LATE BREAKING NEWS ORAL PRESENTATION: LBO 3 Expression of apparent full-length dystrophin in skeletal muscle in a first-in-human gene therapy trial using the scAAV9.U7-ACCA vector

Abstract

Exon duplications that cause Duchenne muscular dystrophy (DMD) are promising candidates for exon skipping therapies because skipping a single exon copy should result in wild-type transcript and full-length dystrophin expression. We developed a therapeutic exon skipping viral vector (scAAV9.U7-ACCA) comprising four copies of a modified U7snRNA containing antisense sequences targeting the splice donor (2 copies) and splice acceptor (2 copies) of the DMD exon 2, the most commonly duplicated exon. Following dose finding studies in Dup2 mice and after demonstrating lack of toxicity in non-human primates, we initiated a first-in-human clinical trial (NCT04240314).