How Do Bispecific T-cell Engager Antibodies Work?

Bispecific T-cell engager (BiTE) antibodies are a class of drugs used to treat Philadelphia chromosome-negative relapsed or refractory B-cell precursor acute lymphoblastic leukemia (a type of cancer of the white blood cells).

BiTE antibodies are artificial bispecific monoclonal antibodies that work by exerting action selectively and directing the human immune system to act against tumor cells. They activate endogenous T-cells by connecting CD3 in the T-cell receptor complex with CD19 on benign and malignant B cells. This mediates the formation of a synapse between the T cell and the tumor cell, upregulation of cell adhesion molecules, production of cytolytic proteins, release of inflammatory cytokines, and proliferation of T cells, which results in redirected lysis of CD19+ cells.

BiTE antibodies are administered via slow injection (infusion) into a vein through a special machine (infusion pump), typically over four weeks (28 days), followed by two to eight weeks when the medication is not given. This treatment period is called a cycle, and the cycle may be repeated as necessary.

BiTE antibodies work in the following ways:

• They work by slowing or stopping the growth of cancer cells in the body.
• They direct a host's immune system, more specifically the T cells’ cytotoxic activity against cancer cells.

BiTE antibodies are used to treat relapsed or refractory B-cell precursor acute lymphoblastic leukemia.

Some of the common side effects include:

• Nausea
• Vomiting
• Heartburn
• Diarrhea
• Back/muscle or joint pain
• Abdominal pain
• Headache
• Constipation
• Tiredness/weakness
• Loss of appetite
• Pain at the injection site

Other rare side effects include:

• Dizziness 
• Fatigue 
• Insomnia 
• Chills, sore throat, fever, or cough
• Rash/hives/itching
• Hypotension (low blood pressure)
• Thrombocytopenia (low blood platelet count)
• Anemia (low red blood cell count)
• Weight gain
• Shortness of breath
• Tremor (an involuntary, rhythmic muscle contraction leading to shaking movements in one or more parts of the body)
• Peripheral edema (swelling of lower legs or hands)
• Hypokalemia (low blood potassium level)
• Hyperglycemia (high blood glucose level)
• Cytokine release syndrome (an acute systemic inflammatory syndrome characterized by fever and multiple organ dysfunction)

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 BiTE antibodies include:

• Blinatumomab
• Blincyto