Gilteritinib is used to treat acute myeloid leukemia (AML) in adults with an abnormal FLT3 gene. Your doctor will test you for this gene.

Gilteritinib is given after other cancer treatments did not work or have stopped working.

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

Gilteritinib can cause a condition called differentiation syndrome, which affects blood cells and can be fatal if not treated. This condition may occur within 2 days to 3 months after you start taking gilteritinib.

Seek medical help right away if you have symptoms of differentiation syndrome: fever, cough, trouble breathing, bone pain, rapid weight gain, or swelling in your arms, legs, underarms, groin, or neck.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

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

Gilteritinib is usually given once per day. Take this medicine with a full glass of water, at the same time each day.

You may take gilteritinib with or without food.

Do not crush, chew, or break a gilteritinib tablet. Swallow it whole.

It may take several months before you receive the full benefit of taking gilteritinib. Your doctor will determine how long to treat you with this medicine.

Do not change your dose or stop taking gilteritinib without your doctor's advice.

Store this medicine in the original container at room temperature, away from moisture and heat.

Usual Adult Dose for Acute Myeloid Leukemia:

120 mg orally once a day until disease progression or unacceptable toxicity

Comments:
-Response may be delayed. In the absence of disease progression or unacceptable toxicity, patients should be treated for a minimum of 6 months to allow time for a clinical response.
-Select patients for the treatment of AML with this drug based on the presence of FLT3 mutations in the blood or bone marrow.

Use: For the treatment of adult patients who have relapsed or refractory acute myeloid leukemia (AML) with an FMS-like tyrosine kinase 3 (FLT3) mutation.

You should not use gilteritinib if you are allergic to it.

Tell your doctor if you have ever had:

• heart problems;

• long QT syndrome (in you or a family member); or

• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood).

Before you take gilteritinib, your heart function may need to be checked using an electrocardiograph or ECG (sometimes called an EKG).

Gilteritinib can harm an unborn baby or cause birth defects if the mother or the father is using this medicine.

• If you are a woman, do not use gilteritinib if you are pregnant. You may need to have a negative pregnancy test before starting this treatment. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 6 months after your last dose.

• If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 4 months after your last dose.

• Tell your doctor right away if a pregnancy occurs while either the mother or the father is using gilteritinib.

Do not breastfeed while using this medicine, and for at least 2 months after your last dose.

Take the missed dose on the same day you remember it. Skip the missed dose if your next dose is due in less than 12 hours. Do not use two doses within a 12-hour period.

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

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

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; difficult breathing; swelling of your face, lips, tongue, or throat.

Gilteritinib can cause a condition called differentiation syndrome, which affects blood cells and can be fatal if not treated. This condition may occur within 2 days to 3 months after you start taking gilteritinib.

Seek medical help right away if you have symptoms of differentiation syndrome:

• fever, cough, trouble breathing;

• bone pain;

• rapid weight gain; or

• swelling in your arms, legs, underarms, groin, or neck.

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

• headache, confusion, change in mental status, vision loss, seizure (convulsions);

• fever, chills, cough with mucus, chest pain;

• flu symptoms, mouth and throat ulcers;

• severe pain in your upper stomach spreading to your back, nausea and vomiting;

• a light-headed feeling, like you might pass out; or

• fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out).

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

Common side effects of gilteritinib may include:

• nausea, vomiting, diarrhea, constipation;

• pain or sores in the mouth or throat;

• cough, shortness of breath;

• headache, dizziness;

• eye problems;

• muscle or joint pain;

• low blood pressure;

• swelling of your arms or legs;

• fever, tiredness;

• decreased urination;

• rash; or

• abnormal liver function 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.

Other drugs may affect gilteritinib, 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.

Keep all appointments with your doctor and the laboratory. Your doctor will order a lab test before you begin your treatment to see whether your cancer can be treated with gilteritinib. Your doctor will also order certain lab tests before and during your treatment to check your body's response to gilteritinib. Your doctor may also order an electrocardiogram (ECG; test that measures the electrical activity in the heart) before and during your treatment.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.