BLENREP (belantamab mafodotin-blmf)

What Is Blenrep?

Blenrep® (belantamab mafodotin-blmf) is an antibody-drug conjugate (ADC), the first in a new class of treatments for myeloma. Blenrep is the combination of a monoclonal antibody (mAb) that binds to a specific receptor on the surface of myeloma cells called B-cell maturation antigen (BCMA). It is coupled with monomethyl auristatin F (MMAF), a drug that can kill myeloma cells. 

BCMA is involved in myeloma cell growth and survival and is found on the surface of cells in all patients with myeloma. When the monoclonal antibody portion of Blenrep attaches to BCMA, Blenrep enters the cell and releases MMAF, which leads to cell death. The antibody part of the ADC attracts your body’s own immune system to recognize myeloma cells and attack them. 

U.S. FDA Approves Blenrep for the Treatment of Relapsed/Refractory Multiple Myeloma

On Thursday, October 23, 2025, the U.S. Food and Drug Administration (FDA) announced its approval of Blenrep® (belantamab mafodotin-blmf)— "a B-cell maturation antigen (BCMA)-directed antibody and microtubule inhibitor conjugate — with bortezomib and dexamethasone for adults with relapsed or refractory multiple myeloma (RRMM) who have received at least two prior lines of therapy, including a proteasome inhibitor and an immunomodulatory agent."

The approval is supported by data from the phase III DREAMM-7 trial. Visit this article in the IMF Newsroom to learn more.

2025: International Approvals

United Kingdom: The UK Medicines and Healthcare products Regulatory Agency (MHRA) approved Blenrep for adults with multiple myeloma. This approval covers its use in combination with Velcade® (bortezomib) plus dexamethasone (BVd) for patients who have received at least one prior therapy, and in combination with pomalidomide plus dexamethasone (BPd) for patients who have received at least one prior therapy, including lenalidomide.

Japan: Japan's Ministry of Health, Labour and Welfare also approved Blenrep combinations for relapsed/refractory multiple myeloma (RRMM), according to this press release from GSK.

How Blenrep Works

Monoclonal antibodies are a type of immunotherapy. Manufactured in a lab rather than produced in the human body, the monoclonal antibody part of Blenrep is designed specifically to find and bind to the B-cell maturation antigen (BCMA) protein on the su face of myeloma cells.

Monoclonal antibodies can be used alone to treat myeloma. However, what is unique to Blenrep is that its monoclonal antibody is used to deliver a cytotoxic agent called monomethyl auristatin F (MMAF) directly to the myeloma cells, thereby killing the cancer cells.

Blenrep (belantamab mafodotin-blmf) mechanism of action

Who Can Be Treated with Blenrep?

As noted, in October 2025, Blenrep received approval from the FDA for the treatment of adult patients with relapsed or refractory multiple myeloma (RRMM) who have received at least 2 prior lines of therapy, including a proteasome inhibitor, and an immunomodulatory agent.

Blenrep is indicated in combination with the proteasome inhibitor Velcade® (bortezomib) and the steroid dexamethasone. This treatment regimen is known as BVd for short. For a more comprehensive discussion of the other two drugs that are part of this combination therapy, read these IMF publications:

• Understanding Dexamethasone in the Treatment of Myeloma
• Understanding VELCADE® (bortezomib)

Clinical Trial Experience with Blenrep

BVd vs. DVd

The DREAMM-7 study evaluated the efficacy of the BVd regimen in adult patients with RRMM who had received at least 1 prior line of therapy.

Interestingly, the DREAMM-7 study compared two different triplet (3-drug) combination therapies: Blenrep vs. the monoclonal antibody Darzalex® (daratumumab) with the combination of Velcade and dexamethasone (Vd) as the backbone. The study excluded patients who were refractory or intolerant of Velcade or Darzalex or had received prior BCMA-directed therapy. 

As published in the New England Journal of Medicine in August 2024, a total of 494 participants in the DREAMM-7 study were randomly assigned to receive either BVd (243 patients) or DVd (251 patients). At a median follow-up of 28.2 months (range, 0.1 to 40.0), median progression-free survival (PFS) was 36.6 months in the BVd group and 13.4 months in the DVd group. Overall survival (OS) at 18 months was 84% in the BVd group and 73% in the DVd group.

What Are the Dose and Schedule of Blenrep?

Blenrep is given through an intravenous (IV) infusion on an outpatientbasis at your doctor’s office or at a certified outpatient clinic. 

The length of time for the IV infusion varies from patient to patient and can be as short as 30 minutes. The recommended initial dosage of Blenrep is 2.5 mg/kg.

Blenrep is given every 3 weeks or on a schedule set by your doctor. The frequency of the dosing is often lengthened to reduce the risk of side effects, especially the risk of eye problems.

For the first 8 treatment Cycles, you will receive Blenrep in combination with Velcade and dexamethasone. After 8 Cycles, you will receive Blenrep alone, without Velcade and dex.

Special precautions with Blenrep

REMS

Blenrep is available only through a Risk Evaluation and Mitigation Strategy (REMS) restricted program because of the risk of eye problems. The FDA requires a REMS program if a specific drug or treatment has serious safety concerns. REMS programs support the use of such drugs or treatments and help ensure that the potential benefits outweigh the risks.

Before you can receive Blenrep, you must enroll in the Blenrep REMS program by completing the Patient Enrollment Form with your doctor. Ask your doctor about the risk of eye problems and the need for eye exams before and during treatment with Blenrep. Your doctor will give you the REMS Patient Guide that describes the risk of eye problems. For more information,
visit blenreprems.com.

What Are the Possible Side Effects of Blenrep?

