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Generic Name: ofatumumab (OH fa TOO mue mab)
Brand Names: Arzerra

Medically reviewed by Last updated on Feb 8, 2019.

What is Arzerra?

Arzerra (ofatumumab) is a monoclonal antibody that affects the actions of the body's immune system. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage.

Arzerra is used to treat chronic lymphocytic leukemia (CLL). In some patients, ofatumumab is given with another medicine called chlorambucil.

Arzerra is sometimes given after other medications have been tried without success.

Important information

If you have certain risk factors for hepatitis B, Arzerra can cause this condition to come back or get worse, which could lead to liver failure or death. You will need frequent blood tests to check your liver function.

Arzerra may cause a serious viral infection of the brain that can lead to disability or death. Call your doctor right away if you have any change in your mental state, decreased vision, or problems with speech or walking.

To be sure Arzerra is not causing harmful effects, your blood cells, kidney function, and liver function may need to be tested for several months, even after you stop using it. Do not miss any follow-up visits to your doctor.

Before you receive Arzerra, tell your doctor if you have hepatitis or severe COPD.

Before taking this medicine

Arzerra increases the risk of a serious viral infection of the brain that can lead to disability or death. This risk is higher if you have a weak immune system or are receiving certain medicines.

To make sure Arzerra is safe for you, tell your doctor if you have:

  • an active infection;

  • hepatitis; or

  • a history of liver disease or hepatitis B.

If you have certain risk factors for hepatitis B, the virus could become active again while you are using Arzerra and for up to several months after you stop using it. This has resulted in liver failure or death in some people using this medicine. Your doctor will perform blood tests to make sure you do not have conditions that may cause you to develop hepatitis B.

Using Arzerra during pregnancy could affect the immune system of the unborn baby. Tell your doctor if you are pregnant or if you become pregnant while using this medicine.

It is not known whether ofatumumab passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

How is Arzerra given?

Arzerra is injected into a vein through an IV. A healthcare provider will give you this injection. Ofatumumab must be given slowly through an IV infusion, and one dose can take up to several hours to complete.

Arzerra is usually given in a treatment cycle over several weeks, beginning with one infusion per week. Then you will receive your infusions less often, depending on the type of CLL for which you are being treated.

Your dosing schedule may change with further doses. Your doctor will determine how long to treat you with Arzerra.

You will be given other IV or oral (by mouth) medications to prevent certain side effects of Arzerra. You may need to start using these medications up to 2 hours before the start of your ofatumumab infusion.

You may also need to take antiviral medications if you are found to have any risk factors for hepatitis B. Follow your doctor's dosing instructions very carefully. Arzerra can cause hepatitis B to come back or get worse. You will need frequent blood tests to check your liver function.

Arzerra can have long lasting effects on your body. You may also need medical tests for a short time after you stop using this medication.

If you have hepatitis B you may develop liver symptoms after you stop taking this medication, even months after stopping. Your doctor may want to check your liver function for several months after you stop using Arzerra.

Arzerra dosing information

Usual Adult Dose of Arzerra for Chronic Lymphocytic Leukemia:

Patients should be premedicated before each infusion.

Total of 12 doses:
Initial dose (Dose 1): 300 mg
Doses 2 through 8: 1 week after initial dose, begin 2,000 mg weekly for 7 doses
Doses 9 through 12: 4 weeks after dose 8, begin 2,000 mg every 4 weeks for 4 doses

Each dose diluted in 1000 mL of 0.9% sodium chloride and given by slow intravenous infusion

What happens if I miss a dose?

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

What happens if I overdose?

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

What should I avoid while receiving Arzerra?

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Do not receive a "live" vaccine while using Arzerra. The vaccine may not work as well during this time, and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

Arzerra side effects

Get emergency medical help if you have signs of an allergic reaction to Arzerra: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver right away if you feel dizzy, nauseated, light-headed, confused, itchy, tingly, or have chest pain, jaw or arm pain, back pain, stomach pain, wheezing, chest tightness, or trouble breathing. These reactions can occur during the injection or within 24 hours afterward.

Call your doctor right away if you have signs of a serious brain infection: change in your mental state, decreased vision, weakness on one side of your body, or problems with speech or walking. These symptoms may start gradually and get worse quickly.

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

Call your doctor at once if you have:

  • fever, chills, cough with yellow or green mucus;

  • stabbing chest pain, wheezing, feeling short of breath;

  • liver problems--nausea, upper stomach pain, itching, tiredness, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

  • low blood cell counts--fever, chills, flu-like symptoms, swollen gums, mouth sores, skin sores, rapid heart rate, pale skin, easy bruising, unusual bleeding, feeling light-headed; or

  • signs of tumor cell breakdown--lower back pain, blood in your urine, little or no urination; numbness or tingly feeling around your mouth; muscle weakness or tightness; fast or slow heart rate, weak pulse, feeling short of breath; confusion, fainting.

Common Arzerra side effects may include:

  • fever, cough, flu symptoms;

  • cold symptoms such as stuffy nose, sneezing, sore throat;

  • trouble breathing;

  • diarrhea, nausea;

  • mild rash; or

  • tired feeling.

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.

What other drugs will affect Arzerra?

Other drugs may interact with ofatumumab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Arzerra only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.