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Generic name: belantamab mafodotinbel-AN-ta-mab-MA-foe-DOE-tin ]
Drug class: Miscellaneous antineoplastics

Medically reviewed by Judith Stewart, BPharm. Last updated on May 11, 2022.

What is Blenrep?

Blenrep is an antibody targeting B-cell maturation antigens (BCMA).

Blenrep is used to treat multiple myeloma in adults. This medicine is given after at least 4 other treatments did not work or have stopped working.

Blenrep was approved by the US Food and Drug Administration (FDA) on an "accelerated" basis. In clinical studies, some people responded to this medicine, but further studies are needed.

Blenrep is available only under a special program. You must be registered in the program and understand the risks and benefits of this medicine.


An eye doctor will need to examine your eyes before each dose of this medicine. Blenrep can cause changes to the surface of your eye that can lead to dry eyes, blurred vision, worsening vision, severe vision loss, and an ulcer on the surface of your eye. Tell your healthcare provider if you have any vision changes or eye problems during your treatment.

Even if your vision seems fine, it is important that you get your eyes checked during treatment with Blenrep because some changes can happen without symptoms and may only be seen on an eye exam.

You should use preservative-free lubricant eye drops at least 4 times per day during treatment with Blenrep as instructed by your healthcare provider. You should use caution when driving or operating machinery as this medicine may affect your vision.

Avoid wearing contact lenses during treatment with Blenrep unless directed by your eye specialist.

Before taking this medicine

To make sure Blenrep is safe for you, tell your doctor if you have ever had::

  • problems with your eyes;

  • vision problems; or

  • bleeding problems.

You may need to have a negative pregnancy test before starting this treatment.

Belantamab mafodotin can harm an unborn baby if the mother or the father is using this medicine.

  • If you are a woman, do not use Blenrep if you are pregnant. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 4 months after your last dose.

  • If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 6 months after your last dose.

  • Tell your doctor right away if a pregnancy occurs while either the mother or the father is using Blenrep.

This medicine may affect fertility (ability to have children) in both men and women. However, it is important to use birth control to prevent pregnancy because belantamab mafodotin can harm an unborn baby.

Do not breastfeed while using this medicine, and for at least 3 months after your last dose.

How is Blenrep given?

Blenrep is given as an infusion into a vein, usually every 3 weeks. A healthcare provider will give you this injection.

This medicine must be given slowly, and the infusion can take at least 30 minutes to complete.

An eye doctor will need to examine your eyes before each dose of this medicine. Blenrep may cause changes to the surface of your eyes, which can lead to vision changes. More serious effects may include an ulcer on the surface of your eye, or vision loss.

Blenrep may cause eye problems without causing any vision changes at first. Do not miss any eye examinations while using this medicine.

Follow any instructions about using artificial tears or lubricating eye gel to treat or prevent dry eyes.

Blenrep can also increase your risk of bleeding. You will need frequent blood tests.

Your doctor will determine how long to treat you with Blenrep.

Dosing information

Usual Adult Dose for Multiple Myeloma:

2.5 mg/kg (of actual body weight) IV over 30 minutes once every 3 weeks until disease progression or unacceptable toxicity

Use: For treatment of adult patients with relapsed or refractory multiple myeloma who have received at least 4 prior therapies including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent

What happens if I miss a dose?

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

What happens if I overdose?

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

What should I avoid while receiving Blenrep?

Do not wear contact lenses without your doctor's advice while you are receiving Blenrep.

Blenrep side effects

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

Some side effects may occur during the injection (infusion reaction). Tell your caregiver if you feel dizzy, tired, nauseated, light-headed, itchy, feverish, chilled, sweaty, short of breath, or have racing heartbeats, trouble breathing, or swelling in your face.

Call your doctor at once if you have:

  • sudden vision loss;

  • easy bruising, unusual bleeding; or

  • signs of bleeding in the brain - weakness, dizziness, confusion, numbness or tingling on one side of the body, loss of movement in your face.

Tell your eye doctor if you have any eye problems, changes in your vision, dry eyes, or vision loss.

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

Common Blenrep side effects may include:

  • vision changes;

  • eye changes found during an eye exam;

  • infusion reaction;

  • abnormal lab tests;

  • fever, tiredness; or

  • nausea.

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 Blenrep?

Other drugs may interact with belantamab mafodotin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines 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 Blenrep only for the indication prescribed.

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