Elrexfio: Uses, Side Effects and Dosage

Serious warnings and precautions box

What Elrexfio is used for:

• Elrexfio is a cancer medicine that contains the active substance “elranatamab” and is used to treat adults with a type of cancer of the bone marrow called multiple myeloma.
• It is used for patients who have had at least three different treatments that have not worked or have stopped working.

“For the following indication(s) Elrexfio has been approved with conditions (NOC/c). This means it has passed Health Canada’s review and can be bought and sold in Canada, but the manufacturer has agreed to complete more studies to make sure the drug works the way it should. For more information, talk to your healthcare professional.”

• the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least 3 prior lines of therapy including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody, and who have demonstrated disease progression on the last therapy.
• A serious side effect called cytokine release syndrome (CRS), which can be severe or fatal, may occur. Symptoms usually include fever (38°C or higher) and chills. Other symptoms of CRS may include difficulty in breathing, dizziness or feeling light-headed, feeling the need to throw up, headache, fast heartbeat, low blood pressure, feeling tired, vomiting, muscle pain and joint pain.
• Serious or life-threatening neurologic problems may occur after taking Elrexfio. Symptoms may include headache, confusion, difficulty with memory, difficulty speaking or slow speech, difficulty understanding speech, difficulty in writing, being confused about time or surroundings, being less alert, or excessive sleepiness, and seizures (fits). Some of these may be signs of a serious immune reaction called ‘immune effector cell associated neurotoxicity syndrome’ (ICANS). These effects can occur days or weeks after you receive the injection, and may be subtle at first.
• Your healthcare provider will monitor for signs and symptoms of CRS and neurological problems during treatment with Elrexfio. You should call your healthcare provider right away if you develop any of the signs and symptoms of CRS or neurologic problems at any time during your treatment with Elrexfio.

What is a Notice of Compliance with Conditions (NOC/c)?

A Notice of Compliance with Conditions (NOC/c) is a type of approval to sell a drug in Canada.

Health Canada only gives an NOC/c to a drug that treats, prevents, or helps identify a serious or life-threatening illness. The drug must show promising proof that it works well, is of high quality, and is reasonably safe. Also, the drug must either respond to a serious medical need in Canada, or be much safer than existing treatments.

Drug makers must agree in writing to clearly state on the label that the drug was given an NOC/c, to complete more testing to make sure the drug works the way it should, to actively monitor the drug’s performance after it has been sold, and to report their findings to Health Canada.

How Elrexfio works:

Elrexfio is an antibody, a type of protein which has been designed to recognize and attach to specific targets in your body. Elrexfio targets B cell maturation antigen (BCMA), which is found on multiple myeloma cancer cells, and cluster of differentiation 3 (CD3), which is found on T cells of your immune system. This medicine works by attaching to these cells and bringing them together, so that your immune system can kill the multiple myeloma cancer cells.

The ingredients in Elrexfio are:

Medicinal ingredients: elranatamab

Non-medicinal ingredients: edetate disodium dihydrate, L-histidine, L-histidine hydrochloride monohydrate, polysorbate 80, sucrose, water for injection.

Elrexfio comes in the following dosage forms:

• Solution for injection, 44 mg/1.1 mL (40 mg/mL)
• Solution for injection, 76 mg/1.9 mL (40 mg/mL)

Do not use Elrexfio if:

• you are allergic to elranatamab or any of the other ingredients of this medicine. If you are not sure if you are allergic, talk to your doctor or nurse before you are given Elrexfio.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take Elrexfio. Talk about any health conditions or problems you may have, including if you:

• had any infection within the last 4 weeks. Before you are given Elrexfio, your doctor will check your blood counts for signs of infection. If you have any infection, it will be treated before you start Elrexfio.

• are pregnant or plan to become pregnant. Elrexfio may harm your unborn baby.

• are breastfeeding or plan to breastfeed. It is not known if Elrexfio passes into your breast milk. You must not breastfeed during treatment and for 5 months after stopping treatment with Elrexfio.
• could become pregnant. You must use effective contraception during treatment and for 5 months after stopping treatment with Elrexfio.
• had a recent vaccination or are going to have a vaccination. You should not receive live vaccines from four weeks before until four weeks after you are treated with Elrexfio.

