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Exondys 51

Generic name: eteplirsene-TEP-lir-sen ]
Drug class: Miscellaneous uncategorized agents

Medically reviewed by on Nov 7, 2022. Written by Cerner Multum.

What is Exondys 51?

Exondys 51 works by helping the body produce a protein called dystrophin. Dystrophin is a protein that helps stabilize the structure of muscle tissue and is necessary for proper muscle development and function. Without dystrophin, muscle fibers can become weak and easily damaged. This can affect voluntary movement such as walking.

Children with Duchenne muscular dystrophy have a mutation of a gene that would normally cause the body to produce dystrophin.

Exondys 51 is used in children with Duchenne muscular dystrophy (DMD). This medicine is not a cure for DMD, but Exondys 51 may lessen muscle weakness and muscle wasting caused by this disease.

Exondys 51 was approved by the US Food and Drug Administration (FDA) on an "accelerated" basis. In clinical studies, some children responded to this medicine. However, further studies are needed to determine if this medicine is generally effective in treating DMD.

Exondys 51 may also be used for purposes not listed in this medication guide.


Before your child receives Exondys 51, tell the doctor about all your child's medical conditions or allergies, and all the medicines the child uses.

Before taking this medicine

Tell your child's doctor if any prior Exondys 51 injections caused a severe allergic reaction in your child.

Before your child receives Exondys 51, tell the doctor about all your child's medical conditions or allergies, and all the medicines the child uses.

Although Exondys 51 has been used mainly in children, it is not known whether Exondys 51 could be harmful if used during pregnancy or while nursing.

How is Exondys 51 given?

Exondys 51 is given as an infusion into a vein. A healthcare provider will give you this injection.

To make the injection more comfortable, a numbing medicine may be applied to the skin area where the IV needle will be placed.

Exondys 51 is given once per week. This medicine must be injected slowly, and the infusion can take up to 1 hour to complete.

Tell your caregivers if you feel itchy, warm, light-headed, or have chest tightness or trouble breathing when Exondys 51 is injected.

Tell your doctor if your child has any changes in weight. Exondys 51 doses are based on weight, and any changes may affect the dose.

What happens if I miss a dose?

Call your child's doctor for instructions if you miss an appointment for your child's Exondys 51.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while receiving Exondys 51?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Exondys 51 side effects

Get emergency medical help if your child has signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Common side effects of Exondys 51 may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Exondys 51?

Other drugs may affect Exondys 51, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your child's healthcare providers about all medicines the child uses now, and any medicine the child starts or stops using.

Popular FAQ

Exondys 51 is not technically gene therapy, but it does treat people with Duchenne muscular dystrophy who have a confirmed genetic mutation in their dystrophin gene which means they are unable to make the protein dystrophin. Dystrophin is needed for muscle repair. Without it, muscle cells become damaged and weakened over time, which can affect voluntary movement, such as walking. Continue reading

Exondys 51 can only be used by patients with DMD who have a confirmed mutation in their dystrophin gene that can be treated by skipping exon 51. This works out to be about 13% of people with DMD. Continue reading

There is currently no specific age range specified for using Exondys 51, but a two-part Phase 3 study scheduled to run until 2026 has recruited boys and young men aged 4 though 21 who meet the study criteria. Previous studies have only investigated boys up to age 19 years. Symptoms of Duchenne muscular dystrophy (DMD) usually appear between 3 and 5 years of age and the condition primarily affects boys at a rate of about 1 in every 3,600 male infants born. If you have an older child, the best thing you can do is talk to your doctor about Exondys 51 treatment. Continue reading

Exondys 51 is administered once a week as a 35 to 60-minute intravenous infusion by your healthcare provider. The correct dosage of Exondys 51 is drawn up and then diluted in an infusion bag containing 0.9% sodium chloride to make a total volume of 100-150 mL. The diluted solution is then administered into one of your veins via an in-line 0.2-micron filter.
  Continue reading

The new drugs approved by the FDA for the treatment of Duchenne Muscular Dystrophy (DMD) are Amondys 45 (casimersen), Viltepso (viltolarsen), Vyondys 53 (golodirsen), Exondys 51 (eteplirsen), and Emflaza (deflazacort).

Duchenne muscular dystrophy (DMD) is a genetic disease that causes progressive weakness, loss of motor function and damage to skeletal and heart muscles. DMD, which has no cure, primarily affects males starting in early childhood, usually between 2 and 3 years of age. Continue reading

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.