Vyondys 53 Approved for Duchenne Muscular Dystrophy

December 12, 2019 – The U.S. FDA has approved Vyondys 53TM (golodirsen) injection, manufactured by Sarepta Pharmaceuticals, to treat Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene amenable to exon 53 skipping. Approximately 8% of DMD patients are eligible for treatment under this indication.

The most common form of muscular dystrophy, DMD affects males almost exclusively and occurs in about one out of every 3,600 male births. DMD typically manifests when patients are between three and five years of age. A genetic mutation causes a lack of dystrophin, a protein necessary for the body to maintain healthy muscle cells. This leads to muscle deterioration and weakness that worsens over time. Patients frequently require a wheelchair by their teens, and the disease is often fatal by the time a patient reaches their 20s or 30s, though severity of DMD and patient life expectancy can vary.

Vyondys 53 received accelerated approval based on a clinical study in which patients who received the drug experienced an increase in dystrophin levels. On average, dystrophin levels increased from 0.10% of normal at baseline to 1.02% of normal after at least 48 weeks of treatment with Vyondys 53. Recommended dosing is 30mg/kg of body weight administered via intravenous (IV) infusion over the course of 35-60 minutes once a week.

Because accelerated approval was granted, the FDA requires further clinical trial to confirm the drug's clinical benefit. Failure to verify clinical benefit may cause Vyondys 53 to lose FDA approval. Sarepta has launched the product at a wholesale acquisition cost (WAC) of $1,600 per 100mg vial.