Regenxbio said it cleared a key milestone in a pivotal study of its Duchenne muscular dystrophy gene therapy, generating the miniaturized muscle protein expression levels needed to support an FDA filing. The company reported that the trial met its bar in participants reaching at least 10% microdystrophin expression at week 12, with 93% of treated patients achieving the threshold (n=30). The result is intended to advance the program toward regulatory review, with a longer-term goal tied to potential availability after submission. The update follows heightened scrutiny of Duchenne gene therapy safety across the category, including liver-related concerns seen in other approaches. Regenxbio positioned its dataset as meeting “accelerated approval” expectations, but the company will still need to address any remaining safety and durability questions during the FDA process. For investors and clinicians, the milestone potentially shifts timelines for what could become a second commercial option in DMD gene therapy, potentially altering the competitive landscape for dystrophin-restoring treatments.