Elrexfio (elranatamab-bcmm) is a brand-name drug that’s prescribed for specific cases of multiple myeloma in adults. Elrexfio comes as a solution for injection that’s given by a healthcare professional.

Elrexfio was granted accelerated approval by the Food and Drug Administration (FDA). Accelerated approval is granted for drugs showing meaningful benefit in treating serious conditions with limited treatment options. Accelerated approvals rely on data available from early clinical trials. Full approval depends on additional trials to confirm benefit.

Elrexfio is approved by the Food and Drug Administration (FDA) to treat multiple myeloma that:

Elrexfio is a biologic and belongs to a drug class called bispecific B-cell maturation antigen (BCMA)-directed CD3 T-cell engagers. It’s not available in a biosimilar version.

Keep reading for specific information about the dosage of Elrexfio, including its strengths and how the medication is given. For a comprehensive look at Elrexfio, see this article.

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

Below is information about Elrexfio’s form, strengths, and dosages.

Elrexfio form

Elrexfio comes as a solution in a single-dose vial that’s given as a subcutaneous injection. Your doctor or another healthcare professional will give your injections.

Elrexfio strengths

Elrexfio comes in one strength of 40 milligrams per milliliter of liquid solution (40 mg/mL). Elrexfio vials are available in two sizes: 44 mg/1.1 mL and 76 mg/1.9 mL.

Typical dosages

Typically, your doctor will use the dosing schedule designed for Elrexfio. If side effects occur, they’ll change your dose schedule to address them, as needed. Your doctor can provide more information on how your treatment will be managed.

The following information describes dosages that are commonly prescribed or recommended. However, your doctor will determine the best dosage to fit your needs.

Dosage for multiple myeloma

Doctors may prescribe Elrexfio to treat certain multiple myeloma cases. If your doctor prescribes Elrexfio, you’ll start on Elrexfio’s step-up dosing schedule. Step-up dosing reduces the risk of side effects by slowly increasing your dose. The table below shows the typical step-up dosing schedule.

Day 1step-up dose 112 mg
Day 4step-up dose 232 mg
Day 8first treatment dose76 mg

Typically, you’ll take the first three doses following the above schedule. Based on your response, your doctor may move you to weekly dosing. Weekly dosing starts 1 week after the first treatment dose, according to the schedule below.

Weekly: 1 week after first treatment dose and through week 24regular treatment doses 76 mg

After 24 weeks, if your cancer responded well to Elrexfio, your doctor may continue it. Elrexfio treatment beyond week 25 follows the schedule below.

Every 2 weeks: week 25 and every 2 weeks after thatregular treatment doses76 mg

Your doctor may depart from the above schedules if you have certain side effects. For more information about your specific dosage and schedule, talk with your doctor.

Long-term treatment

Elrexfio is sometimes used as a long-term treatment. How long you receive it will be based on your cancer’s response. The length of treatment also depends on whether side effects occur that limit Elrexfio’s use. If you and your doctor determine that Elrexfio is safe and effective for you, you may receive it long term.

Before you start taking Elrexfio, your doctor will discuss the treatment plan with you. Talk with them if you have questions about how long you can expect to take Elrexfio.

Reducing Elrexfio’s dosage isn’t recommended. However, your doctor may delay dosing based on several factors, including:

  • how your body responds to Elrexfio
  • side effects you may have with Elrexfio
  • your liver function while taking Elrexfio

Other medical conditions you have can also affect your Elrexfio dosing schedule.

Dosage adjustments

Your doctor is unlikely to alter your dose unless you experience certain side effects. They may delay or stop Elrexfio for CRS, neurologic toxicity, ICANS, infection, abnormal blood tests, or liver problems. Other serious side effects or conditions may also prompt a change in the dosing schedule.

Inform your doctor of any new or changing symptoms. Mention fever, chills, difficulty breathing, dizziness, sore throat, fast heartbeat, painful urination, or weakness. Also, report thinking difficulties and changes in movement or numbness and tingling in the body. If you lack energy or appetite, your urine darkens, or skin yellows, tell your doctor right away. These may indicate serious side effects.

Be sure to tell your doctor about all medications you take and any health conditions or side effects you may have.

Elrexfio comes as a solution that’s given as a subcutaneous injection under the skin. You’ll likely go to an Elrexfio REMS-certified facility to receive it. Your doctor or another healthcare professional will give the doses. They’ll draw Elrexfio into a syringe and inject it in an area without tattoos, scars, or injury. Typically, it’s injected into the skin of your abdomen.

Your doctor may hospitalize you for certain doses. Typically, a hospital stay is recommended for 48 hours after your first step-up dose and for 24 hours after your second step-up dose. They’ll also give medications, such as Tylenol, Benadryl, or dexamethasone (a steroid), before the first three doses and possibly other doses. These actions help manage side effects.

If your dosing schedule is interrupted, you may need to return to the step-up dosing schedule. Your doctor may pause, delay, or stop Elrexfio entirely if you have certain side effects. Be sure to report any new symptoms to your doctor.

If you have questions about how to use Elrexfio, talk with your doctor or pharmacist. There’s also a helpful guide, brochure, and safety information on the manufacturer’s website.

If you miss your appointment for an injection, call your healthcare professional as soon as possible to reschedule. It’s important to try to attend all appointments. Your doctor needs to be able to monitor you for side effects.

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 Elrexfio.

Is the dosage of Elrexfio similar to the dosage of Blenrep?

No. While they’re both injected, the forms and how often you take each drug are different. Elrexfio is a solution for subcutaneous injection under the skin. Its treatment doses are typically weekly in the beginning, then every 2 weeks. Blenrep (belantamab mafodotin-blmf) is a powder that’s made into a solution and then diluted. It’s given via intravenous (IV) infusion every 3 weeks.

The dose in milligrams for each drug also differs because they have different active ingredients. Your doctor will prescribe the drug and the dosage that’s right for you.

To learn more about how these drugs compare, talk with your doctor.

How long does it take for Elrexfio to start working?

Elrexfio starts to work after your first dose, but not everyone responds the same. Your cancer may respond fully or only partially. In some people, the cancer doesn’t respond, and Elrexfio may be stopped. Elrexfio is typically administered unless the cancer worsens, or it causes certain harmful effects.

Because of how Elrexfio works, you likely won’t feel the drug working in your body. But your doctor will monitor you during treatment to check whether Elrexfio is working to treat your cancer. They can tell you whether Elrexfio is working and when it starts working for you.

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

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Elrexfio for you, they will prescribe the dosage that’s right for you.

If you have questions about the dosage of Elrexfio that’s best for you, talk with your doctor.

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

  • More about Elrexfio: For information about other aspects of Elrexfio, refer to this article.
  • Side effects: To learn about the side effects of Elrexfio, see the Elrexfio prescribing information.
  • Details about your condition: For details about your condition, see our cancer hub.

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.