Long-Term Safety and Efficacy Study of Mexiletine Hydrochloride for Patients with Myotonic Dystrophy Type 1 and Type 2

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What is this study about?

This clinical trial is focused on studying the long-term safety and effectiveness of a treatment for people with Myotonic Dystrophy types 1 and 2. Myotonic Dystrophy is a genetic disorder that affects muscle function, causing symptoms like muscle stiffness and weakness. The treatment being tested is called Mexiletine, which is taken as granules for prolonged-release oral suspension. This means the medication is designed to be released slowly in the body over time, helping to manage symptoms more effectively.

The purpose of the study is to evaluate how safe and effective Mexiletine is when used over a long period. Participants in the study will take the medication once daily. The study will monitor any side effects and how well the medication helps with symptoms like muscle stiffness. Participants will also undergo regular health checks, including physical exams and heart monitoring, to ensure their safety throughout the study.

This study is an extension of a previous study, meaning it continues to follow patients who have already been taking Mexiletine to gather more information about its long-term use. The study will last for up to 18 months, during which participants will be regularly assessed to track their progress and any changes in their condition. The goal is to provide valuable insights into the long-term management of Myotonic Dystrophy with Mexiletine.

1 joining the study

Participation begins after completing the MEX-DM-302 study. This study is an extension to evaluate the long-term safety and effectiveness of a medication called mexiletine for treating muscle stiffness in myotonic dystrophy types 1 and 2.

2 medication administration

The medication used is mexiletine granules for prolonged-release oral suspension. It is available in doses of 500 mg, 333 mg, and 167 mg.

The medication is taken once daily by mouth. The exact dosage will be determined by the study team based on individual needs.

3 treatment duration

The treatment period lasts for 26 weeks. During this time, the effects of the medication on muscle stiffness and overall health will be monitored.

4 monitoring and assessments

Regular assessments will be conducted to monitor health and the medication’s effects. These include physical exams, laboratory tests, and heart monitoring using an ECG.

Specific tests include the Handgrip Dynamometer to measure muscle strength, the Myotonia Behavior Scale, and the 10 meter Walk Test to assess mobility.

5 safety evaluations

The study will track any side effects or adverse events that occur during the treatment. This includes monitoring for any heart-related issues using a Holter monitor.

6 completion of the study

At the end of the 26-week period, a final evaluation will be conducted to assess the overall impact of the treatment on muscle stiffness and quality of life.

Who Can Join the Study?

Have a confirmed diagnosis of Myotonic Dystrophy type 1 or type 2 (DM1/DM2) through genetic testing.
Be able to understand and agree to sign an informed consent form. If under 18, a parent or legal guardian must sign, and the patient must also agree in writing.
Be able to understand what the study involves and plan to stay in the study until the end, which is 26 weeks of treatment.
Be a male or a non-pregnant female who is at least 16 years old.
Have a Body Mass Index (BMI) between 18.5 and 30, and weigh at least 45 kg. BMI is a measure of body fat based on height and weight.
If a female can have children, she must use a highly effective form of birth control during the study and for at least 7 days after the last dose of the study drug.
Have no significant heart problems, as determined by a heart specialist.
Have enough strength in the fingers to hold the handle of a device used to measure muscle stiffness, known as myotonia.
For DM1 patients only, have a Muscular Impairment Rating Scale (MIRS) score of 2, 3, or 4. This scale measures the level of muscle weakness.

Who Cannot Join the Study?

Patients who have not completed the MEX-DM-302 study.
Patients who do not have a diagnosis of Myotonic Dystrophy type 1 or type 2. Myotonic Dystrophy is a genetic disorder that affects muscle function.
Patients who are not within the specified age range for the study.
Patients who are not part of the specified clinical trial group.
Patients who are considered part of a vulnerable population that the study does not include.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country
Fondazione Policlinico Universitario Agostino Gemelli IRCCS	Rome	Italy
Hospital Universitario Y Politecnico La Fe	Valencia	Spain
Katholieke Universiteit te Leuven	Leuven	Belgium
Policlinico “Tor Vergata”, Università degli Studi di Roma TOR VERGATA	Rome	Italy

Other Sites

Site Name	City	Country
Charite Research Organisation GmbH	Berlin	Germany
Hospital Universitario 12 De Octubre	Madrid	Spain
Hospital Universitario Basurto	Bilbao	Spain
Fondazione IRCCS Ca Granda Ospedale Maggiore Policlinico	Milan	Italy
Rigshospitalet	Copenhagen	Denmark
Universitätsmedizin Göttingen	Goettingen	Germany
Cwzqsu Cfaaqvv Niud	Milan	Italy
Uielqghivtpnjfinklyui Egpat Ayr	Essen	Germany
Azuknc Uttisbcomr Hrmbmxiv	Aarhus	Denmark

Trial status

Country	Status	Recruitment Start
Belgium	Recruiting	28.02.2025
Denmark	Recruiting	28.02.2025
Germany	Not yet recruiting	28.02.2025
Italy	Recruiting	28.02.2025
Spain	Recruiting	28.02.2025

Trial locations

Investigated drugs:

Mexiletine Hydrochloride

Mexiletine PR is a medication being studied for its long-term safety and effectiveness in treating myotonia, which is a symptom of myotonic dystrophy types 1 and 2. Myotonia causes muscle stiffness and difficulty relaxing muscles after use. This study is focused on patients who have already participated in a previous study, and it aims to see how well the medication works and how safe it is when taken once daily over a longer period.

Myotonic Dystrophy Type 1 – This is a genetic disorder characterized by progressive muscle wasting and weakness. It often begins in adulthood and can affect various body systems, including the heart, eyes, and endocrine system. Individuals with this condition may experience prolonged muscle contractions, known as myotonia, which can make it difficult to relax muscles after use. Over time, muscle weakness can become more pronounced, affecting mobility and daily activities. The severity and progression of symptoms can vary widely among individuals.

Myotonic Dystrophy Type 2 – This is a genetic disorder similar to type 1 but generally has a milder presentation. It also involves muscle weakness and myotonia, but symptoms often appear later in life and progress more slowly. Muscle pain and stiffness are common, and the condition can also affect the heart and other organs. Unlike type 1, facial muscle weakness is less common, and individuals may maintain more muscle strength. The progression of symptoms can vary, with some individuals experiencing only mild effects.

Trial ID:

2024-511178-66-00

Protocol code:

MEX-DM-303

Trial Phase:

Therapeutic confirmatory (Phase III)

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Long-Term Safety and Efficacy Study of Mexiletine Hydrochloride for Patients with Myotonic Dystrophy Type 1 and Type 2

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?