, any other myotonia symptoms) to be confirmed by the treating clinician.
- Patients already receiving mexiletine treatment or who are clinically considered for mexiletine treatment as per the treating physician judgement.
- No history of or significant cardiac abnormalities as determined by a cardiologist's assessment of the ECG and echocardiogram performed prior to enrolment in the study or as per the treating physician standard of care (NaMuscla SmPC, 2023)
Key exclusion criteria (18 listed)
- Any contraindication to mexiletine as listed in the Namuscla Summary of Product Characteristics (SmPC) (NaMuscla SmPC, 2023)
- Any other neurological or psychiatric condition that might affect the study assessments, as per the treating clinician.
- Any clinically significant illness, laboratory findings, ECG, or other clinical symptoms, which in the opinion of the treating physician could affect the patient's optimal participation in the study
- Receiving strong inducers or inhibitors of CYP2D6 or CYP1A2 or planned to receive them, during the subject participation (See section 4.1.5.1 Prohibited medications).
- Any concurrent illness, or medications which could affect the muscle function, and confound the results according to the treating physician.
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 |
|---|---|---|
| MexiletineNon interventional | Drug | Cohort 1, Cohort 2 |
Primary outcome
To assess long-term safety by collection of SAEs, AEs, AESIs, changes in frequency, treatment interruptions
Time frame: Baseline to 24 months
Number and frequency of adverse events (AEs), serious adverse events (SAEs) and AE leading to treatment discontinuation, throughout the study while on treatment with mexiletine; Incidence of adverse events of special interest (AESI), namely: Severe Cutaneous Adverse Reactions (SCARs) \& Cardiac arrhythmia. Increased frequency of seizure episodes in patients with epilepsy; Any changes in frequency, treatment interruptions of mexiletine
4 secondary outcomes
To assess the suitability of mexiletine administration
Time frame: Baseline to 24 months
To understand how mexiletine is used by clinicians
Time frame: Baseline to 24 months
Description over time of outcomes of mexiletine use
Time frame: Baseline to 24 months
The treating physician with elaborate a brief text with risk-benefit conclusions
Time frame: Baseline to 24 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2025.
Related trials for Myotonic Disorders
RecruitingPhase 3
Efficacy, Safety, and Tolerability of Zeleciment Basivarsen (DYNE-101) in Participants With Myotonic Dystrophy Type 1
Myotonic Dystrophy Type 1 (DM1), DM1
RecruitingObservational study
Development of Non-Invasive Prenatal Diagnosis for Single Gene Disorders
Invasive PreNatal Diagnosis in a Context of Family History of Single-gene Disorders, Including, Sickle Cell Disease
Enrolling by invitationPhase 2
A Study of Long-term Safety and Efficacy of VX-670 in Participants With Myotonic Dystrophy Type I
Myotonic Dystrophy Type 1 (DM1)
RecruitingPhase 3
A Phase 3 Study to Evaluate the Safety and Efficacy of AOC 1044 (Also Referred to as Delpacibart Zotadirsen) in Participants With DMD With Gene Mutations Amenable to Exon 44 Skipping
Muscular Dystrophies, Muscular Dystrophies (Duchenne, Becker, Myotonic Dystrophy)
Active, not recruitingPhase 1/2
A Phase 1/2 Study of VX-670 in Adult Participants With Myotonic Dystrophy 1 (DM1)
Myotonic Dystrophy Type 1 (DM1)
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.
Catharine Sarret, MD principal investigator
University Hospital, Clermont-Ferrand
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Myotonic Disorders, run by Lupin Ltd. 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 8 inclusion and 18 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: looking for participants now, as of the sponsor's last update on 23 Sep 2025. 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Nikki Adetoro (4434474534, nikkiadetoro@lupin.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To assess long-term safety by collection of SAEs, AEs, AESIs, changes in frequency, treatment interruptions (time frame: Baseline to 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Sep 2025.