SPOT-mRNA03

**SPOT-mRNA03** is an investigational gene therapy developed by Shanghai Siponuoyin Biotechnology Co., Ltd. for Duchenne muscular dystrophy (DMD). It consists of muscle-targeted extracellular vesicles (EVs) loaded with full-length dystrophin mRNA, with targeting conferred by molecular peptides on the EV membrane. Administered via intravenous infusion, it aims to deliver dystrophin mRNA to skeletal muscle, enabling transient dystrophin protein expression to address the underlying dystrophin deficiency in DMD without genomic integration. Currently in an early Phase 1 pilot study (NCT07188012) evaluating safety, tolerability, dystrophin mRNA/protein expression, and immunogenicity in ambulatory boys aged 2-6 years, involving 8 doses over 4 weeks with immunosuppressive pretreatment.