Gemtuzumab ozogamicin is a monoclonal antibody linked to a chemotherapy drug. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage.

Gemtuzumab ozogamicin is used to treat a certain type (CD33-positive) of newly-diagnosed acute myeloid leukemia in adults and children at least 1 month old.

Gemtuzumab ozogamicin is also used to treat CD33-positive acute myeloid leukemia after other treatments did not work or have stopped working in adults and children at least 2 years old.

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

Gemtuzumab ozogamicin can increase your risk of bleeding or liver damage, either of which may be life-threatening.

Call your doctor at once if you have upper stomach pain, yellowing of your skin or eyes, rapid weight gain, swelling in your midsection, sudden numbness or weakness, problems with speech or vision, severe headache, or unusual bleeding (bleeding gums, vaginal bleeding, blood in your urine or stools, coughing up blood).

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

Gemtuzumab ozogamicin is given in a treatment cycle, and you will receive it only on certain days of each cycle. Your doctor will determine how long to treat you with this medicine.

You will be given other medications to help prevent serious side effects or an infusion reaction. Start and keep taking these medications exactly as your doctor has prescribed.

Gemtuzumab ozogamicin must be given slowly, and the infusion can take at least 2 hours to complete.

You will be watched closely for at least 1 hour after receiving this medicine, to make sure you do not have an infusion reaction.

Gemtuzumab ozogamicin may cause serious or life-threatening liver problems, including veno-occlusive disease (blocked blood vessels in the liver that can lead to liver damage).

You will need frequent medical tests. Your cancer treatments may be delayed based on the results.

You should not be treated with gemtuzumab ozogamicin if you are allergic to it.

Tell your doctor if you have ever had:

• liver disease;

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

• a stem cell transplant; or

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

Gemtuzumab ozogamicin can harm an unborn baby or cause birth defects if the mother or the father is using gemtuzumab ozogamicin.

• If you are a woman, 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 3 months after your last dose.

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

This medicine may affect fertility (ability to have children) in both men and women. However, it is important to use birth control to prevent pregnancy because gemtuzumab ozogamicin may harm the baby if a pregnancy does occur.

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

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

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

Avoid activities that may increase your risk of bleeding or injury. Use extra care to prevent bleeding while shaving or brushing your teeth.

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 or shortly after the injection. Tell your caregiver right away if you feel cold, itchy, feverish, light-headed, or short of breath. These symptoms could also occur up to 1 hour after your gemtuzumab ozogamicin injection.

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

• sores or white patches in or around your mouth, trouble swallowing or talking, dry mouth, bad breath, altered sense of taste;

• signs of liver problems--right-sided upper stomach pain, jaundice (yellowing of the skin or eyes), rapid weight gain, swelling in your arms or legs, painful swelling in your midsection;

• low blood cell counts--fever, flu symptoms, swollen gums, skin sores, cough, trouble breathing, pale skin, unusual tiredness;

• unusual bleeding--bleeding gums, abnormal vaginal bleeding, blood in your urine or stools, coughing up blood or vomit that looks like coffee grounds; or

• signs of bleeding in the brain--sudden numbness or weakness (especially on one side of the body), sudden severe headache, problems with speech or vision.

Gemtuzumab ozogamicin can increase your risk of bleeding or liver damage, either of which may be life-threatening. Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of gemtuzumab ozogamicin may include:

• bleeding;

• fever, infection;

• mouth sores;

• nausea, vomiting, constipation;

• headache; 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.

Gemtuzumab ozogamicin can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Other drugs may affect gemtuzumab ozogamicin, 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.