Biological Therapy

What is biological therapy?

Biological therapy (also called immunotherapy, biological response modifier therapy, or biotherapy) uses the body’s immune system to fight cancer. The cells, antibodies, and organs of the immune system work to protect and defend the body against foreign invaders, such as bacteria or viruses. Physicians and researchers have found that the immune system might also be able to both determine the difference between healthy cells and cancer cells in the body, and to eliminate the cancer cells.
Biological therapies are designed to boost the immune system, either directly or indirectly, by assisting in the following:

• Making cancer cells more recognizable by the immune system, and therefore more susceptible to destruction by the immune system
• Boosting the killing power of immune system cells
• Changing the way cancer cells grow, so that they act more like healthy cells
• Stopping the process that changes a normal cell into a cancerous cell
• Enhancing the body’s ability to repair or replace normal cells damaged or destroyed by other forms of cancer treatment, such as chemotherapy or radiation
• Preventing cancer cells from spreading to other parts of the body

How does the immune system fight cancer?

The immune system includes different types of white blood cells – each with a different way to fight against foreign or diseased cells, including cancer:

• lymphocytes – white blood cells, including B cells, T cells, and NK cells.
• B cells – produce antibodies that attack other cells.
• T cells – directly attack cancer cells themselves and signal other immune system cells to defend the body.
• Natural killer cells (NK cells) – produce chemicals that bind to and kill foreign invaders in the body.
• Monocytes – white blood cells that swallow and digest foreign particles.
• Dendritic cells – present the foreign cells to the immune system.

These types of white blood cells – B cells, T cells, natural killer cells, and monocytes – are in the blood and thus circulate to every part of the body, providing protection from cancer and other diseases. Cells secrete two types of substances: antibodies and cytokines. Antibodies respond to (harmful) substances that they recognize, called antigens. Specific (helpful) antibodies match specific (foreign) antigens by locking together. Cytokines are proteins produced by some immune system cells and can directly attack cancer cells. Cytokines are “messengers” that “communicate” with other cells.

What are the different types of biological therapies?

There are many different types of biological therapies used in cancer treatment.

Biological response modifiers (BRMs) change the way the body’s defenses interact with cancer cells. BRMs are produced in a laboratory and given to patients to:

• Boost the body’s ability to fight the disease.
• Direct the immune system’s disease fighting powers to disease cells.
• Strengthen a weakened immune system.

BRMs include nonspecific immunomodulating agents, interferons, interleukins, colony-stimulating factors, monoclonal antibodies, cytokine therapy, and vaccines:

nonspecific immunomodulating agents
Nonspecific immunomodulating agents are biological therapy drugs that stimulate the immune system, causing it to produce more cytokines and antibodies to help fight cancer and infections in the body. Fighting infection is important for a person with cancer.
interferons (IFN)
Interferons (IFN) are a type of biological response modifier that naturally occurs in the body. They are also produced in the laboratory and given to cancer patients in biological therapy. They have been shown to improve the way a cancer patient’s immune system acts against cancer cells. Interferons may work directly on cancer cells to slow their growth, or they may cause cancer cells to change into cells with more normal behavior. Some interferons may also stimulate natural killer cells (NK) cells, T cells, and macrophages – types of white blood cells in the bloodstream that help to fight cancer cells.
Interleukins (IL)
Interleukins (IL) stimulate the growth and activity of many immune cells. They are proteins (cytokines) that occur naturally in the body, but can also be made in the laboratory. Some interleukins stimulate the growth and activity of immune cells, such as lymphocytes, which work to destroy cancer cells.

Are there side effects of biological therapies?

As each person’s individual medical profile and diagnosis is different, so is his/her reaction to treatment. Side effects may be severe, mild, or absent. Be sure to discuss with your cancer care team any/all possible side effects of treatment before the treatment begins.

Side effects of biological therapy, which often mimic flu-like symptoms, vary according to the type of therapy given and may include the following:

-Fever
-Chills
-Nausea
-Vomiting
-Loss of appetite
-Fatigue

Specifically, cytokine therapy often causes fever, chills, aches, and fatigue. Other side effects include a rash or swelling at the injection site. Therapy can cause fatigue and bone pain and may affect blood pressure and the heart.