Myotonic DystrophyPhase 1/2BrAAVeNCT06844214
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
A Phase 1/2 study testing SAR446268 in people with Myotonic Dystrophy, run by Sanofi at 10 sites in 6 countries.
Trial summary
This is a Phase 1/Phase 2 open-label single arm, multicenter, and multinational study with SAR446268 for treatment of male and female participants 10 to 55 years old with non-congenital myotonic dystrophy (DM) type 1 (DM1). Read more about this study
- Who is it for?
- Ages 10 to 55 years
- Conditions the study is for
- Myotonic Dystrophy
- What is being tested?
- SAR446268
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 10 sitesin 6 countries
- Study dates
- 23 Jul 2025to 27 Apr 2032
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 55 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Participants are eligible to be included in the study only if all of the following criteria apply:
- For Part A, participants must be 18 to 55 years of age inclusive, at the time of signing the informed consent.
- For Part B, participants must be as follows:
- 10 to 17 years of age inclusive, at the time of signing the informed consent or,
- 18 to 55 years of age inclusive, at the time of signing the informed consent.
- Participants with non-congenital onset DM1
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- Participants presenting with signs of DM1 including myotonia and muscle weakness, as diagnosed previously by a clinician based on medical history.
- Participants with genetic diagnosis of DM1 [cytosine-thymine-guanine (CTG) repeat length ≥50 in one allele from medical history]
- Participants who can walk independently for at least 10 meters at screening (orthoses and ankle braces allowed).
Who cannot join
- Participants are excluded from the study if any of the following criteria apply:
- Participants with neutralizing antibodies against the AAV.SAN011 capsid
- Participants with left ventricular ejection fraction <50%
- Participants with liver or biliary disease defined as having at least one of the following:
- ALT >3 x ULN and AST >3 x ULN
- Alkaline phosphatase >3 x ULN
Show all 26Show fewer
- Total bilirubin >1.5 x ULN (unless has a genetically confirmed diagnosis of Gilbert's syndrome)
- Direct bilirubin ≥1.5 x ULN
- Participants with International normalized ratio >1.5
- Participants with renal disease defined as:
- Serum creatinine >1.5 x ULN and/or estimated glomerular filtration rate <60 mL/min/1.73 m2 as determined by Chronic Kidney Disease Epidemiology Collaboration (2021) for those age ≥18 years and Bedside Schwartz Equation for those <18 years
- Participants with chronic respiratory insufficiency and on long term/hull-time ventilatory assistance requiring at least 6 hours per day for at least 21 consecutive days.
- Participants with contraindication to corticosteroid or with conditions that could worsen in the presence of corticosteroids, as determined by the Investigator.
- Participants with active hepatitis B or C infection; HBsAg (+), or HCV RNA (+), or current antiviral therapy for either.
- Participants with HBcAb (+) who are not amenable for prophylactic anti-HBV therapy or pre-emptive therapy guided by serial HBV DNA monitoring during the corticosteroids therapy.
- Participants at high risk for tuberculosis reactivation during the corticosteroids therapy as determined by the Investigator.
- Participants with a known HIV infection
- Participants with serious intercurrent illness that, in the opinion of the Investigator, would preclude participation in the study or potentially decrease survival.
- Participants with recent history of or current drug or alcohol abuse in the past 12 months prior to screening.
- Participants with history of tibialis anterior biopsy within 12 weeks from Day 1 or planning to undergo tibialis anterior biopsies during the duration of this clinical trial.
- Participants with significant developmental delay, intellectual disability, or behavioral neuropsychiatric manifestations as determined by the Investigator.
- Participants with previous systemic corticosteroids treatment at doses of >5 mg/day within 15 days of Day 1
- Participants with previous treatment with anti-myotonic medication within 15 days of Day 1
- Participants not suitable for participation, whatever the reason, as judged by the Investigator, including medical or clinical conditions, or participants potentially at risk of noncompliance to study procedures.
- Participants who have been classified as severe cardiac risk by the Investigator.
- The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.
Trial locations and contacts
10 sites in 6 countries. Contact the study team or a site near you to ask about taking part.
