What is biological therapy?
Biological or biologic therapy is treatment designed to stimulate or restore the ability of the body's immune (natural internal defense) system to fight infection and disease. Biological therapy is also called biotherapy or immunotherapy and is commonly used to treat different kinds of cancers, as well as other conditions.
How does biological therapy work?
Biological therapy is a form of treatment that uses portions of the body's natural immune system to treat a disease. Biological therapy is also used to protect the body from some of the side effects of certain treatments.
Biological therapy often involves the use of substances called biological response modifiers (BRMs). The body normally produces these substances in small amounts in response to infection and disease. Using modern laboratory techniques, scientists can produce BRMs in large amounts for use in the treatment of cancer and other diseases, such as rheumatoid arthritis and Crohn's disease.
Depending on the agent, biological therapies can be given by mouth, intravenously, or as an injection.
What are examples of biological therapies?
Monoclonal antibodies, interferon, interleukin-2 (IL-2), and several types of colony-stimulating factors (CSF, GM- CSF, G-CSF) are forms of biological therapy. For example, interleukin-2 and interferon are two examples of BRMs being tested for the treatment of advanced malignant melanoma.
Monoclonal antibodies are a common type of biological therapy for many different cancers and other conditions. These are laboratory-produced antibodies that are designed to attack specific proteins expressed by abnormal cells. Examples of monoclonal antibody drugs include rituximab, which is used to treat non-Hodgkin's lymphoma, alemtuzumab (Campath) to treat chronic lymphocytic leukemia (CLL), and ipilimumab (Yervoy) for metastatic melanoma.
Other kinds of monoclonal antibodies used to treat cancers target proteins that are responsible for cell growth. Examples of these drugs include bevacizumab (Avastin), which targets vascular endothelial growth factor (VEGF), cetuximab (Erbitux) and panitumumab (Vectibix) to target the epidermal growth factor receptor (EGFR), and trastuzumab (Herceptin) and pertuzumab (Perjeta) to target the human epidermal growth factor receptor- 2 (HER-2).
Modes of biologic therapy that involve blocking the action of specific proteins of inflammation, called tumor necrosis factor (TNF), are being used for the treatment of a number of diseases, including rheumatoid arthritis and Crohn's disease. Etanercept (Enbrel) and infliximab (Remicade) are examples of commercially available injectable TNF-blocking treatments for patients with severe rheumatoid arthritis.
Biological therapy is a very active and exciting area of cancer research.
What are the side effects of biological therapy?
The side effects of biological therapy depend on the type of treatment. Side effects include flu-like symptoms such as chills, fever, muscle aches, weakness, loss of appetite, nausea, vomiting, and diarrhea. Some patients develop a rash, and some bleed or bruise easily. In addition, interleukin therapy can cause swelling.
Depending on how severe these problems are, hospitalization during treatment may be required for some patients. Side effects are usually short-term and gradually subside after treatment ends.
The long-term side effects of the various currently available biological therapies will be better defined with future research from which will also surely emerge new and valuable forms of these treatments.