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Observational Study for Myotonic Dystrophy Type 1 (END-DM1)

This is an observational study called END-DM1 for people with Myotonic Dystrophy Type 1 (DM1). It aims to better understand how DM1 progresses and to find reliable ways to measure the disease (biomarkers). Researchers will look at changes in your walking ability and breathing over 24 months. They will also study specific genetic markers related to DM1. You can join if you are 18 to 70 years old and have a confirmed diagnosis of DM1. The study is funded by the FDA and plans to enroll about 700 participants. There are no treatments given in this study; you will continue to receive your usual medical care.

Study design
This is an observational study with approximately 700 adult participants. It is not testing a specific treatment, but rather observing the natural course of Myotonic Dystrophy Type 1.
What's involved
You will have study visits at the beginning, 12 months, and 24 months. Some participants may have additional visits for muscle biopsies or to complete a COVID-19 survey.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed for 24 months, with some measurements taken at 3 months for a subset of participants.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT03981575

Estab Biomarkers and Clinical Endpoints in Myotonic Dystrophy Type 1 (END-DM1)

Recruiting
Not specifiedAges 18–70Observational
Virginia Commonwealth University
~700 participants
Updated 2026-06-10 on ClinicalTrials.gov

At a glance

Recruiting sites
15 of 17 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Change in ambulation over 24 months as measured by the 10 meter walk (m/s).
Measured over 12 and 24 months
+2 more outcomes measured

Conditions

Myotonic Dystrophy 1
DM1

Explore related trials

Myotonic Dystrophy

Where it's being run

17 sites across 15 states
California2
United Kingdom2
Colorado1
Florida1
Iowa1
Kansas1
New York1
Ohio1

Study leadership

  • Nicholas Johnson, MD · PRINCIPAL_INVESTIGATOR · Virginia Commonwealth University
  • Charles Thornton, MD · PRINCIPAL_INVESTIGATOR · University of Rochester

Who to contact

Jennifer Raymond
[email protected]
804-828-6318
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Age 18 to 70 (inclusive)
Competent to provide informed consent
Clinical diagnosis of DM1 based on research criteria1 or positive genetic test
Comment: The clinical research criteria require myotonia, muscle weakness in a characteristic distribution, and history of similar findings in a first degree relative. Genetic testing confirmed the diagnosis of DM1 in \> 99% of individuals who satisfied these criteria.2

Exclusion

Symptomatic renal or liver disease, uncontrolled diabetes or thyroid disorder, or active malignancy other than skin cancer.
Current alcohol or substance abuse
Concurrent enrollment in clinical trial for DM1, or participation in trial within 6 months of entry.
Concurrent pregnancy or planned pregnancy during the course of the study.
Concurrent medical condition that would, in the opinion of the investigator or clinical evaluator, compromise performance on study measures.
Note: non-ambulatory participants are not excluded, but are limited to \<15% of enrollment.
Known CTG repeat expansion size less than 100 repeats, unless there are clear cut signs of limb weakness and muscle wasting. This is in order to obtain a muscle tissue sample in a person more severely affected with myotonic dystrophy.
Use of anticoagulant such as warfarin or a direct oral anticoagulant (e.g. dabigatran) due to the increased risk of bleeding.
Use of aspirin or non-steroidal anti-inflammatory agents should be discontinued 3 days prior to the biopsy procedure, if possible.
Platelet count \<50,000 (if known) due to the increased risk of bleeding.
History of a bleeding disorder due to the increased risk of bleeding.
Advanced wasting of tibialis anterior (TA) muscle that precludes needle muscle biopsy in order to ensure that a sample taken would be of muscle and not just fat and fascia.
Previous muscle biopsy of either TA in order to provide muscle tissue samples of non-biopsied muscles.

What this trial measures

  • Change in ambulation over 24 months as measured by the 10 meter walk (m/s).12 and 24 months

    10 meter walk will be measured (m/s)

  • Change in respiratory function over 24 months as measured by spirometry, specifically the supine forced vital capacity (FVC).12 and 24 months

    Supine forced vital capacity (% predicted)

  • Percent splicing of DM1-affected splice events3 months

    RNA sequenced of muscle biopsy samples collected at two different times will be combined and used to calculate a percent splicing index (PMI)