FDA approves Viltepso for Duchenne muscular dystrophy.- NS Pharma/Nippon Shinyaku

The FDA has granted accelerated approval to Viltepso (viltolarsen) injection, from NS Pharma/Nippon Shinyaku, 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. Approximately 8% of patients with DMD have a mutation that is amenable to exon 53 skipping.Viltepso was evaluated in two clinical studies with a total of 32 patients, all of whom were male and had genetically confirmed DMD. The increase in dystrophin production was established in one of those two studies, a study that included 16 DMD patients, with 8 patients receiving Viltepso at the recommended dose. In the study, dystrophin levels increased, on average, from 0.6% of normal at baseline to 5.9% of normal at week 25. The FDA concluded 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 clinical benefit of the drug has not been established. In making this decision, the FDA considered the potential risks associated with the drug, the life-threatening and debilitating nature of the disease, and the lack of available therapies. The most common side effects observed in DMD patients (pooled from the two studies) treated with 80 mg/kg once a week were: Upper respiratory tract infection, injection site reaction, cough and fever.As part of the accelerated approval process, the FDA is requiring the company to conduct a clinical trial to confirm the drug's clinical benefit. The ongoing study is designed to assess whether Viltepso improves the time to stand for DMD patients with this confirmed mutation. If the trial fails to verify clinical benefit, the FDA may initiate proceedings to withdraw approval of the drug.