Elzonris is used to treat blastic plasmacytoid dendritic cell neoplasm, a rare blood and/or bone marrow cancer.

Elzonris is for use in adults and children at least 2 years old.

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

Call your doctor right away if you have signs of a serious side effect called capillary leak syndrome: stuffy or runny nose followed by tiredness or dizziness, thirst, decreased urination, trouble breathing, and sudden swelling or weight gain.

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

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

You may receive this medicine in a hospital or clinic setting to quickly treat any serious side effects.

You may be given other medications to help prevent serious side effects or an allergic reaction. Keep using these medicines for as long as your doctor has prescribed.

Elzonris is given in a 21-day treatment cycle. You may need to use the medicine only during the first 5 days of each cycle. Your doctor will determine how long to treat you with this medicine.

You may need frequent medical tests to be sure this medicine is not causing harmful effects. Your cancer treatments may be delayed or permanently discontinued based on the results.

You may need to have a negative pregnancy test 1 week before starting this treatment.

Elzonris may harm an unborn baby. Use effective birth control to prevent pregnancy while you are using Elzonris and for at least 1 week after your last dose.

Do not breastfeed while using this medicine, and for at least 1 week after your last dose.

Call your doctor for instructions if you miss an appointment for your Elzonris.

Since Elzonris 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, rash, itching; mouth sores; sudden warmth or tingly feeling; difficult breathing; swelling of your face, lips, tongue, or throat.

Capillary leak syndrome is a serious side effect of tagraxofusp. Call your doctor right away if you have a stuffy or runny nose followed by:

• tiredness or dizziness;

• thirst;

• decreased urination;

• trouble breathing; and

• sudden swelling or weight gain.

Common side effects of Elzonris may include:

• capillary leak syndrome;

• nausea;

• tiredness;

• swelling in your hands or feet;

• fever; or

• weight gain.

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 Elzonris, 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.