Chatter about a potential new drug application (NDA) filing for golodirsen (SRP-4053) started as soon as Sarepta Therapeutics Inc. reported that the phase I/II study (4053-101) of the exon 53 skipping candidate achieved statistical significance on its primary and secondary biological endpoints in boys with confirmed deletions of the gene, one of several associated with Duchenne muscular dystrophy (DMD).