Clinical Efficacy Trial of Mexiletine for Myotonic Dystrophy Type 1

University of Rochester

Status and phase: Completed; Phase 2

Conditions: Myotonic Dystrophy

Treatments: Drug: Placebo; Drug: Mexiletine

Study type: Interventional

Funder types: Other

Identifiers

NCT01406873

3716

Funding Source: FDA/OOPD (Other Grant/Funding Number)

Details and patient eligibility

About

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).

Full 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.

Enrollment: 42 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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42 participants in 2 patient groups, including a placebo group

Mexiletine

Active Comparator group

Description:

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.

Treatment:

Drug: Mexiletine

Sugar pill

Placebo Comparator group

Description:

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.

Treatment:

Drug: Placebo