Gemtuzumab ozogamicin injection may cause severe or life-threatening liver damage, including hepatic veno-occlusive disease (VOD; blocked blood vessels inside the liver). Tell your doctor if you have or have ever had liver disease or have had a hematopoietic stem-cell transplant (HSCT; procedure that replaces diseased bone marrow with healthy bone marrow). If you experience any of the following symptoms, call your doctor immediately: rapid weight gain, pain or swelling in the upper right part of the stomach, yellowing of the skin or eyes, nausea, vomiting, dark colored urine, or extreme tiredness.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests before, during, and after your treatment to check your body’s response to gemtuzumab ozogamicin injection.

Talk to your doctor about the risks of taking gemtuzumab ozogamicin injection.

Gemtuzumab ozogamicin injection is used alone or in combination with other chemotherapy medications to treat a certain type of acute myeloid leukemia (AML; a type of cancer that begins in the white blood cells) in adults and children 1 month of age and older who were recently found to have this cancer. It is also used alone to treat a certain type of AML in adults and children 2 years of age and older whose cancer worsened during or after treatment with other chemotherapy medications. Gemtuzumab ozogamicin injection is in a class of medications called monoclonal antibodies. It works by helping to kill cancer cells.

Gemtuzumab ozogamicin injection comes as a powder to be mixed with liquid and given through a needle or catheter placed into a vein. It is usually injected slowly over a period of 2 hours. Your doctor will tell you how often you will receive gemtuzumab ozogamicin injection. The dosing schedule depends on if you are being treated with other chemotherapy medications, if your cancer was previously treated, and how your body responds to the medication.

Gemtuzumab ozogamicin injection may cause serious or life-threatening reactions during an infusion and for up to a day afterwards. You will receive certain medications to help prevent a reaction before you receive each dose of gemtuzumab ozogamicin. A doctor or nurse will watch you closely while you are receiving the infusion and shortly after the infusion to be sure you are not having a serious reaction to the medication. Tell your doctor or nurse immediately if you experience any of the following symptoms that may occur during or within 24 hours after the infusion: rash, fever, chills, fast heartbeat, swollen tongue or throat, shortness of breath or difficulty breathing.

Your doctor may slow down your infusion, delay, or stop your treatment with gemtuzumab ozogamicin injection, or treat you with additional medications depending on your response to the medication and any side effects that you experience. Talk to your doctor about how you are feeling during and after your treatment.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before receiving gemtuzumab ozogamicin injection,

• tell your doctor and pharmacist if you are allergic to gemtuzumab ozogamicin, any other medications, or any of the ingredients in gemtuzumab ozogamicin injection. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amiodarone (Cordarone, Nexterone, Pacerone), anagrelide (Agrylin), chloroquine, chlorpromazine, cilostazol, citalopram (Celexa), disopyramide (Norpace), dofetilide (Tikosyn), donepezil (Aricept, in Namzaric), dronedarone (Multaq), escitalopram (Lexapro), flecainide (Tambocor), fluconazole (Diflucan), haloperidol (Haldol), ibutilide (Corvert), methadone (Methadose, Dolophine), ondansetron (Zuplenz, Sofran), pimozide (Orap), procainamide, quinidine (in Nuedexta), sotalol (Betapace, Sorine, Sotylize), and thioridazine. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with gemtuzumab ozogamicin injection, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• tell your doctor if you or anyone in your family has or has ever had long QT syndrome (condition that increases the risk of developing an irregular heartbeat that may cause fainting or sudden death), or if you have or have ever had or higher or lower than normal levels of sodium, potassium, calcium, or magnesium in your blood.
• tell your doctor if you are pregnant, plan to become pregnant, or plan to father a child. You should not become pregnant while you are receiving gemtuzumab ozogamicin injection. You will need to have a negative pregnancy test before you begin receiving this medication. Use effective birth control during your treatment with gemtuzumab ozogamicin injection and for 6 months after your final dose. If you are a male and your partner can become pregnant, you should use effective birth control during your treatment and for 3 months after your final dose. If you or your partner become pregnant while receiving gemtuzumab ozogamicin injection, call your doctor.
• tell your doctor if you are breastfeeding. You should not breastfeed while you are receiving gemtuzumab ozogamicin injection, and for 1 month after your final dose.
• you should know that this medication may decrease fertility in men and women. Talk to your doctor about the risks of receiving gemtuzumab ozogamicin.

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

Gemtuzumab ozogamicin injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• rash
• diarrhea
• constipation
• nausea
• vomiting
• headache
• pain
• pain, swelling, or sores in mouth or throat

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment:

• unusual or severe bleeding or bruising
• cough, shortness of breath, or difficulty breathing
• fast heartbeat
• fever, chills, sore throat, or other signs of infection

Gemtuzumab ozogamicin injection may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

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.

• Mylotarg^®