This trial is active, not recruiting.

Condition myotonic dystrophy
Treatments mexiletine, placebo
Phase phase 2
Sponsor University of Rochester
Start date June 2011
End date March 2017
Trial size 42 participants
Trial identifier NCT01406873, 3716, Funding Source: FDA/OOPD


The purpose of this study is to investigate the effects of mexiletine treatment for 6 months on ambulation, myotonia, muscle function and strength, pain, gastrointestinal functioning, cardiac conduction, and quality of life in myotonic dystrophy type 1 (DM1).

United States No locations recruiting
Other countries No locations recruiting

Study Design

Allocation randomized
Intervention model parallel assignment
Primary purpose treatment
Masking participant, care provider, investigator, outcomes assessor
(Active Comparator)
20 subjects will be randomized (assigned) to receive Mexiletine. Mexiletine is available on the market for the treatment of cardiac arrhythmias, but it is not currently approved for the treatment of myotonia or myotonic dystrophy.
mexiletine Generic name: mexiletine hydrochloride
150 mg/kg Mexiletine capsules taken by mouth, three times daily for 6 months
(Placebo Comparator)
20 subjects will be randomized (assigned) to receive placebo (sugar pill). This control group is necessary to definitely establish the antimyotonic efficacy and safety of mexiletine.
150 mg/kg placebo capsules taken by mouth, three times daily for 6 months

Primary Outcomes

time frame: 6 months

Secondary Outcomes

The Number of Study Participants Who Safely Tolerated mexiletine
time frame: 6 months
time frame: 6 months
Muscle function and strength
time frame: 6 months
Cardiac conduction
time frame: 6 months
Quality of Life
time frame: 6 months

Eligibility Criteria

All participants from 18 years up to 80 years old.

Inclusion Criteria: - A diagnosis of DM1, confirmed by DM1 genetic mutation - Ability to walk 30 feet (assistance with cane and/or leg bracing permitted) - Presence of grip myotonia Exclusion Criteria: - Congenital DM1 - Treatment with Mexiletine within past 8 weeks - Second or third degree heart block, atrial flutter, atrial fibrillation, ventricular arrhythmias, or is receiving medication for treatment of a cardiac arrhythmia - Receiving another antimyotonia drug - Liver or kidney disease requiring ongoing treatment - Has a seizure disorder - Is pregnant or lactating - Had severe depression within 3 months or a history of suicide ideation - Has any one of the following medical conditions: uncontrolled diabetes mellitus, congestive heart failure, symptomatic cardiomyopathy, symptomatic coronary artery disease, cancer (other than skin cancer) less than five years previously, multiple sclerosis, or other serious medical illness. - Drug or alcohol abuse within 3 months - Coexistence of another neuromuscular disease - Is unable to give informed consent - Severe arthritis or other medical condition (besides DM1) that would significantly impact ambulation

Additional Information

Official title A Randomized, Placebo Controlled, Clinical Efficacy Trial of Mexiletine for Myotonic Dystrophy Type-1 (DM1)
Principal investigator Richard T. Moxley, III, MD
Description This study will provide data on the long term (6 months) safety and efficacy of mexiletine in: - improving the distance participants are able to walk in six minutes; - reducing myotonia; - improving muscle strength; - increasing lean muscle mass; - decreasing musculoskeletal pain; - improving gastrointestinal function and swallowing); - improving functional abilities; - decreasing cardiac arrhythmias; and - improving disease-specific health related quality-of-life.
Trial information was received from ClinicalTrials.gov and was last updated in February 2017.
Information provided to ClinicalTrials.gov by University of Rochester.