For the second thought piece on Sarepta’s drug and its complex FDA approval, I will focus on the drug itself and how it is meant to work.
Eteplirsen, with the trade name Exondys51, is developed by Sarepta. Its primary indication is to treat patients with Duchenne muscular dystrophy (DMD) who have a confirmed mutation of the dystrophin gene amenable to exon 51 skipping. Exondys51 is external small DNA (antisense oligonucleotide) that is introduced to patients, that would trick the cellular machinery to restore the dystrophin mRNA reading frame, which may increase the production of a truncated, but somewhat functionable form of dystrophin.
Exondys51 recently gained the approval from FDA. During its battle to gain approval, different groups have gotten involved and stirred up quite a controversy around the drug. I think it might be interesting to dive a little deeper into understanding the controversy around Exondys51.
I will spend the next few weeks educating myself and you on this drug that showed a little bit of efficacy and how it got approval. There is plenty of articles that talk about its lack of efficacy, as supported by the disapproval from the adcomm for this drug NDA. There is also another side of this story, which patient advocacy groups get intertwined and seemingly pushed the FDA to see the “slight chance” of the drug’s ability to increase dystrophin in DMD patients.
I will focus on the efficacy part in my next article. Stay tuned!