How Do Anti-BCMA Antibodies Work?

Anti-B-cell maturation antigen (BCMA) antibodies are a class of drugs used to treat relapsed or refractory multiple myeloma (a type of cancer of the bone marrow) for adult patients who have received at least four other medications including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent. The only drug that belongs to this class is “belantamab mafodotin,” a humanized IgG1κ monoclonal antibody that targets the BCMA conjugated with a cytotoxic agent, maleimidocaproyl monomethylauristatin-F (MMAF).

Multiple myeloma is cancer that begins in plasma cells (a type of white blood cell). These cells are part of the immune system, which helps protect the body from germs and other harmful substances. In time, myeloma cells collect in the bone marrow and solid parts of bones. Common symptoms may include:

• Bone pain, often in the back or ribs
• Fractures (broken bones)
• Weakness or fatigue
• Weight loss
• Frequent infections and fevers
• Feeling extremely thirsty
• Frequent urination

Anti-BCMA antibodies are available as a powder to be mixed with liquid and injected intravenously (into a vein) over 30 minutes once every three weeks.

Anti-BCMA antibodies work in the following ways:

• They belong to a class known as “antibody-drug conjugates” and work by killing the cancer cells.
• Belantamab mafodotin is an afucosylated monoclonal antibody that targets BCMA conjugated to the microtubule MMAF.
• BCMA is uniquely expressed on CD138-positive myeloma cells.
• Targeting BCMA allows belantamab mafodotin to be highly selective in its delivery of MMAF to multiple myeloma cells.
• Belantamab mafodotin binds to BCMA, is internalized into cells, and releases MMAF.
• MMAF binds to tubulin, stopping the cell cycle at the DNA damage checkpoint between the G2 and M phases, resulting in apoptosis (the death of cells which occurs as a normal and controlled part of an organism's growth or development).

Anti-BCMA antibodies are used to treat relapsed or refractory multiple myeloma in adults who have received at least four prior therapies including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.

Some of the common side effects include:

• Nausea
• Vomiting
• Blurred vision
• Loss of appetite
• Back/joint pain
• Weakness
• Tiredness
• Constipation
• Diarrhea
• Pyrexia (fever)

Other rare side effects include:

• Dizziness (feeling faint, weak, or unsteady)
• Unusual bleeding or bruising
• Thrombocytopenia (low blood platelet count)
• Keratopathy (any noninflammatory disease of the eye)
• Fatigue (an overall feeling of tiredness or lack of energy)
• Photophobia (increased sensitivity and aversion to light)
• Upper respiratory tract infection
• Serum creatinine increased

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of anti-BCMA antibodies include:

• Belantamab mafodotin
• Belantamab mafodotin-blmf
• Blenrep