Read VILTEPSO’s efficacy data and four-year,
long-term, open-label extension study


Jordan (14 years old), real VILTEPSO patient and compensated spokesperson

VILTEPSO is an exon-skipping therapy studied in boys with Duchenne muscular dystrophy (DMD)

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VILTEPSO is designed to skip exon 53 of the dystrophin pre-mRNA,* resulting in the production of a shortened dystrophin protein containing essential functional portions.

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Exon skipping is designed to correct an out-of-frame variant and enables the expression of a shorter dystrophin protein.

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VILTEPSO increased dystrophin levels in 100% of patients during clinical trials as measured by western blot, the laboratory standard for protein detection.


Inside each muscle cell, DNA provides the genetic information to create dystrophin. The first step in this process is the formation of pre-mRNA from DNA. The pre-mRNA is further processed into mRNA, which is then translated into a protein.

Mean increase in dystrophin expression to nearly 6% of normal with VILTEPSO (80 mg/kg/wk) vs 0.6% at baseline. Please see the study detail shown on the Efficacy & Safety page.

Early diagnosis is instrumental to inform the management of progressive muscle weakness and motor function decline in patients with DMD.

Boy smiling


VILTEPSO is for DMD patients with a confirmed mutation that is amenable to exon 53 skipping

Exon skipping is a therapeutic technique that “skips over” an exon next to the deleted exon(s) in patients with DMD.
Watch the video to see how exon skipping works.

Exon deletion and exon-skipping therapy

Nearly 50 DMD gene mutations can be treated with VILTEPSO, including, but not limited to: 45-52, 47-52, 48-52, 49-52, 50-52, and 52 of the dystrophin gene.

Deletions amenable to
exon 53 skipping

Deletions Table Deletions Table

Use our tool to see who may be eligible for therapy

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VILTEPSO was granted accelerated approval from the FDA based on increased dystrophin production—a surrogate endpoint used in DMD trials to expedite the approval of therapies to fill an unmet medical need. Continued approval is contingent upon verification of clinical benefit in a confirmatory trial.


Learn about VILTEPSO’s efficacy data and the four-year, long-term, open-label extension study


VILTEPSO offers a choice of treatment location—at home or at a treatment center

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VILTEPSO is given as an 80-mg/kg
weekly intravenous infusion

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The appropriate dose of VILTEPSO is calculated based upon patient weight, at a recommended weekly dose of 80 mg/kg

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VILTEPSO is infused for 60 minutes by a healthcare professional, either at the patient’s home or at a treatment center


Determining dosing for VILTEPSO infusion

VILTEPSO is available as single-dose vials containing 250 mg/5 mL (50 mg/mL) solution. The appropriate dose is based on patient’s body weight, with the recommended dosage of VILTEPSO 80 mg/kg administered once weekly as a 60-minute intravenous infusion.

Weekly dosing chart

Only odd kg body weight provided for illustrative purposes.

Dosing Chart table headers Weekly dosing chart by weight
Dosing Chart table headers Weekly dosing chart by weight


If volume of VILTEPSO required is <100 mL, dilution in 0.9% sodium chloride for injection, USP, is required such that the total volume in the infusion bag is 100 mL. If the volume of VILTEPSO to be infused is ≥100 mL, dilution is not required.

The actual number of theoretical vials required is 15.04.

When less than 100 mL of VILTEPSO is required:


Withdraw from the 100‑mL infusion bag a volume of 0.9% sodium chloride for injection, USP, equivalent to the calculated volume of VILTEPSO solution that will be added.


Withdraw the calculated volume of VILTEPSO solution from the appropriate number of vials, and inject into the infusion bag, such that the total volume in the bag is 100 mL.

When 100 mL or more of VILTEPSO is required:

Withdraw the calculated volume of VILTEPSO solution from the appropriate number of vials, and inject into an empty infusion bag. Further dilution is not required if the volume of VILTEPSO is 100 mL or more.

After preparation, VILTEPSO infusion
should begin as soon as possible

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Infusion should begin no more than 5 hours after preparation of VILTEPSO and be completed within 6 hours of preparation (allowing for 1 hour of infusion time) if diluted solution is stored at 20°C to 26°C (68°F to 79°F).

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VILTEPSO is administered via intravenous infusion using a peripheral or central venous catheter. Flush the intravenous access line with 0.9% sodium chloride for injection, USP, after infusion. Filtration of VILTEPSO is not required.

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Do not mix other medications with VILTEPSO or infuse other medications concomitantly via the same intravenous access line.

VILTEPSO Pocket Dosing Guide

This guide serves as a quick reference for information on appropriate VILTEPSO dose and number of corresponding VILTEPSO vials, as well as corresponding volumes of saline, VILTEPSO, and total volume of VILTEPSO solution, for select patient body weights.

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Product Order Form

Complete this form and fax or mail it to NS Support to order VILTEPSO for your appropriate patients with Duchenne muscular dystrophy (DMD) who are amenable to exon 53 skipping.

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NS Pharma Goodwill Replacement Policy

Provides guidance on how to submit a request for replacement credit due to user error or technical malfunctions during the administration of VILTEPSO.

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NS Pharma Return Goods Policy

Explains the requirements for initiating a VILTEPSO product return and describes which products are eligible for credit.

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VILTEPSO is indicated 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 indication is approved under accelerated approval based on an increase in dystrophin production in skeletal muscle observed in patients treated with VILTEPSO. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

For more information about VILTEPSO, see full Prescribing Information.

Important Safety Information

  • Warnings and Precautions: Kidney toxicity was observed in animals who received viltolarsen. Although kidney toxicity was not observed in the clinical studies with VILTEPSO, the clinical experience with VILTEPSO is limited, and kidney toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. Kidney function should be monitored in patients taking VILTEPSO. Serum creatinine may not be a reliable measure of kidney function in DMD patients.
  • Serum cystatin C, urine dipstick, and urine protein-to-creatinine ratio should be measured before starting VILTEPSO. Consider also measuring glomerular filtration rate before starting VILTEPSO. During treatment, monitor urine dipstick every month, and serum cystatin C and urine protein-to-creatinine ratio every three months.
  • Urine should be free of excreted VILTEPSO for monitoring of urine protein. Obtain urine either prior to VILTEPSO infusion, or at least 48 hours after the most recent infusion. Alternatively, use a laboratory test that does not use the reagent pyrogallol red, which has the potential to generate a false positive result due to cross reaction with any VILTEPSO in the urine. If a persistent increase in serum cystatin C or proteinuria is detected, refer to a pediatric nephrologist for further evaluation.
  • Adverse Reactions: The most common adverse reactions include upper respiratory tract infection, injection site reaction, cough, and pyrexia.
  • To report an adverse event, or for general inquiries, please call NS Pharma Medical Information at 1-866-NSPHARM (1-866-677-4276).

For more information about VILTEPSO, see full Prescribing Information.