Participants
- 32 people with DM1 will take part in this study
- All participants will receive the investigational gene therapy (this is called an "open label" study)
Check your eligibility now & get in touch with a study center
CHECK ELIGIBILITYCheck your eligibility now & get in touch with a study center
CHECK ELIGIBILITYCheck your eligibility now & get in touch with a study center
CHECK ELIGIBILITYCheck your eligibility now & get in touch with a study center
CHECK ELIGIBILITYCheck your eligibility now & get in touch with a study center
CHECK ELIGIBILITYWhat is Myotonic Dystrophy Type 1?
Myotonic Dystrophy Type 1, often called DM1, is a rare disease that runs in families. DM1 occurs due to a variation in the Myotonic Dystrophy Protein Kinase (DMPK) gene.
DM1 affects the muscles and many organs in the body. Right now, there is no treatment that can cure DM1. However, some therapies can help manage symptoms and improve quality of life.
What is the study medication?
The study medication is an investigational gene therapy, which is still being tested so it's not yet available for general use.
This is an early study (called a Phase 1/ Phase 2 study), therefore it will be the first time this investigational gene therapy is given to humans. In this study, you will receive the medication through a one-time IV (into the vein) infusion.
What is the purpose of the study?
The study will help determine if the investigational gene therapy is safe and works. The study team will run different tests to measure how well the medication works at improving muscle function.
Study Details
Duration & Visits
- After receiving the investigational gene therapy, you will be monitored by your study doctor for about 2 years (110 weeks) with 22 clinic visits
- After completing the main study, you may join an additional 3-year long term study
What can you expect during the study?
At your appointments, the following may be reviewed:
Physical exam
General appearance, cardiovascular and neurological exams, height, weight, vital signs
Muscle biopsy
A small piece of tissue taken from the front of your shin muscle using a needle to perform genetic testing
Blood and urine testing
- Blood tests for organ function, infection and DMPK genetic testing
- Urine testing for kidney function and pregnancy (females only)
ECG and Holter device
- Measure heart rhythm using electrodes
- Measure of heart rhythm over 72 hours (3 days) continuously
Imaging
- Echocardiograph of the heart
- Ultrasound of the organs in the abdomen
- Chest x-ray of the heart and lungs
Spirometry
Breathing test
Walk-run testing
Hand grip strength
Video based hand opening test
Polysomnography
Sleep study to diagnose sleep disorders
Health questionnaires
FAQs - frequently asked questions:
Is there a cost to participate?
Is there a cost to participate?
There is no cost to participate. All study-related exams, study-related medications and study-related medical care are provided. There is no insurance required to take part in this study. You may be compensated for time and travel.
Find a site near you
Am I Eligible?
Sanofi believes that everyone should have the opportunity to take part in clinical trials. It is important to include people who have been historically under-represented in clinical trials. Sanofi is committed to inclusivity in our studies.
If you are interested in learning more about this study, we encourage you to complete this brief questionnaire to help determine if you may qualify to participate and be referred to a site recruiting in your area for further evaluation.
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Version 1.0, Approved 1/2026
Intended for US Audiences Only. The investigational study drug is not approved by health authorities such as the US Food and Drug Administration (FDA) and is still under investigation for the treatment of Myotonic Dystrophy Type 1 so its effectiveness and safety have not been established.