US FDA approves viltolarsen to treat patients with Duchenne muscular dystrophy mutation

US FDA approves viltolarsen to treat patients with Duchenne muscular dystrophy mutation

Viltolarsen (Viltepso) has recently received the US FDA approval as a targeted treatment for patients with a rare Duchenne muscular dystrophy (DMD) mutation, announced NS Pharma. The intravenous (IV) drug has been approved for patients who have a confirmed mutation of the DMD gene that is amenable to exon 53 skipping.

Duchenne muscular dystrophy (DMD) is a rare genetic disorder characterised by progressive muscle deterioration and weakness. DMD occurs in approximately one out of every 3,600 male infants worldwide; in rare cases, it can affect females.

It is one of the most common type of muscular dystrophy which is caused by mutations in the DMD gene that results in an absence of dystrophin, a protein that helps keep muscle cells intact. The first symptoms are usually seen between three and five years of age and worsen over time.

The approval was based on the evaluation of viltolarsen 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 the two studies, a study that included 16 DMD patients, with 8 patients receiving viltolarsen 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 most common side effects observed in DMD patient cohort in the two studies treated with 80 mg/kg once a week included upper respiratory tract infection, injection site reaction, cough and fever.

Although kidney toxicity was not observed in the clinical studies, due to limited clinical experience with viltolarsen, the FDA has advised to monitor patients taking the drug.

Viltolarsen was approved under the FDA’s accelerated approval pathway, which provides for the approval of drugs that treat serious or life-threatening diseases and generally offer a meaningful advantage over existing treatments.

As part of the accelerated approval process, the FDA has recommended the company to conduct a clinical trial to confirm the drug’s clinical benefit. The ongoing study will be designed to assess whether viltolarsen improves the time to stand for DMD patients with the confirmed mutation, in the failure of which the approval may need to be withdrawn