SQY51

SQY51 is an investigational antisense oligonucleotide (ASO) drug developed for the treatment of Duchenne Muscular Dystrophy (DMD), specifically targeting patients amenable to exon 51 skipping. It is a palmitoyl-conjugated tricyclo-DNA (tc-DNA) 15-mer oligonucleotide designed to hybridize with exon 51 of the dystrophin pre-mRNA, thereby restoring an operational reading frame by inducing exon skipping during mRNA splicing. This mechanism enables the production of semi-functional dystrophin protein in a subset of DMD patients with specific genetic deletions. The drug is administered via intravenous infusion and has shown favorable preclinical safety and distribution profiles in animal models, efficiently reaching skeletal muscles, respiratory muscles, and heart tissue—key targets in DMD. SQY51 has received Orphan Drug Designation from the FDA and is currently being evaluated in phase 1/2 clinical trials under the AVANCE1 study.