Casimersen is used to treat Duchenne muscular dystrophy in adults and children who have a certain gene mutation. Your doctor will test you for this gene mutation.

Casimersen was approved by the US Food and Drug Administration (FDA) on an "accelerated" basis. In clinical studies, some people responded to casimersen, but further studies are needed.

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

Before using casimersen tell your doctor about all your medical conditions or allergies, all medicines you use, and if you are pregnant or breastfeeding.

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely using casimersen.

Casimersen is given as an infusion into a vein, usually once per week. A healthcare provider will give you this injection.

casimersen must be given slowly, and the infusion can take 35 to 60 minutes to complete.

Your kidney function may need to be checked while you are using this medicine.

Casimersen doses are based on weight. Your dose needs may change if you gain or lose weight.

Usual Adult Dose for Muscular Dystrophy:

30 mg/kg via IV infusion once a week

Comments:
-This drug has been approved under an accelerated approval based on an increase in dystrophin production in skeletal muscle; continued approval may be contingent upon verification of a clinical benefit in confirmatory trials.

Use: For the treatment of DMD in patients who have a confirmed mutation of the DMD gene that is amenable to exon 45 skipping.

Usual Pediatric Dose for Muscular Dystrophy:

30 mg/kg via IV infusion once a week

Comments:
-This drug has been approved under an accelerated approval based on an increase in dystrophin production in skeletal muscle; continued approval may be contingent upon verification of a clinical benefit in confirmatory trials.

Use: For the treatment of DMD in patients who have a confirmed mutation of the DMD gene that is amenable to exon 45 skipping.

Tell your doctor if you have ever had kidney problems.

Tell your doctor if you are pregnant or breastfeeding.

Call your doctor for instructions if you miss an appointment for your casimersen injection.

Since casimersen is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

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

Get emergency medical help if you have signs of an allergic reaction: hives, itching, rash, blistering or peeling; fever; difficult breathing; swelling of your face, lips, tongue, or throat.

Casimersen may cause serious side effects. Call your doctor at once if you have:

• pink, brown, or red urine;

• foamy urine; or

• swelling in your face, hands, feet, or stomach.

Common side effects of casimersen may include:

• headache;

• fever;

• joint pain;

• cough; or

• cold symptoms such as stuffy nose, sneezing, sore throat.

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.

Other drugs may affect casimersen, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.