In a significant U-turn, FDA grants accelerated approval for DMD drug Vyondys 53

Shares of US RNA-based drug developer Sarepta Therapeutics (Nasdaq: SRPT) leapt almost 30% to $29.59 in after-hours trading yesterday, when the US Food and Drug Administration granted accelerated approval for its Vyondys 53 (golodirsen) injection to treat Duchenne muscular dystrophy (DMD) patients who have a confirmed mutation of the dystrophin gene that is amenable to exon 53 skipping.

Just four months earlier, the FDA rejected approval of the drug, which is similar to Sarepta's already marketed drug Exondys 51 (eteplirsen) that is indicated in another subset of Duchenne patients.

Sarepta said it would price Vyondys 53 "at parity" with Exondys 51, which won FDA approval in 2016. Exondys 51 costs about $300,000 per year per child. Distribution of the drug will start immediately, the company said. SVB Leerink Research analysts have previously estimated the drugs could generate sales of $1.7 billion by 2024.