Moxetumomab pasudotox is used to treat adults with hairy cell leukemia.

Moxetumomab pasudotox is given after at least two other cancer treatments did not work or have stopped working.

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

Moxetumomab pasudotox can damage your kidneys, especially if you already have kidney disease or if you are 65 years of age or older. Get emergency medical help if you have: unusual bruising or bleeding, fever, confusion, tiredness or irritability, stomach pain, vomiting, dark urine, fast heartbeats, and little or no urination.

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

This medicine must be given slowly, and the infusion can take about 30 minutes to complete.

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

Moxetumomab pasudotox is given in a 28-day treatment cycle. You may need to use the medicine only during the first week of each cycle. You may receive up to 6 treatment cycles. Your doctor will determine how long to treat you with this medicine.

During the first 8 days of each treatment cycle, drink up to 12 full 8-ounce glasses of water, milk, or juice every 24 hours.

Usual Adult Dose for Hairy Cell Leukemia:

0.04 mg/kg IV over 30 minutes on Days 1, 3, and 5 of each 28-day cycle for a maximum of 6 cycles, disease progression, or unacceptable toxicity

Recommended Concomitant Treatment:
-Hydrate with 1 L of isotonic solution (e.g., 5% dextrose injection, and 0.45% or 0.9% sodium chloride injection) over 2 to 4 hours before and after each infusion. -Administer 0.5 L to patients under 50 kg.
-Advise patients to hydrate with up to 3 L of oral fluids (e.g., water, milk, or juice) per 24 hours on Days 1 through 8 of each 28-day cycle. In patients under 50 kg, up to 2 L per 24 hours is recommended.

Comments:
-Premedicate 30 to 90 minutes prior to each infusion with and antihistamine (e.g., hydroxyzine or diphenhydramine), acetaminophen, and a histamine-2 receptor antagonist (e.g., ranitidine, famotidine, or cimetidine).
-Consider oral antihistamines and antipyretics for up to 24 hours following the infusion and an oral corticosteroid (e.g., 4 mg dexamethasone) to decrease nausea and vomiting. Maintain adequate oral fluid intake.
-Monitor fluid balance and serum electrolytes.
-Consider low-dose aspirin on Days 1 through 8 of each 28-day cycle.
-Monitor for thrombosis.

Use: For the treatment of adult patients with relapsed or refractory hairy cell leukemia (HCL) who received at least 2 prior systemic therapies, including treatment with a purine nucleoside analog (PNA)

Tell your doctor if you have ever had:

• kidney disease; or

• a condition that affects your blood and blood vessels (such as hemolytic uremic syndrome or severe thrombotic microangiopathy).

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

Do not use moxetumomab pasudotox if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using moxetumomab pasudotox and for at least 30 days after your last dose. Tell your doctor right away if you become pregnant.

You should not breastfeed while using moxetumomab pasudotox.

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

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

Some side effects may occur during the injection. Tell your caregiver if you feel dizzy, nauseated, hot or cold, light-headed, or have a headache, muscle pain, cough, trouble breathing, or fast heartbeats.

Moxetumomab pasudotox can damage red blood cells, which may cause irreversible kidney failure. Get emergency medical help if you have: unusual bruising or bleeding, fever, confusion, tiredness or irritability, stomach pain, vomiting, dark urine, fast heartbeats, and little or no urination.

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

• low red blood cells (anemia)--pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet;

• signs of an electrolyte imbalance--muscle spasms or contractions, numbness or tingly feeling, nausea, fast or irregular heartbeats, seizure; or

• capillary leak syndrome--dizziness, weakness, cough, trouble breathing, and sudden swelling or weight gain.

Serious side effects may be more likely in older adults.

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

Common side effects of moxetumomab pasudotox may include:

• swelling in your arms, legs, or face;

• nausea, diarrhea, constipation;

• headache, tiredness;

• fever; or

• anemia.

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 moxetumomab pasudotox, 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.