US-based biopharmaceutical company Sarepta Therapeutics has secured the US Food and Drug Administration (FDA) accelerated approval for its Exondys 51 (eteplirsen) as a once-weekly intravenous infusion of 30mg per kg to treat Duchenne muscular dystrophy (DMD).
Exondys 51 uses Sarepta’s patented phosphorodiamidate morpholino oligomer (PMO) chemistry and exon-skipping technology to skip exon 51 of the dystrophin gene. Exon skipping enables production of an internally truncated dystrophin protein.
It binds to exon 51 of dystrophin pre-mRNA, resulting in the removal of this exon during Messenger RNA (mRNA) processing in patients with genetic mutations that are amenable to exon 51 skipping.
FDA Center for Drug Evaluation and Research director Janet Woodcock said: “Patients with a particular type of Duchenne muscular dystrophy will now have access to an approved treatment for this rare and devastating disease.
“In rare diseases, new drug development is especially challenging due to the small numbers of people affected by each disease and the lack of medical understanding of many disorders.
“Accelerated approval makes this drug available to patients based on initial data, but we eagerly await learning more about the efficacy of this drug through a confirmatory clinical trial that the company must conduct after approval.”
DMD is a rare genetic disorder causing progressive muscle deterioration and weakness due to the absence of dystrophin, a protein which helps to keep muscle cells intact.
Exondys 51 was granted an accelerated approval on the basis of data, which suggested an increased dystrophin production in skeletal muscle.
Sarepta has been recommended by the FDA to undertake a clinical trial to test the drug’s efficacy in improving motor functions in DMD patients with a confirmed mutation of the dystrophin gene amenable to exon 51 skipping.