Trial Transparency email recommended (Toll free for US & Canada) contact
10 sites in 6 countries
United States5 sites, 5 recruiting
- Recruiting
University of Florida, 2004 Mowry Road - Site Number: 8400005
Gainesville, Florida, 32601
Melissa Lewis, 352-273-8219, melissa.lewis@peds.ufl.edu
Dr. Subramony
- Recruiting
Columbia University Medical Center - Neurological Institute, 710 W. 168th, 2nd floor, suite 204 - Site Number : 8400003
New York, New York, 10032
Jorge Cabrera, 212-305-7462, jec2273@cumc.columbia.edu
Dr. Christina Ulane
- Recruiting
Penn Medicine: University of Pennsylvania Health System- Site Number : 8400009
Philadelphia, Pennsylvania, 19104
- Recruiting
Virginia Commonwealth University Medical Center- Site Number : 8400006
Richmond, Virginia, 23298
- Recruiting
University of South Florida - Neuromuscular Research, 13330 USF Laurel Drive - Site Number: 8400001
Tampa, Florida, 33612
Sruthi Kommi Reddy, SKommiReddy@usf.edu
Dr. Tuan Vu
Argentina1 site, 1 recruiting
- Recruiting
Hospital Italiano de Buenos Aires, Juan Domingo Peron 4190 - Site Number: 0320001
Buenos Aires, 1181
Ventura Simonovich, 54 11 4959 0200, ventura.simonovich@hospitalitaliano.org.ar
Ventura Simonovich
Australia1 site, 1 recruiting
- Recruiting
Investigational Site Number : 0360001
Brisbane, Queensland, 4029
Canada1 site, 1 recruiting
- Recruiting
The Montreal Neurological Institute and Hospital, 3801 rue University - Site Number: 1240001
Montreal, Quebec, H3A 2B4
514-398-5500, nm.neurocru@mcgill.ca
Dr. Erin O'Ferrall
Israel1 site, 1 recruiting
- Recruiting
Investigational Site Number : 3760002
Ramat Gan, 5262100
United Kingdom1 site, 1 recruiting
- Recruiting
Investigational Site Number : 8260002
Newcastle upon Tyne, NE7 7DN
About this study
Official title: A Phase 1/Phase 2 Open-label Single Arm Study With Dose Escalation (Part A), and Dose Expansion (Part B) Parts to Evaluate the Safety, Tolerability, and Efficacy of SAR446268, an Adeno-associated Viral Vector-mediated Gene Therapy in Participants 10 to 55 Years Old With Non-congenital Myotonic Dystrophy Type 1
This is a Phase 1/Phase 2 open-label single arm, multicenter, and multinational study with SAR446268 for treatment of male and female participants 10 to 55 years old with non-congenital myotonic dystrophy (DM) type 1 (DM1).
The purpose of this study is to evaluate the safety and efficacy of SAR446268 in knocking down dystrophia myotonica protein kinase (DMPK) messenger ribonucleic acid (mRNA) levels and improving neuromuscular function in DM1 participants receiving a single intravenous (IV) administration of SAR446268. The study consists of a dose escalation part (Part A) during which single ascending doses of SAR446268 will be evaluated in 3 distinct cohorts and an optional fourth dose cohort. Once a safe and effective dose is identified, additional participants will be treated in Part B, the dose expansion phase of the study.
The study duration will be 112 weeks (approximately 2 years) for each participant in Parts A and B respectively and includes an optional pre-screening period, approximately 8-week screening phase and a 104-week follow-up period post-SAR446268 administration.
Read the detailed description
Each participant meeting the eligibility criteria for each of the study parts will receive a single dose administration of SAR446268.
- Conditions
- Myotonic Dystrophy
- Being tested
- SAR446268
- Medical subject headings
- Myotonic Dystrophy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SAR446268Biological
Pharmaceutical form: Solution for infusion; Route of administration: IV infusion
| Study group | Role | What they receive |
|---|---|---|
| SAR446268 | Experimental | Participants will receive a single dose of SAR446268 on Day 1 Receives: Biological: SAR446268 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Part A and Part B: Incidence of treatment-emergent adverse events (TEAEs) following SAR446268 administration
Number of TEAEs post-SAR446268 administration
Measured: Baseline to Week 52
Part B: Proportion of participants with at least 40% DMPK mRNA knockdown in muscle biopsy at Weeks 12 and 52 following SAR446268 administration
Measured: Weeks 12 and 52
Secondary outcomes (13)
Part A: Change in 10-meter walk-run test from baseline to Weeks 26 and 52 following SAR446268 administration
The 10-meter walk-run test is a mobility test that measures how fast a participant can traverse 10 meters with or without assisted devices.
