FDA Approves Vitolarsen for Duchenne Muscular Dystrophy Mutation

Vitolarsen is the second FDA-approved targeted treatment for patients with Duchenne muscular dystrophy who have a confirmed mutation of the gene that is amenable to exon 53 skipping.

Officials from the FDA have granted accelerated approval to vitolarsen (Viltepso, NS Pharma Inc) injection for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene that is amenable to exon 53 skipping. This is the second FDA-approved targeted treatment for patients with this type of mutation, according to a press release.

The approval is based on 2 clinical studies with a total of 32 patients, all of whom were male and had genetically confirmed DMD. One of the studies, which established an increase in dystrophin production, included 16 patients with DMD, of whom 8 patients received vitolarsen at the recommended dose. This study found that dystrophin levels increased from 0.6% of normal at baseline to 5.9% of normal at week 25, according to the press release.

The FDA found that the applicant’s data demonstrated an increase in dystrophin production that is reasonably likely to predict clinical benefit in patients with DMD who have a confirmed mutation of the dystrophin gene amenable to exon 53 skipping.

A clinicial benefit of the drug has not been established, according to the FDA. The most common adverse effects observed in in patients with DMD in the 2 observed studies treated with 80 mg/kg once a week were upper respiratory tract infection, injection site reaction, cough, and fever.

REFERENCE

FDA approves targeted treatment for rare Duchenne muscular dystrophy mutation. FDA. https://www.fda.gov/news-events/press-announcements/fda-approves-targeted-treatment-rare-duchenne-muscular-dystrophy-mutation. Published August 12, 2020. Accessed August 13, 2020.