In the U.S.—

• Monoclonal antibody
• antineoplastic

Gemtuzumab ozogamicin ( gem-TOO-ze-mab oh-zoh-GAM-ih-sin) is a monoclonal antibody. It is used to treat a certain type of leukemia which has recurred in patients who are 60 years of age or older. Gemtuzumab ozogamicin is an alternative to chemotherapy for these patients.

This medicine is to be administered only by or under the immediate supervision of your doctor. It is available in the following dosage form:

Parenteral
• Injection (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For gemtuzumab ozogamicin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to gemtuzumab ozogamicin, anti-CD33 antibody, or calicheamicin derivatives. Also tell your doctor and pharmacist if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Gemtuzumab ozogamicin may cause harm to the fetus when administered during pregnancy. There are no adequate, well-controlled studies in pregnant women. You should avoid becoming pregnant while receiving gemtuzumab ozogamicin. However, this medicine may be needed in serious diseases or other situations that threaten the mother's life. Be sure you have discussed this with your doctor.

Breast-feeding—It is not known if gemtuzumab ozogamicin passes into the breast milk. However, due to potential serious side effects in nursing babies from gemtuzumab ozogamicin, a decision should be made whether to stop nursing or to stop the drug.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of gemtuzumab ozogamicin in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of gemtuzumab ozogamicin in the elderly with use in other age groups. However, laboratory values associated with liver problems were observed more often in patients 60 years old or older.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking gemtuzumab ozogamicin, it is especially important that your doctor or pharmacist know if you are taking any of the following:

• Alpha interferons (e.g., Intron A, Roferon-A) or
• Amphotericin B by injection (e.g., Fungizone) or
• Antineoplastics, other (cancer medicine) or
• Antithyroid agents (medicine for overactive thyroid) or
• Azathioprine (e.g., Imuran) or
• Chloramphenicol (e.g., Chloromycetin) or
• Colchicine or
• Cyclophosphamide (e.g., Cytoxan) or
• Flucytosine (e.g., Ancoban) or
• Ganciclovir (e.g., Cytovene) or
• Mercaptopurine (e.g., Purinethol)
• Methotrexate (e.g., Rheumatrex)
• Plicamycin (e.g., Mithracin)
• Zidovudine (e.g., AZT, Retrovir)—Concurrent use of these agents with gemtuzumab ozogamicin increases the risk of infection

• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)—Risk of severe disease affecting other parts of the body

• High blood cell counts (peripheral blasts)—Risk of side effects increased by gemtuzumab ozogamicin

• Infection—Risk increased by gemtuzumab ozogamicin
• Liver disease—May be worsened by gemtuzumab ozogamicin
• Stem-cell transplant—Risk of side effects increased by gemtuzumab ozogamicin

Dosing—

The dose of gemtuzumab ozogamicin will be different for different patients. The dose that is used may depend on a number of things, including your size. Gemtuzumab ozogamicin is usually given by a doctor or nurse in the hospital or outpatient clinic. If you have any questions about the proper dose of gemtuzumab ozogamicin, ask your doctor.

It is very important that your doctor check you at regular visits to make sure this medication is working properly and to check for any unwanted effects.

While you are being treated with gemtuzumab ozogamicin, and after you stop treatment with it, do not have any immunizations (vaccinations) without your doctor's approval. Gemtuzumab ozogamicin may lower your body's resistance and there is a chance you might get the infection the immunization is meant to prevent. In addition, other persons living in your household should not take oral polio vaccine since there is a chance they could pass the polio virus on to you. Also, avoid persons who have taken oral polio vaccine within the last several months. Do not get close to them, and do not stay in the same room with them for very long. If you cannot take these precautions, you should consider wearing a protective face mask that covers the nose and mouth.

Gemtuzumab ozogamicin can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid people with infections.Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

• More common
  • Black, tarry stools;  bloating or swelling of face, arms, hands, lower legs, or feet;  blood in stools or urine;  bluish color of fingernails, lips, skin, palms, or nail beds;  blurred vision;  burning or stinging of skin;  chest pain ;  chills;  confusion;  convulsions (seizures);  cough or hoarseness ;  cracked lips;  decrease or increase in urine;  diarrhea;  difficulty in swallowing;  dizziness;  dry mouth;  excessive sweating;  fainting;  fast or slow heartbeat;  fatigue;  fever;  flushed, dry skin;  fruit-like breath odor;  headache, sudden and severe;  heavy, nonmenstrual vaginal bleeding;  inability to speak ;  increased thirst or hunger;  irregular heartbeat;  large, flat , blue or purplish patches in the skin;  light-headedness;  lower back, joint, or side pain;  loss of appetite;  mood changes;  muscle pain or cramps;  muscle trembling or twitching ;  nausea or vomiting;  numbness or tingling in hands, feet, or lips;  pain, difficulty, or burning while urinating;  painful cold sores or blisters on lips, nose, eyes, or genitals;  pale skin ;  persistent bleeding or oozing from puncture sites, mouth, or nose;  palpitations;  pinpoint red spots on skin;  pounding in the ears ;  red or purplish patches or spots on skin;  rapid, shallow breathing;  rapid weight gain;  severe or continuing dull nervousness;  shortness of breath;  slurred speech ;  small red or purple spots on skin;  sneezing;  sore throat;  sores, ulcers, or white spots on lips, tongue, or inside mouth ;  stomachache;  sweating ;  swelling or inflammation of the mouth, face, fingers, feet, or lower legs;  swollen glands;  temporary blindness;  tightness in chest ;  tingling of hands or feet;  troubled breathing, exertional;  unexplained nosebleeds ;  unusual bleeding or bruising;  unusual tiredness or weakness;  unusual weight gain or loss;  weakness in arm and/or leg on one side of the body, sudden and severe;  wheezing;  yellow eyes or skin 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome.

• More common
  • Acid or sour stomach;  belching;  difficulty in moving;  dry, red, hot, or irritated skin;  full or bloated feeling or pressure in the stomach;  heartburn;  indigestion;  lack or loss of strength;  muscle pain or stiffness;  pain, swelling, or redness in joints;  runny, stuffy nose;  stomach discomfort upset;  swelling of abdominal or stomach area;  trouble in sleeping 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.