Mexiletine and Non Dystrophic Myotonias

• Register: ClinicalTrials.gov
• Last refreshed on: 19 February 2015
• Main ID: NCT02336477
• Date of registration: 08/01/2015
• Prospective Registration: No
• Primary sponsor: Assistance Publique - Hôpitaux de Paris
• Public title: Mexiletine and Non Dystrophic Myotonias MYOMEX
• Scientific title: Efficacy and Safety of Mexiletine in Non-dystrophic Myotonias
• Date of first enrolment: June 2011
• Target sample size: 24
• Recruitment status: Completed
• URL: http://clinicaltrials.gov/show/NCT02336477
• Study type: Interventional
• Study design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment
• Phase: Phase 3

Countries of recruitment

France

Contacts

• Name: Savine Vicart, MD
• Affiliation: Assistance Publique - Hôpitaux de Paris

• Name: Bertrand Fontaine, MD, PhD
• Affiliation: Assistance Publique - Hôpitaux de Paris

Key inclusion & exclusion criteria

Inclusion criteria :

- Genetically definite MC and PC.

- Male and female participants, age between 18 and 65 who are able to comply with the
study conditions.

- Participants who experience myotonic symptoms severe enough to justify treatment.

The severity will be evaluated on:

- Clinical criteria: myotonia is considered as severe if it involves at least two
segments (upper limb, lower limb or face)

- Disabling criteria: myotonia is considered severe if patients notice impacts on at
least 3 of the 7 daily activities listed in the disabling section of the clinical
myotonia scale (Annex 2).

Thus, patients who experience myotonic symptoms severe enough to justify treatment are
those with myotonia that involves at least two segments and that have an impact on at
least 3 daily activities.

- Participants who are drug naive or those who receiving mexiletine at Effective dosage
and agreeing to stop treatment at least four days before inclusion .

- Pregnancy: Women: non-childbearing potential (i.e., postmenopausal or Surgically
sterile) or must use a medically accepted contraceptive regimen; a pregnancy test
will ensure that they are not pregnant.

- Normal cardiac exam performed by a cardiologist including EKG, and Cardiac ultrasound
(if not done within 3 months before trial).

Exclusion criteria :

- Intercurrent event which could interfere with the muscle function (infection,trauma,
fracture, …)

- Coincidental renal, hepatic, respiratory, thyroid, other neuromuscular disease or
heart disease that will contraindicate mexiletine or interfere with clinical
evaluation.

- Use of any of the following medications that can interfere with muscle function
:diuretics, anti epileptics (sodium channel blockers), antiarrhythmics,
corticosteroids, beta-blockers,

- Allergy to mexiletine



Age minimum: 18 Years
Age maximum: 65 Years
Gender: Both

Health Condition(s) or Problem(s) studied

Non-dystrophic Myotonias

Paramyotonia Congenita

Myotonia Congenita

Intervention(s)

Drug: Mexiletine

Drug: placebo

Primary Outcome(s)

score of stiffness severity on a self-assessment scale (100 mm VAS) [Time Frame: 18 days]

Secondary Outcome(s)

standardized EMG measures after repetitive short exercise test at cold and long exercise test [Time Frame: 18 days]

chair test: time needed to stand up from a chair, walk around it and sit down again [Time Frame: 18 days]

CGI efficacy (Clinical Global Impression- Efficacy index) [Time Frame: 18 days]

quality of life scale (INQOL) [Time Frame: 18 days]

severity and disability scale of myotonia to be validated [Time Frame: 18 days]

Secondary ID(s)

P091101

Source(s) of Monetary Support

Please refer to primary and secondary sponsors