Measured: Baseline to Week 26 and 52
Part A: Change in myotonia from baseline to Weeks 26 and 52 following SAR446268 administration as measured by the hand opening time (middle finger)
This test for myotonia measures how quickly a participant can open his/her hand after making a tight fist.
Measured: Baseline to Week 26 and 52
Part A: Change in bilateral hand grip test from baseline to Weeks 26 and 52 following SAR446268 administration
This test for strength of the hand muscles measures the maximum force generated by a participant's hand grip using a dynamometer.
Measured: Baseline to Week 26 and 52
Part A: Proportion of participants with at least 40% DMPK mRNA knockdown in muscle biopsy at Weeks 12 and 52 following SAR446268 administration
Measured: Weeks 12 and 52
Part A: Change in DMPK mRNA levels in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Measured: Baseline to Week 12 and 52
Part A: Change in RNA splicing index in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Measured: Baseline to Week 12 and 52
Part A: Assessment of the duration of AAV vector shedding of SAR446268 in sampling of urine, saliva, and semen at 4-week intervals following SAR446268 administration
Measured: Baseline, Weeks 4, 8, and 12
Part B: Change in 10-meter walk-run test from baseline to Weeks 26 and 52 following SAR446268 administration
The 10-meter walk-run test is a mobility test that measures how fast a participant can traverse 10 meters with or without assisted devices.
Measured: Baseline to Week 26 and 52
Part B: Change in myotonia from baseline to Weeks 26 and 52 following SAR446268 administration as measured by the hand opening time (middle finger)
This test for myotonia measures how quickly a participant can open his/her hand after making a tight fist.
Measured: Baseline to Week 26 and 52
Part B: Change in bilateral hand grip test from baseline to Weeks 26 and 52 following SAR446268 administration
This test for strength of the hand muscles measures the maximum force generated by a participant's hand grip using a dynamometer.
Measured: Baseline to Week 26 and 52
Part B: Change in DMPK mRNA knockdown in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Measured: Baseline to Week 12 and 52
Part B: Change in RNA splicing index in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Measured: Baseline to Week 12 and 52
Part B: Assessment of the duration of AAV shedding of SAR446268 in sampling of urine, saliva, and semen at 4-week intervals following SAR446268 administration
Measured: Baseline, Weeks 4, 8, and 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2025
- Study start23 Jul 2025
- Primary completion28 Feb 2029 (estimated)
- Study completion27 Apr 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Myotonic DystrophyStudies of the same condition, open and under way.
- More trials run by SanofiThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sanofi
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06844214
- Sponsor's protocol ID
- DFI17808
- Other IDs
- U1111-1290-9594
- Acronym
- BrAAVe
- Status last verified
- Sep 2026
- First submitted
- 19 Feb 2025
- Last updated
- 21 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
Study at a glance
From the registry record, last updated by the sponsor on 21 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1/Phase 2 Open-label Single Arm Study With Dose Escalation (Part A), and Dose Expansion (Part B) Parts to Evaluate the Safety, Tolerability, and Efficacy of SAR446268, an Adeno-associated Viral Vector-mediated Gene Therapy in Participants 10 to 55 Years Old With Non-congenital Myotonic Dystrophy Type 1
- ClinicalTrials.gov ID
- NCT06844214
- Acronym / sponsor ID
- BrAAVe / DFI17808
- Conditions
- Myotonic Dystrophy
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- SanofiIndustry (pharma, biotech, devices)
- Study start
- 23 Jul 2025 (actual)
- Primary completion
- 28 Feb 2029 (estimated)
- Study completion
- 27 Apr 2032 (estimated)
- First posted
- 25 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a Phase 1/Phase 2 open-label single arm, multicenter, and multinational study with SAR446268 for treatment of male and female participants 10 to 55 years old with non-congenital myotonic dystrophy (DM) type 1 (DM1).
The purpose of this study is to evaluate the safety and efficacy of SAR446268 in knocking down dystrophia myotonica protein kinase (DMPK) messenger ribonucleic acid (mRNA) levels and improving neuromuscular function in DM1 participants receiving a single intravenous (IV) administration of SAR446268. The study consists of a dose escalation part (Part A) during which single ascending doses of SAR446268 will be evaluated in 3 distinct cohorts and an optional fourth dose cohort. Once a safe and effective dose is identified, additional participants will be treated in Part B, the dose expansion phase of the study.
