RecruitingPHASE1, PHASE2INTERVENTIONAL

A Study to Investigate the Safety, Tolerability, and Efficacy of SAR446268, an Adeno-associated Viral Vector-mediated Gene Therapy in Participants Aged 10 to 55 Years of Age With Non-congenital Myotonic Dystrophy Type 1

This study is looking into a new treatment called SAR446268, which is a type of gene therapy, for people aged 10 to 55 with myotonic dystrophy type 1 (DM1). The main goals are to check if the treatment is safe and well-tolerated. Researchers also want to see if it can help improve how muscles work in people with DM1. The treatment is given as a single injection into the vein (intravenous). The study will first test different doses to find the safest and most effective one, and then more people will receive that chosen dose. Participants will be followed for about two years to see the long-term effects of the treatment.

At a glance

Status

Recruiting

Phase

PHASE1, PHASE2

Sponsor

Sanofi

Enrolment target

Start

23 Jul 2025

Estimated completion

27 Apr 2032

Myotonic Dystrophy

What is this study about?

This study is about a new potential treatment for a genetic condition called myotonic dystrophy type 1 (often shortened to DM1). DM1 can cause muscles to weaken and tighten over time, affecting everyday activities. Scientists have developed a treatment called SAR446268, which is a type of 'gene therapy'. Gene therapy is like a very clever package that delivers new instructions to your body's cells to help them work better.

The main aim of this study is to see if SAR446268 is safe for people with DM1, and how well their bodies tolerate it. They also want to find out if this treatment can improve muscle strength and function. This is a pioneering approach, as it tries to address the root cause of DM1 by targeting specific genetic material in the body. The research team will carefully monitor participants to understand how the treatment works and what changes it might bring.

This study is divided into two main parts. First, a small group of participants will receive different doses of SAR446268 to help researchers find the safest and most effective amount (this is called 'dose escalation'). Once the best dose is found, more participants will join the study to receive that specific dose. The hope is that this new gene therapy could offer a way to improve the quality of life for people living with DM1.

Key takeaways

This study is testing a new gene therapy for myotonic dystrophy type 1 (DM1).
It aims to find out if the treatment is safe and if it helps improve muscle function.
Participants must be between 10 and 55 years old with non-congenital DM1.
The treatment is given as a single injection, and participants are followed for two years.
It's important to understand both the potential benefits and risks before deciding to join.

Who may be eligible?

To join this study, you need to have a specific form of myotonic dystrophy type 1. This means your DM1 shouldn't have been present from birth (non-congenital), and a doctor must have already confirmed your diagnosis based on your symptoms like muscle stiffness and weakness.

You also need to have a genetic test that shows a specific change in your DNA (a CTG repeat length of 50 or more in one of your genes). You should be able to walk at least 10 meters on your own, although you can use walking aids like braces if you need them. Importantly, you would need to be between 10 and 55 years old to take part.

There are also some health conditions that would prevent you from joining. For example, if you have certain heart, liver, or kidney problems, or if you need frequent help with breathing from a machine, you might not be suitable for this study. The study team will do a thorough health check to make sure it's safe for you to participate.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 10 and 55 years old?
Do you have myotonic dystrophy type 1 (DM1) that didn't start at birth?
Has a doctor confirmed your DM1 diagnosis, including muscle weakness and stiffness?
Do you have a genetic test result showing a 'CTG repeat length' of 50 or more?
Can you walk at least 10 meters (about 33 feet) on your own, with or without aids?
Do you have any significant heart, liver, or kidney problems, or need breathing support often?

Answer every question to see your result.

What does participation involve?

If you join this study, you'll first go through a screening period, which lasts about 8 weeks, to make sure you're a good fit. During this time, you'll have various checks and tests. If you meet all the requirements, you will receive a single dose of the study treatment, SAR446268, given through a vein in your arm. After receiving the treatment, you will be carefully monitored for about two years (104 weeks). This monitoring will involve regular visits to the clinic for check-ups, assessments of your muscle strength and function, and possibly further tests. The total time you'd be involved in the study, from screening to the final follow-up, would be approximately two years.

Potential risks and benefits

Participating in research always carries potential benefits and risks. The main potential benefit of this study is that the new gene therapy, SAR446268, might improve your muscle function and overall health if it proves to be safe and effective. However, it's possible it may not work for everyone, or it might not work at all. There could also be side effects from the treatment, some of which might be serious, and these will be carefully explained to you by the study team. You have the right to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (9)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

University of Florida, 2004 Mowry Road - Site Number: 8400005
Verified postcode
Gainesville, United States· Recruiting
University of South Florida - Neuromuscular Research, 13330 USF Laurel Drive - Site Number: 8400001
Verified postcode
Tampa, United States· Recruiting
Columbia University Medical Center - Neurological Institute, 710 W. 168th, 2nd floor, suite 204 - Site Number : 8400003
Verified postcode
New York, United States· Recruiting
Virginia Commonwealth University Medical Center- Site Number : 8400006
Verified postcode
Richmond, United States· Recruiting
Hospital Italiano de Buenos Aires, Juan Domingo Peron 4190 - Site Number: 0320001
Verified postcode
Buenos Aires, Argentina· Recruiting
Investigational Site Number : 0360001
Verified postcode
Brisbane, Australia· Recruiting
The Montreal Neurological Institute and Hospital, 3801 rue University - Site Number: 1240001
Verified postcode
Montreal, Canada· Recruiting
Investigational Site Number : 3760002
Verified postcode
Ramat Gan, Israel· Recruiting
Investigational Site Number : 8260002
Verified postcode
Newcastle upon Tyne, United Kingdom· Recruiting

Common questions

What is gene therapy?

Gene therapy is a treatment that aims to fix or replace faulty genes in your body's cells to help them work properly. It's like giving your body new instructions.

What is myotonic dystrophy type 1 (DM1)?

DM1 is a genetic condition that causes muscles to become weak and not relax properly. It can affect many parts of the body.

How will the treatment be given?

The treatment, SAR446268, will be given as a single injection into a vein in your arm.

How long will I be in the study?

From start to finish, including check-ups before treatment and follow-up afterwards, you would be involved for about two years.

Can I leave the study if I change my mind?

Yes, you can choose to leave the study at any time, and it won't affect any of your other medical care.

How to find out more

Trial Transparency email recommended (Toll free for US & Canada)

contact-us@sanofi.com 800-633-1610 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.