Other warnings you should know about:

• Do not drive, use tools, operate heavy or potentially dangerous machinery, or do things that could pose a danger to yourself until at least 48 hours after each of your 2 step-up doses, or as instructed by your healthcare provider. Some people may feel tired, dizzy, or confused while receiving Elrexfio.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

How you will receive Elrexfio:

• Your healthcare provider will give you Elrexfio through an injection under your skin (“subcutaneous” injection). It is given in the stomach area (abdomen) or thigh.

Usual dose:

• The dose of Elrexfio solution for subcutaneous injection is 76 mg, but the first two doses will be lower. Elrexfio is given as follows:

  • You will receive a “Step-up dose 1” of 12 mg on Week 1: Day 1
  • You will then receive a “Step-up dose 2” of 32 mg on Week 1: Day 4
  • You will then receive a “Treatment dose” of 76 mg on Week 2: Day 1
  • You will then continue receiving a “Treatment dose” once a week from Week 3 to Week 24, as long as you are getting benefit from Elrexfio.
  • You will then continue receiving a “Treatment dose” once every other week from Week 25 to Week 48, as long as you are getting benefit from Elrexfio.
  • You will then continue receiving a ‘treatment dose’ once every four weeks from Week 49 onwards, as long as you are getting benefit from Elrexfio.

• You will be given other medicines 1 hour before each of your first three doses of Elrexfio, which help lower the chance of side effects, such as cytokine release syndrome. These may include:

  • Medicine to reduce the risk of fever (such as acetaminophen)
  • Medicine to reduce the risk of inflammation (corticosteroids)
  • Medicine to reduce the risk of an allergic reaction (antihistamines such as diphenhydramine)
• You may also be given these medicines for later doses of Elrexfio based on any symptoms you have.
• You may also be given additional medicines based on any symptoms you experience or your medical history.
• Your doctor will monitor you for side effects for 48 hours after each of your first two doses (step-up doses). You should stay close to a healthcare facility for 48 hours after the first two doses in case you have side effects. Your doctor may recommend that you stay in the hospital after the first two doses.
• Your doctor will regularly check your blood counts, as the number of blood cells and other blood components may decrease.

Overdose:

This medicine will be given by your doctor or nurse. In the unlikely event that you are given too much, your doctor will monitor you for side effects.

If you think you, or a person you are caring for, have taken too much Elrexfio, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms.

Missed Dose:

It is very important to go to all your appointments to make sure your treatment works.

If you miss any appointments, call your healthcare provider as soon as possible to reschedule your appointment. It is important for you to be monitored closely for side effects during treatment with Elrexfio.

What are possible side effects from using Elrexfio:

• have when taking Elrexfio. If you experience any side effects not listed here, tell your healthcare professional.

Very common (may affect more than 1 in 10 people):

• Low levels of red blood cells (anemia)
• Feeling tired or weak
• Edema (excess fluid in body tissue, causing swelling of the hands and feet)
• Diarrhea, feeling sick (nausea), constipation, vomiting
• Low levels of blood platelets (cells that help blood to clot, thrombocytopenia)
• Nose and throat infection (upper respiratory tract infection)
• Lung infection (pneumonia)
• Low levels of types of white blood cells (lymphopenia, leukopenia)
• Decreased appetite
• Pain in your joints
• Fever
• Skin reactions at or near the injection site, including redness of the skin, itching, swelling, pain, bruising, rash, or bleeding
• Low level of “potassium” in the blood (hypokalemia)
• Dry skin
• Skin rash
• Increased level of liver enzymes “transaminases” in the blood
• Cough
• Being short of breath (dyspnea)
• Bladder infection (urinary tract infection)

Common (may affect up to 1 in 10 people):

• Low level of “phosphate” in the blood (hypophosphatemia)
• Low number of a type of white blood cell with a fever (febrile neutropenia)

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting Side Effects

You can report any suspected side effects associated with the use of health products to Health Canada by:

• Visiting the Web page on Adverse Reaction Reporting (canada.ca/drug-device-reporting) for information on how to report online, by mail or by fax; or
• Calling toll-free at 1-866-234-2345.

NOTE: Contact your healthcare professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.

Storage:

Elrexfio will be stored at the hospital or clinic by your doctor.

Keep out of reach and sight of children.

Store in a refrigerator (2°C to 8°C). Do not freeze. Do not shake.

Store in the original carton in order to protect from light.

If you want more information about Elrexfio:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes this Patient Medication Information by visiting the Health Canada Drug Product Database website: (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html; the manufacturer’s website https://www.pfizer.ca, or by calling 1-800-463-6001.

Last Revised: 2025-12-15