Monoclonal antibodies are medicines that act like natural antibodies. Antibodies are proteins your immune system makes to help defend against a threat, like bacteria and viruses. Monoclonal antibodies can boost your immune system and stop or slow the progress of a disease. They have been designed to treat many conditions. Examples include some kinds of cancer and some autoimmune diseases like rheumatoid arthritis.

Monoclonal antibody treatment is given through a needle in a vein (I.V.) or by an injection. This treatment may be used alone. Or it may be given with other treatments, such as radiation therapy.