AT753

**AT753** is an investigational adeno-associated virus (AAV) gene therapy developed by Astellas Gene Therapies (formerly Audentes Therapeutics) for Duchenne muscular dystrophy (DMD) patients with mutations amenable to exon 53 skipping. It utilizes a self-complementary AAV9 (scAAV9) vector to deliver modified U7 small nuclear RNAs (snRNAs) that promote skipping of exon 53 in the DMD gene, aiming to restore production of a truncated but partially functional dystrophin protein essential for muscle stability. The program was advanced to preclinical stages but terminated in 2022 based on preclinical data that did not support further development.