Arzerra (ofatumumab) is a brand-name drug prescribed for chronic lymphocytic leukemia (CLL) in some adults. Arzerra comes as an intravenous (IV) infusion given by a healthcare professional. The dosage can vary depending on CLL severity.

Arzerra is approved by the Food and Drug Administration (FDA) for use in adults with CLL that meets any of the following conditions:

  • has not been treated before and fludarabine-based medications can’t be used
  • has relapsed (returned) after prior treatment
  • has not responded to prior treatment with fludarabine and Lemtrada (alemtuzumab)
  • has responded to other treatments but may benefit from extended Arzerra treatment

In some cases, Arzerra is prescribed along with other medications to manage your CLL.

Arzerra is a biologic and belongs to a drug class called CD20-directed cytolytic monoclonal antibodies. Arzerra isn’t available in a biosimilar version.

Keep reading for specific information about the dosage of Arzerra, including its strength and how you’ll receive the medication. For a comprehensive look at Arzerra, see this article.

Note: This article describes typical dosages for Arzerra provided by the drug’s manufacturer. However, your doctor will prescribe the Arzerra dosage that’s right for you.

Read below for recommended dosages of Arzerra and other details about the drug.

Arzerra form

Arzerra comes as a solution for IV infusion. It’s always given by a healthcare professional. You’ll receive your infusions in a hospital or clinic.

Arzerra strength

Arzerra comes in one strength of 20 milligrams per milliliter of solution (mg/mL). It’s available in a 5-mL and 50-mL vial.

Typical dosages

The following information describes dosages that are commonly prescribed for chronic lymphocytic leukemia (CLL). However, your doctor will determine the best dosage to fit your needs. If you have questions about your specific dosage, talk with your doctor.

Dosage for CLL that hasn’t been treated before

Doctors may prescribe Arzerra as a first treatment for CLL if fludarabine-based medications aren’t suitable. In this case, your doctor will recommend Arzerra in combination with Leukeran (chlorambucil).

If your doctor prescribes Arzerra, you’ll receive infusions in treatment cycles, each lasting 28 days (about 1 month). For cycle 1, you’ll get a dose of 300 mg on treatment day 1 and 1,000 mg on day 8. Then you’ll get a dose of 1,000 mg only on day 1 of each cycle. This means you’ll receive an Arzerra infusion about once per month.

It’s recommended to receive at least 3 treatment cycles for CLL but no more than 12.

Dosage for relapsed CLL

Arzerra may be prescribed for CLL that has relapsed after previous treatment. In this case, your doctor will prescribe Arzerra in combination with fludarabine and cyclophosphamide.

If your doctor prescribes Arzerra, you’ll receive infusions in treatment cycles, each lasting 28 days (about 1 month). For cycle 1, you’ll get a dose of 300 mg on treatment day 1 and 1,000 mg on day 8. Then you’ll get a dose of 1,000 mg only on day 1 of cycles 2–6. This means you’ll receive an Arzerra infusion about once per month.

No more than six cycles (6 months) of Arzerra are recommended for relapsed CLL.

Dosage for refractory CLL

Arzerra may be prescribed to manage CLL that hasn’t responded or has stopped responding to fludarabine and Lemtrada (alemtuzumab) treatment.

If your doctor prescribes Arzerra, your starting dose will likely be 300 mg, given once. After 1 week, you’ll get a dose of 2,000 mg once per week for 7 weeks. After 4 weeks, you’ll get a dose of 2,000 mg once every 4 weeks for four additional doses. This means you’ll receive Arzerra for about 6 months for refractory CLL.

Dosage for extended treatment of CLL

Arzerra is also approved to manage CLL long term. It’s prescribed for this use in people who’ve experienced a partial or complete response with other CLL treatments. A complete response means there are no signs of CLL in your body. A partial response is when treatment has worked but there are still some detectable cancer cells.

If your doctor prescribes Arzerra, your starting dose will likely be 300 mg, given once. After 1 week, you’ll get a dose of 1,000 mg. After 7 weeks, you’ll get another dose of 1,000 mg. Then you’ll continue to get 1,000 mg of Arzerra once every 8 weeks. For extended CLL treatment, you may receive Arzerra for up to 2 years.

Long-term treatment

Arzerra may be used as a short-term or a long-term treatment. The length of treatment will depend on your CLL. For details, see the dosage sections just above.

Before you start treatment with Arzerra, your doctor will discuss your treatment plan.

The Arzerra dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of your CLL
  • whether you’re taking other medications for CLL
  • whether your CLL has been treated in the past
  • other medical conditions you have that can also affect your Arzerra dosage

If you’d like to know more about your specific dosage, talk with your doctor.

Your doctor or another healthcare professional will give you Arzerra by IV infusion. You’ll likely go to your doctor’s office, an infusion center, or a hospital for your infusion. The amount of time your infusion takes will depend on your dose. In most cases, Arzerra infusions take 4–7 hours.

Your doctor will give you certain medications about 30 minutes to 2 hours before your infusion. Commonly called “premedications,” these drugs help lower side effects you may experience from your Arzerra infusion. The premedications you’ll likely receive include:

If you have any questions about how you’ll receive your Arzerra doses, talk with your doctor.

If you miss your appointment for an Arzerra infusion, call your doctor’s office as soon as possible to reschedule. They’ll adjust your dosing schedule as needed.

If you need help remembering your appointments, try setting an alarm or downloading a reminder app on your phone.

Below are some frequently asked questions about Arzerra and dosage.

Is the dosage of Arzerra similar to the dosage of Rituxan?

Yes, there are some similarities in the dosages of these drugs. However, there are differences as well, such as the timing of each dose and the strength. Both Arzerra and Rituxan (rituximab) are given as an IV infusion. Rituxan is typically given once per month. The dosing schedule for Arzerra depends on your specific situation. For details, see the “Arzerra dosage” section above.

The dose in mg for each drug differs because they have different active ingredients. And unlike Arzerra, the dose of Rituxan depends on your height and weight.

These medications are prescribed to treat chronic lymphocytic leukemia (CLL) in certain situations. Rituxan also has other approved uses. Your doctor will prescribe the drug and dosage that’s right for you. To learn more about how these drugs compare, talk with your doctor.

How long does it take for Arzerra to start working?

Arzerra starts to work after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. However, your doctor will monitor you during treatment to check whether the drug is working to treat your CLL.

Talk with your doctor if you have questions about what to expect with Arzerra treatment.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Arzerra for you, they will prescribe the dosage that’s right for you. If you have questions about the dosage of Arzerra that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Arzerra. These additional articles might be helpful:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.