Mexiletine and Non Dystrophic Myotonias

Phase 3

Completed

• Conditions: Non-dystrophic Myotonias; Myotonia Congenita; Paramyotonia Congenita
• Interventions: Drug: Mexiletine; Drug: placebo

• Registration Number: NCT02336477
• Lead Sponsor: Assistance Publique - Hôpitaux de Paris

Brief Summary

Treatment strategies in non-dystrophic myotonias are based on selective case reports, clinical experience and theoretical benefit. Presently, the most promising antimyotonic medication is mexiletine (MEX) but its manufacturing was stopped. The proposed randomized, double-blind, placebo-controlled, crossover trial is designed to:

1. study the safety and efficacy of mexiletine for the treatment of non-dystrophic myotonias

2. validate electromyographic tests as a standardized outcome measure of myotonia

3. assess the reliability and validity of a new clinical rating scale for myotonia

Detailed Description

A. Specific aims

Treatment strategies in non-dystrophic myotonias are based on selective case reports, clinical experience and theoretical benefit. Presently, the most promising antimyotonic medication is mexiletine (MEX) but its manufacturing was stopped. The proposed randomized, double-blind, placebo-controlled, crossover with wash-out trial is designed to:

* study the safety and efficacy of mexiletine for the treatment of non-dystrophic myotonias

* validate electromyographic tests as a standardized outcome measure of myotonia

* assess the reliability and validity of a new clinical rating scale for myotonia

B. Research design Because of their differing phenotypes, 12 Paramyotonia Congenita and 12 Myotonia Congenita subjects will be enrolled in a stratified trial

C. Outcome variables

1. primary outcome variable: the score of stiffness severity on a self-assessment scale (100 mm VAS) measured at baseline, at the end of phase I and phase II.

2. secondary outcome measures:

* of efficacy:

* standardized EMG measures after repetitive short exercise test at cold and long exercise test

* chair test: time needed to stand up from a chair, walk around it and sit down again

* severity and disability scale of myotonia to be validated)

* quality of life scale (INQOL)

* rate of drop-outs

* of safety:

* adverse event frequency and severity

* EKG

D. Perspectives

It is anticipated that the trial will:

1. provide data that justify recommendations for treatment strategies for myotonic patients

2. provide data to justify AFSAPPS regulatory approval of mexiletine for treatment of myotonia in order to guarantee the availability of the drug for patients

3. develop standardized diagnostic and treatment assessment for non-dystrophic myotonias

Study Timeline

• Study Start: 2011-06
• Primary Completion: 2014-01
• Study Completion: 2014-01
• Status Verified: 2015-01
• Study First Submitted: 2015-01-08
• Study First Submitted QC: 2015-01-12
• Last Update Submitted: 2015-01-12
• Study First Posted: 2015-01-13
• Last Update Posted: 2015-01-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 24

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
2	placebo	Placebo / Mexiletine
1	placebo	Mexiletine / Placebo
1	Mexiletine	Mexiletine / Placebo
2	Mexiletine	Placebo / Mexiletine

Primary Outcome Measures

Name	Time	Method
score of stiffness severity on a self-assessment scale (100 mm VAS)	18 days

Secondary Outcome Measures

Name	Time	Method
CGI efficacy (Clinical Global Impression- Efficacy index)	18 days
standardized EMG measures after repetitive short exercise test at cold and long exercise test	18 days
chair test: time needed to stand up from a chair, walk around it and sit down again	18 days
severity and disability scale of myotonia to be validated	18 days
quality of life scale (INQOL)	18 days

Trial Locations

Locations (1)

Groupe Hospitalier Pitié Salpetriere; 🇫🇷 Paris, France