Generic name: denileukin diftitox [ DEN-i-LOO-kin-DIF-ti-tox ]
Brand names: Lymphir, Ontak
Drug class: Miscellaneous antineoplastics

Medically reviewed by Drugs.com on Jun 17, 2025. Written by Cerner Multum.

What is denileukin diftitox?

Denileukin diftitox is used in adults to treat cutaneous (of the skin) T-cell lymphoma after at least one other treatment did not work or stopped working.

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

Denileukin diftitox side effects

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

Some side effects may occur during the injection. Tell your medical caregiver if you feel dizzy, nauseated, light-headed, itchy, sweaty, or have a headache, chest tightness, back pain, trouble breathing, or swelling in your face.

Capillary leak syndrome is a rare but serious side effect. Call your doctor right away if you have signs of this condition: low blood pressure, stuffy or runny nose followed by tiredness, thirst, decreased urination, trouble breathing, and sudden swelling or weight gain.

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

• blurred vision, changes in clarity, sharpness, or color vision; or

• liver problems--loss of appetite, nausea, vomiting, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Your cancer treatments may be delayed, reduced, or permanently discontinued if you have certain side effects.

Common side effects of denileukin diftitox may include:

• nausea, constipation;

• rash, chills, fever;

• swelling in any part of your body;

• feeling very tired;

• bone, muscle, or joint pain; or

• abnormal blood tests.

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.

Related/similar drugs

Warnings

Denileukin diftitox can cause rare but serious side effect called capillary leak syndrome. Call your doctor or seek emergency medical attention right away you have signs of this condition: stuffy or runny nose followed by tiredness, thirst, decreased urination, trouble breathing, and sudden swelling or weight gain.

Before taking this medicine

Tell your doctor if you have or have ever had:

• vision problems; or

• liver disease.

May harm an unborn baby. Do not use if you are pregnant. Use effective birth control while using Denileukin diftitox and for at least 7 days after your last dose. Tell your doctor if you become pregnant.

Do not breastfeed while using denileukin diftitox, and for at least 7 days after your last dose.

How is denileukin diftitox given?

Your doctor will perform tests to make sure denileukin diftitox is the right treatment for you.

Denileukin diftitox is injected into a vein by a healthcare provider.

Denileukin diftitox is given in a 21-day treatment cycle. You will receive an injection only on certain days of this cycle.

After receiving an injection, you will be watched closely to make sure you do not have an allergic reaction or serious side effects.

Your healthcare provider may give other medications to help prevent an allergic reaction or serious side effects.

You may need frequent medical tests including vision exams.

Doses are based on weight. Your dose may change if you gain or lose weight.

Denileukin diftitox dosing information

Usual Adult Dose for Lymphoma:

9 mcg/kg/day or 18 mcg/kg/day by IV infusion over 30 to 60 minutes for 5 consecutive days every 21 days for 8 cycles.

Comments:
-Pre-medicate with an antihistamine and acetaminophen prior to each infusion.
-Withhold treatment if serum albumin levels are less than 3.0 g/dL.
-Discontinue for adverse infusion reactions.
-Do not administer as a bolus injection.

Use: Treatment of persistent or recurrent cutaneous T-cell lymphoma whose malignant cells express the CD25 component of the IL-2 receptor.

What happens if I miss a dose?

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

What happens if I overdose?

In a medical setting an overdose would be treated quickly.

What should I avoid while receiving denileukin diftitox?

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

What other drugs will affect denileukin diftitox?

Other drugs may affect denileukin diftitox, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Denileukin diftitox Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There are 2 for denileukin diftitox.

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.

Medical Disclaimer

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