Viltolarsen
Pronunciation: pronunciation varies by local usage.
- Generic name
- viltolarsen
- Brand names
- Viltepso
- Drug class
- Antisense oligonucleotide
- Form
- Injection, solution
- Route
- Intravenous infusion
- Legal status
- Prescription-only medicine
Availability and supply rules vary by country
Trade names by country: United States
Australia: · Full directory
What viltolarsen is and how it works
Viltolarsen is an antisense oligonucleotide 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; continued approval may be contingent upon verification of clinical benefit in a confirmatory trial. (1)
Viltepso is administered as a weekly intravenous infusion. Eligibility requires genetic confirmation of a DMD mutation amenable to exon 53 skipping. This is an accelerated approval based on increased dystrophin production; continued approval may depend on verification of clinical benefit in a confirmatory trial. Treatment decisions should be made in consultation with your prescriber.
Mechanism of action: how viltolarsen works
Viltolarsen is an antisense oligonucleotide. (1)
What viltolarsen is used for
Duchenne muscular dystrophy (exon 53 skipping amenable)
Viltolarsen 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 under accelerated approval based on an increase in dystrophin production in skeletal muscle. Continued approval may be conditional on verification of clinical benefit in a confirmatory trial. (1)
Before taking viltolarsen
Do not take / not appropriate for
- The US prescribing information does not list any contraindications for viltolarsen. Viltepso is indicated specifically for patients with a confirmed mutation of the DMD gene that is amenable to exon 53 skipping. (all indications) (1)
Tell your clinician about
- Any kidney problems or symptoms, as regular renal monitoring is required.
- Pregnancy, plans for pregnancy, or breastfeeding, because there are no safety data.
- All other medicines you are taking, even though viltolarsen has a low potential for drug interactions.
How to take viltolarsen
- Viltolarsen is administered once weekly as an intravenous infusion over 60 minutes.
- The recommended dose is 80 milligrams per kilogram of body weight.
- If the infusion volume is less than 100 mL, the infusion must be diluted with 0.9% Sodium Chloride Injection. The infusion should be started within 5 hours of preparation and completed within 6 hours.
- Do not change the dose, frequency, or infusion duration without your healthcare provider's instruction.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
Contact your healthcare provider for guidance; do not alter the infusion schedule yourself.
Overdose
If an overdose is suspected, seek medical attention urgently.
Side effects
The most common adverse reactions (occurring in ≥10% of patients at the recommended 80 mg/kg dose) are upper respiratory tract infection, injection site reaction, cough, pyrexia, contusion, arthralgia, diarrhea, vomiting, and abdominal pain. Renal toxicity is a potential safety concern based on animal studies, although no cases have been detected in limited clinical experience.
Upper respiratory tract infection (63%)
What to do: Tell your treatment team if the infection is severe or persistent. (1)
Injection site reaction (25%)
What to do: Mention to your doctor if the reaction is bothersome, worsening, or not resolving. (1)
Cough (19%)
What to notice: New or worsening cough.
What to do: Report if persistent. (1)
Fever (pyrexia) (19%)
What to notice: Elevated body temperature.
What to do: Contact your doctor for guidance if this occurs. (1)
Gastrointestinal effects: diarrhea (13%), vomiting (13%), abdominal pain (13%)
What to notice: Digestive disturbances.
What to do: Inform your healthcare provider if these become severe or persistent. (1)
Musculoskeletal effects: arthralgia (13%), contusion (13%)
What to notice: Joint pain or bruising.
What to do: Discuss with your prescribing team if these are bothersome or persistent. (1)
Signs of possible renal toxicity
What to do: Contact your healthcare provider promptly for assessment. Your treatment team monitors kidney function with cystatin C and urine tests during treatment. (1)
Serious warnings
Renal toxicity (potential risk based on animal data) — warning
Symptoms: The label identifies persistent elevation of cystatin C or proteinuria as laboratory findings of concern.
