Sanofi’s SAR446268 Gene Therapy Receives US Fast Track Designation for Non-Congenital Myotonic Dystrophy Type 1
Tuesday, September 23, 2025
Sanofi has received Fast Track designation from the US Food and Drug Administration (FDA) for its investigational therapy SAR446268, developed for juvenile and adult non-congenital myotonic dystrophy type 1 (DM1).
SAR446268 is an adeno-associated virus (AAV) gene therapy that uses an RNA interference approach to silence the DMPK gene with a single administration. By lowering DMPK transcripts, the therapy aims to clear toxic RNA foci in muscle tissue, correct splicing defects and restore muscle function. This could help address symptoms such as progressive muscle weakness, delayed muscle relaxation (myotonia), and complications involving the heart, lungs and endocrine system.
Myotonic dystrophy type 1, also called Steinert disease, is a rare inherited disorder caused by mutations in the DMPK gene. It affects about 1 in 2,300 people worldwide and can appear at any age with varying severity. The condition leads to progressive muscle weakness, difficulty relaxing muscles and complications across multiple body systems. Severe cases may impair vital functions, with a significant impact on daily life and independence.
The designation is intended to speed up the development and review of medicines for serious conditions with limited treatment options.
The therapy is the only candidate currently in clinical development for DM1, a condition with no approved treatments. A first-in-human Phase 1/2 clinical trial (NCT06844214) is under way to assess safety, tolerability and efficacy, with the first patient expected to be enrolled by the end of 2025.
Sanofi has also secured orphan drug status for SAR446268 in both the US and EU.
Source: globenewswire.com
