90 yttrium (90Y) ibritumomab tiuxetan

Trade Names: Zevalin, IDEC-Y288

Type of Drug: 90 Y ibritumomab tiuxetan is a monoclonal antibody (antibodies made in the laboratory and designed to target substances called antigens, which are recognized by the immune system) with an attached radioactive substance (yttrium). It belongs to the class of chemotherapy drugs called radioimmunotherapeutic agents. It is used to treat certain non-Hodgkin’s lymphomas.

How Drug Works: 90 Y ibritumomab tiuxetan is like a “smart bomb.” The monoclonal antibody ibritumomab tiuxetan is directed against a certain receptor (CD20) located on B lymphocyte cells. This receptor is found on some normal lymphocytes and also on lymphocytes that are cancerous, as in non-Hodgkin’s lymphoma. Once attached, the radiation in the antibody (90 yttrium) kills the cells by exposing them to radiation. This treatment seems to work better if another monoclonal medicine called rituximab is given first.

How Drug Is Given: The drug is given in 4 steps. First, rituximab is given by an infusion into a vein over 4 or more hours. It attaches to the CD 20 receptor on B cell lymphocytes and helps clear some of the cancerous ones out of the blood. Second, a small dose of the 90 yttrium is given over 10 minutes into a vein. Then special x-rays are done to show where the yttrium has moved to in your body. This helps the doctors make sure that when the treatment dose of 90 Y ibritumomab tiuxetan is given it will go to all the right places. Third, about 7 to 9 days after the first dose of rituximab, another dose of rituximab is given over 4 or more hours, depending upon how well the dose is tolerated. Fourth, the 90 Y ibritumomab tiuxetan is given by a 10-minute injection into a vein. The doses given depend on your size, and the dose of rituximab is lower than if given alone.

Read the following information. If you do not understand it or if any of it causes you special concern, check with your doctor.

Before taking this drug, tell your doctor: • If you are trying to become pregnant, are pregnant, or breastfeeding. This drug may cause birth defects if either the male or female is taking it at the time of conception or during pregnancy. Men and women who are taking this drug need to use some kind of birth control. However, do not use oral contraceptives (“the pill”) without checking with your doctor. • If you think you may want to have children in the future. Many chemotherapy drugs can cause sterility. • If you have any of the following medical problems: chickenpox or exposure to chickenpox, gout, heart disease, congestive heart failure, shingles, kidney stones, liver disease, or other forms of cancer. • If you are taking any other prescription or over-the-counter drugs, including vitamins and herbals.

Should I avoid any other medicines, foods, alcohol, and/or activities? Your prescription and nonprescription medicines may interact with other drugs, causing harm. Certain foods or alcohol can also interact with drug products. Never begin taking a new medicine—prescription or nonprescription—without asking your doctor or nurse if it will interact with alcohol, food, or other medicines. Some drug products can cause drowsiness and affect activities such as driving.

Precautions: Many people get mild symptoms after receiving the treatment, including headache, feeling “blah” and without energy, nausea, abdominal pain, and feeling tired. Talk with your doctor or nurse about what to do for these symptoms.

While you are being treated with 90 Y ibritumomab tiuxetan, and after you stop treatment, do not have any immunizations (vaccinations) without your doctor’s okay. Try to avoid contact with people who have recently taken the oral polio vaccine. Check with your doctor about this.

90 Y ibritumomab tiuxetan can lower your blood counts (white blood cells, red blood cells, platelets). Your doctor will check your blood counts before and after each treatment to see how it affects your blood counts. Your doctor or nurse will give you specific instructions if your blood counts are low.

90 Y ibritumomab tiuxetan can cause a decrease in your white blood cell count, reaching the lowest point about 6 to 7 weeks after treatment is given. This can increase your risk of getting an infection. Report fever of 100.5°F or higher, or signs of infection such as pain in passing your urine, coughing, or bringing up sputum.

90 Y ibritumomab tiuxetan can lower your platelet count. This can increase your risk of bleeding. DO NOT take any aspirin or aspirin-containing medicines. Report unusual bruising or bleeding, such as nosebleeds, bleeding gums when you brush your teeth, or black, tarry stools.

Rarely, you can have a severe allergic reaction to the monoclonal antibody. Your nurse or doctor will watch you very closely during the treatment.

Tell all the doctors, dentists, and pharmacists you visit that you are taking this drug.

• Most of the following side effects probably will not occur. • Your doctor or nurse will want to discuss specific care instructions with you. • They can help you understand these side effects and help you deal with them.

Side Effects:

More Common Side Effects Mild to moderate symptoms with nausea, feeling “blah,” and feeling tired Decreased white blood cell count with increased risk of infection Decreased platelet count with increased risk of bleeding Decreased red blood cell count with increased risk of tiredness

Rare Side Effects Severe allergic reaction with rash, hives, fever and chills, swelling of face or lips, and difficulty breathing.

Side Effects / Symptoms of the Drug You will be given the treatment as an outpatient. Your doctor or nurse will watch you closely for an allergic reaction.

Other side effects not listed above can also occur in some patients. Tell your doctor or nurse if you develop any problems.

FDA Approval: This drug is approved for cancer treatment.