Action: Your healthcare team will monitor kidney function regularly with cystatin C and urine tests. If new symptoms arise, contact them promptly. Persistent test abnormalities may lead to referral to a kidney specialist. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Other medicines | In vitro studies suggest viltolarsen has a low potential for drug-drug interactions. It did not inhibit or induce cytochrome P450 enzymes and is not a substrate of tested drug transporters. | As a general safety practice not specific to this label finding, it is still advisable to give your doctor and pharmacist a complete list of all medications, including over-the-counter products and supplements. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Children and adolescents
Viltepso is indicated for Duchenne muscular dystrophy patients with a confirmed mutation of the DMD gene amenable to exon 53 skipping. (1)
Pregnancy
There are no human or animal data on the use of viltolarsen in pregnancy. Discuss any treatment questions with your doctor, who can advise on the appropriate approach. (1)
Breastfeeding
It is unknown whether viltolarsen passes into human milk, affects the breastfed infant, or affects milk production. A decision about breastfeeding should be made together with your healthcare provider. (1)
Renal impairment
All patients receiving viltolarsen have specified baseline and ongoing renal monitoring (see Monitoring section). (1)
Monitoring
Before starting
- Confirm the DMD diagnosis and that the mutation is amenable to exon 53 skipping.
- Measure serum cystatin C, urine dipstick, and urine protein-to-creatinine ratio; consider measuring glomerular filtration rate.
During treatment
- Perform monthly urine dipstick testing.
- Obtain serum cystatin C and a quantitative proteinuria assessment (e.g., urine protein-to-creatinine ratio) quarterly.
- If persistent elevations of cystatin C or proteinuria are detected, consider referral to a pediatric nephrologist.
- Monitor for adverse reactions.
Storage
Follow the specific guidance on the product label and pharmacy information.
Professional information
Clinician-facing context only. Always refer to the most current prescribing information and local guidelines.
United States
Indication: Duchenne muscular dystrophy (exon 53 skipping)
Dose summary: 80 mg/kg once weekly, administered as an intravenous infusion over 60 minutes. If the total infusion volume is less than 100 mL, dilute with 0.9% Sodium Chloride Injection. Start infusion within 5 hours of preparation; complete within 6 hours.
Renal context: Viltolarsen has not been studied in renal impairment. It is mostly excreted unchanged in urine, so renal impairment may increase exposure. Because Duchenne muscular dystrophy reduces skeletal muscle mass, creatinine is an unreliable measure of renal function, and the label states no specific dosage adjustment can be recommended for DMD patients with renal impairment; close monitoring is required. Measure serum cystatin C, urine dipstick and urine protein-to-creatinine ratio before starting; then urine dipstick monthly and serum cystatin C plus urine protein-to-creatinine ratio every three months. (1)
Hepatic guidance
The label has no hepatic-impairment section. Clinical pharmacology states that hepatic metabolism does not contribute to the elimination of viltolarsen.
Frequently asked questions
What is Viltepso (viltolarsen) used for?
Viltepso is used to treat Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene that is amenable to exon 53 skipping. It is given once weekly by IV infusion. (1)
How is Viltepso administered?
It is given as an intravenous infusion over 60 minutes. The dose is based on body weight (80 mg per kg) and is administered once weekly. (1)
What are the possible side effects of Viltepso?
The most common side effects include upper respiratory infections, injection site reactions, cough, fever, bruising, joint pain, diarrhea, vomiting, and stomach pain. Kidney function is monitored closely because of a potential risk seen in animal studies. (1)
Does Viltepso cure Duchenne muscular dystrophy?
Viltepso is approved based on an increase in dystrophin production in skeletal muscle observed in treated patients; long-term clinical benefit has not yet been confirmed, and continued approval may depend on a confirmatory trial. (1)
What is the mechanism of action of viltolarsen?
Viltolarsen is an antisense oligonucleotide. (1)
What is the generic name of Viltolarsen?
The generic name is viltolarsen. It is sold under brand names including Viltepso. (1)
What class of drug is viltolarsen?
Viltolarsen is classed as: Antisense oligonucleotide. (1)
References
- VILTEPSO (viltolarsen) injection, solution — prescribing informationU.S. Food and Drug Administration · United States · accessed 2026-08-05 · source 1
- Viltepso — FDA approval record (Drugs@FDA NDA212154)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 2
- viltolarsen — RxNorm normalized drug concept (RXCUI 2389840)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 3
Brand names by country
Single-ingredient viltolarsen names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Viltepso250 mg · ns pharma, inc.