Phase 12 Study Evaluating SAR446268 Gene Therapy in Participants Aged 10 to 55 Years with Non-congenital Myotonic Dystrophy Type 1

What this Trial Is About

Researchers are evaluating SAR446268, an adeno-associated viral vector-mediated gene therapy, in male and female participants aged 10 to 55 years with non-congenital myotonic dystrophy type 1 DM1. This Phase 1Phase 2 open-label, single-arm study aims to assess the safety and effectiveness of SAR446268 in reducing dystrophia myotonica protein kinase DMPK mRNA levels and improving neuromuscular function in people with DM1. Participants will receive a single intravenous infusion of SAR446268. The study consists of two parts Part A, a dose escalation phase with single ascending doses in three cohorts and an optional fourth cohort, and Part B, a dose expansion phase treating additional participants at the identified safe and effective dose. Each participants involvement lasts approximately 112 weeks, including an optional pre-screening, about 8 weeks of screening, and a 104-week follow-up period after treatment. Throughout the study, participants will undergo various assessments, including muscle biopsies to measure DMPK mRNA levels and RNA splicing index at 12 and 52 weeks post-treatment. Neuromuscular function will be evaluated using tests like the 10-meter walk-run, hand opening time for myotonia, and bilateral hand grip strength at multiple time points. Researchers will also monitor the presence of the viral vector in urine, saliva, and semen samples at intervals after administration. Safety will be tracked by recording any adverse events up to 52 weeks following therapy.

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