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What is Viltepso's mechanism of action?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Dec 19, 2022.

Official answer


Key Points

  • Viltepso's mechanism of action is to “hide” exon 53, causing cells to bypass this exon and permitting the remaining exons (a portion of a gene) to fit together properly. This allows the body to form a shortened version of the dystrophin protein.
  • Viltepso (viltolarsen) injection helps the body to make dystrophin, a protein found in muscle cells. Dystrophin helps to strengthen and protect muscles.
  • Viltepso is approved to be used in patients who have a confirmed mutation of the DMD gene that is amenable to exon 53 skipping. When exons are missing, cells do not have the proper instructions to make dystrophin, which leads to a type of muscle damage that causes DMD.

Duchenne muscular dystrophy (DMD) is caused by a genetic mutation to the dystrophin gene that results in missing exons (a portion of the gene). Patients with a confirmed mutation of the DMD gene that is amenable to exon 53 skipping might be candidates for Viltepso treatment.

This use received FDA accelerated approval in August 2020 based on an increase in dystrophin production in skeletal muscle observed in patients treated with Viltepso. Continued approval for this use may depend upon benefits proven in a clinical research study.

If you or your child has signs or symptoms of DMD, your doctor may order a simple blood test to confirm the diagnosis. Most patients do not need a muscle biopsy and only undergo blood testing. Genetic testing is a personal decision and one that you should discuss with your doctor. About 8% of patients with DMD have exon 53 mutations that may be responsive to Viltepso treatment.

Can Viltepso be given at home?

Viltepso is given as an intravenous (IV) infusion into a vein once a week. Viltepso can be given by a healthcare professional at your home or at a treatment center. The infusion lasts about 60 minutes. The dose is based on the body weight of the patient.

Common side effects with Viltepso included upper respiratory tract infections, injection site reactions, cough, and fever. These side effects occurred in at least 15 of every 100 patients (15% of patients). Your doctor will monitor your child’s kidney function as Viltepso can cause kidney damage.

This is not all the information you need to know about Viltepso (viltolarsen) injection for safe and effective use. Review the full Viltepso information here, and discuss this and any questions you have with your doctor or other health care provider.


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