How Do Monoclonal Antibodies Work?

Reviewed on 7/27/2021


Monoclonal antibodies are a class of drugs used to treat inflammatory autoimmune disorders (conditions in which the immune system attacks the healthy parts of the body and causes pain, swelling, and damage), skin disorders, certain types of arthritis (such as rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis, and ankylosing spondylitis), and various cancers (chronic lymphocytic leukemia, Hodgkin’s lymphoma, and melanoma). The immune system is a complex network of cells, tissues, and organs. Together, they help the body to fight infections and diseases, and one of its primary functions is to detect and destroy the disease-causing agents, such as bacteria and viruses, and eliminate damaged or abnormal cells, such as cancer cells. The immune system recognizes an antigen (substances it sees as harmful or foreign) and produces antibodies (proteins that work to attack, weaken, and destroy antigens) that bind to the antigen and serves as a flag to attract disease-fighting molecules or as a trigger promoting cell destruction by other immune system processes.

Monoclonal antibodies are laboratory-produced molecules to serve as substitute antibodies that can restore, enhance, or mimic the immune system’s attack on cancer cells.

Monoclonal antibodies are prescription-only medicines and are available as a powder to be mixed with sterile water and administered intravenously (through a vein) in a prefilled syringe and as a solution (liquid) to inject subcutaneously (under the skin).

Monoclonal antibodies work in the following ways:

  • Flagging cancer cells: cancer cells that are coated in monoclonal antibodies may be more easily detected and targeted for destruction.
  • Triggering cell membrane destruction: monoclonal antibodies can trigger an immune system response that can destroy the outer wall (membrane) of a cancer cell.
  • Blocking cell growth: they block the connection between a cancer cell and proteins that promote cell growth—an activity that is necessary for tumor growth and survival.
  • Preventing blood vessel growth: a cancerous tissue needs blood supply to survive; they block the protein-cell interactions necessary for the development of new blood vessels.
  • Blocking immune system inhibitors: they bind to certain proteins which provide the cancer-fighting cells an opportunity to work with less inhibition.
  • Directly attacking cancer cells: they may attack the cell directly, leading to a series of events inside the cell that may cause it to self-destruct.
  • They block the inflammatory protein interleukin-6, which improves joint pain and swelling in arthritis and other symptoms caused by inflammation.
  • They slow down the body's defense system to prevent the body from rejecting the new organ after surgery (acute rejection).
  • In addition, they work by blocking the action of tumor necrosis factor, a protein in the body that causes inflammation and damage in arthritis and red scaly patches in psoriasis.


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Monoclonal antibodies are used in conditions such as:

Other potential uses for monoclonal antibodies being studied and are pending for Food and Drug Administration approval include:


Common side effects include:


Other rare side effects include:


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.


Ankylosing spondylitis is a type of __________ that affects the __________. See Answer


Generic and brand names of monoclonal antibodies include:


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