The study duration will be 112 weeks (approximately 2 years) for each participant in Parts A and B respectively and includes an optional pre-screening period, approximately 8-week screening phase and a 104-week follow-up period post-SAR446268 administration.
Detailed description
Each participant meeting the eligibility criteria for each of the study parts will receive a single dose administration of SAR446268.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| SAR446268 | Experimental | Biological: SAR446268Participants will receive a single dose of SAR446268 on Day 1 |
Who may qualify
- Ages
- 10 to 55 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (9 listed)
- Participants are eligible to be included in the study only if all of the following criteria apply:
- For Part A, participants must be 18 to 55 years of age inclusive, at the time of signing the informed consent.
- For Part B, participants must be as follows:
- Participants with non-congenital onset DM1
- Participants presenting with signs of DM1 including myotonia and muscle weakness, as diagnosed previously by a clinician based on medical history.
Key exclusion criteria (26 listed)
- Participants with neutralizing antibodies against the AAV.SAN011 capsid
- Participants with left ventricular ejection fraction <50%
- Participants with liver or biliary disease defined as having at least one of the following:
- Participants with renal disease defined as:
- Participants with chronic respiratory insufficiency and on long term/hull-time ventilatory assistance requiring at least 6 hours per day for at least 21 consecutive days.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SAR446268Pharmaceutical form: Solution for infusion; Route of administration: IV infusion | Biological | SAR446268 |
Primary outcome
Part A and Part B: Incidence of treatment-emergent adverse events (TEAEs) following SAR446268 administration
Time frame: Baseline to Week 52
Number of TEAEs post-SAR446268 administration
Part B: Proportion of participants with at least 40% DMPK mRNA knockdown in muscle biopsy at Weeks 12 and 52 following SAR446268 administration
Time frame: Weeks 12 and 52
13 secondary outcomes
Part A: Change in 10-meter walk-run test from baseline to Weeks 26 and 52 following SAR446268 administration
Time frame: Baseline to Week 26 and 52
Part A: Change in myotonia from baseline to Weeks 26 and 52 following SAR446268 administration as measured by the hand opening time (middle finger)
Time frame: Baseline to Week 26 and 52
Part A: Change in bilateral hand grip test from baseline to Weeks 26 and 52 following SAR446268 administration
Time frame: Baseline to Week 26 and 52
Part A: Proportion of participants with at least 40% DMPK mRNA knockdown in muscle biopsy at Weeks 12 and 52 following SAR446268 administration
Time frame: Weeks 12 and 52
Part A: Change in DMPK mRNA levels in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Time frame: Baseline to Week 12 and 52
Part A: Change in RNA splicing index in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Time frame: Baseline to Week 12 and 52
Part A: Assessment of the duration of AAV vector shedding of SAR446268 in sampling of urine, saliva, and semen at 4-week intervals following SAR446268 administration
Time frame: Baseline, Weeks 4, 8, and 12
Part B: Change in 10-meter walk-run test from baseline to Weeks 26 and 52 following SAR446268 administration
Time frame: Baseline to Week 26 and 52
Part B: Change in myotonia from baseline to Weeks 26 and 52 following SAR446268 administration as measured by the hand opening time (middle finger)
Time frame: Baseline to Week 26 and 52
Part B: Change in bilateral hand grip test from baseline to Weeks 26 and 52 following SAR446268 administration
Time frame: Baseline to Week 26 and 52
Part B: Change in DMPK mRNA knockdown in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Time frame: Baseline to Week 12 and 52
Part B: Change in RNA splicing index in muscle biopsy from baseline to Weeks 12 and 52 following SAR446268 administration
Time frame: Baseline to Week 12 and 52
Part B: Assessment of the duration of AAV shedding of SAR446268 in sampling of urine, saliva, and semen at 4-week intervals following SAR446268 administration
Time frame: Baseline, Weeks 4, 8, and 12
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Sep 2026.
- DFI17808 Plain Language Results SummaryLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Trial Transparency email recommended (Toll free for US & Canada) contact
10 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing SAR446268 in people with Myotonic Dystrophy, run by Sanofi at 10 sites in 6 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 26 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 10 sites in United States, Argentina, Australia, Canada, Israel and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Trial Transparency email recommended (Toll free for US & Canada) (800-633-1610 ext. option 6, contact-us@sanofi.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Part A and Part B: Incidence of treatment-emergent adverse events (TEAEs) following SAR446268 administration (time frame: Baseline to Week 52). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Sep 2026.