Eye Problems and/or Ocular Toxicity

Blenrep can cause changes to the surface of your eyes (corneas). Promptly report to your doctor if you are taking Blenrep and experience any of the following symptoms:

• worsening vision
• blurred vision
• dry eyes
• sensitivity to light
• eye irritation
• eye pain
• eye infection

Cataract of the eye may also occur.

Prevention and treatment of eye problems

You will be required to have your eyes checked before you start treatment with Blenrep and before you receive each dose of Blenrep. Some eye problems can occur without you experiencing any symptoms, and some eye problems may be detectable only during an eye exam by an eye specialist (e.g., optometrist or ophthalmologist).

Your myeloma doctor may refer you to an eye specialist or you can find a qualified eye doctor in your area on the Blenrep website at blenrep.com/find-eye-doctor/.

It is helpful to use “preservative-free” artificial tears, starting with your first infusion of Blenrep and continuing through your last infusion of Blenrep. If you use contact lenses, ask the eye doctor if you need to switch to wearing glasses during treatment with Blenrep. Potential vision changes mean that you must exercise caution if you need to drive a vehicle or operate machinery during treatment with Blenrep.

Thrombocytopenia 

Thrombocytopenia is a low number of platelets in the blood. Platelets help blood to clot; fewer platelets can lead to easier bruising, bleeding, and slower healing. The “normal” level varies from laboratory to laboratory.

For example, at Mayo Clinic the “normal” level is at least 150,000 platelets per microliter of circulating blood. If the platelet count is less than 50,000, bleeding problems could occur. Major bleeding is usually associated with a reduction to less than 10,000. Blenrep may cause thrombocytopenia

Prevention and treatment of thrombocytopenia

Promptly report to your doctor any bleeding or bruising that you may experience. Decrease in platelets with Blenrep can be severe. Your doctor will monitor your platelet counts at baseline and during treatment.

Management of low platelet counts may include platelet transfusions or medication to stimulate the production of platelets

Embryo-fetal toxicity

Females of reproductive potential and males with female partners of reproductive potential must use effective contraception during treatment with Blenrep, and for 6 months after the last dose of treatment. Ask your doctor which birth control methods to use. Due to the potential for harm in the breastfed child, lactating women should not breastfeed during treatment with Blenrep and for 3 months after the last dose of treatment.

What Are Some Possible Common Side Effects of Blenrep or BVd?

Upper Respiratory Tract Infection

An upper respiratory tract infection may be a bacterial or a viral infection of the nose, throat, sinuses, or larynx. Possible respiratory infections include lung problems such as pneumonia (an infection in one or both lungs).

Prevention and treatment of upper respiratory tract infection

Promptly report your symptoms to your doctor. If your infection is serious and your white blood cell count is low, the doctor may pause your treatment until you recover or support you with medications to stimulate the production of new white blood cells.

Peripheral Neuropathy

Peripheral neuropathy (PN) is a serious condition that affects nerves in the hands, feet, lower legs, and/or arms. Myeloma patients may experience PN from the effects of the disease itself or from treatments for myeloma. Velcade is known to cause PN. The following is a list of symptoms of PN:

• numbness,
• tingling,
• burning, and/or
• pain.

Prevention and treatment of PN

Subcutaneous (SQ) Velcade causes significantly less peripheral neuropathy (PN) than intravenous (IV) administration. In a French trial, Grade 3–4 PN occurred in 6% of patients with SQ vs.16% with IV.

Diarrhea

Diarrhea is defined as 3 or more loose stools per day. Severe diarrhea is defined as 7 or more loose stools per day. Dizziness, lightheadedness, or fainting may occur due to dehydration caused by either excessive or persistent diarrhea

Prevention and treatment of diarrhea

• Take steps to prevent dehydration.
• Ask your doctor how to stay well hydrated.
• Report dizziness, lightheadedness, or fainting.
• Treatment may include antidiarrheal medication or IV fluids.
• Hospitalization may be needed in severe cases.

Fatigue

Fatigue that is commonly associated with cancer or with cancer treatments is different from and more severe than normal fatigue. It tends to last longer and includes the feeling of overall weakness (the medical term for this is asthenia).

Prevention and treatment of fatigue

• Report fatigue to your doctor.
• Medications may be prescribed to help manage symptoms.
• Stay moderately active, eat well, hydrate, and maintain a regular sleep schedule.
• Attend regular checkups to monitor red blood cell (RBC) counts.
• Discuss other medications or factors that may contribute to fatigue.

For more information, read the IMF's publication Understanding Fatigue.

Liver Problems 

Your liver enzymes may become elevated during treatment with Blenrep. Severe liver injury is rare. Blenrep can cause the reactivation of the hepatitis B virus (HBV), so be sure to report any history of this infection to your doctor and ask about prevention strategies.

Prevention and treatment of liver problems

• Liver function will be monitored with regular blood tests.
• Report symptoms immediately: 
  • jaundice (yellowing skin/eyes),
  • dark urine, 
  • abdominal pain, 
  • fatigue, or 
  • nausea.
• Management may include dose reduction or stopping the medication temporarily or permanently.

Patient Assistance for Blenrep

The “Together with BLENREP” program is designed to support patients during treatment with Blenrep. A dedicated Nurse Navigator can help you with healthcare insurance and coverage information for treatment with

Blenrep and for the eye exams required for Blenrep treatment, as well as with any insurance changes that may cause treatment interruption.

The Blenrep Copay Assistance Program may help with out-of-pocket medication costs for eligible patients with commercial insurance. The Blenrep Patient Assistance Program may offer this medicine at no cost to eligible patients. The GSK ViiV Healthcare Patient Access Programs Foundation, an independent non-profit organization separate from GSK, may help with information about third-party assistance for out-of-pocket costs.

Visit blenrep.com/support-resources/ for more information and to enroll in the “Together with BLENREP” program.