The FDA granted accelerated approval to Viltepso (viltolarsen) to treat Duchenne muscular dystrophy patients (DMD) who have a confirmed mutation of the DMD gene amenable to exon 53 skipping, pitting it against Sarepta Therapeutics Inc.’s Vyondys (golodirsen), which was given accelerated approval last year in a controversial decision by the FDA following an agency complete response letter (CRL) highlighting safety concerns.