Biologic Therapy for Cancer Treatment

What is biologic therapy?

Biologic therapy (also called immunotherapy, biologic response modifier therapy, BRM, or biotherapy) uses the body’s immune system to fight cancer. The immune system helps protect your body from foreign invaders, such as bacteria or viruses. 

The immune system does not always recognize cancer cells as foreign. Even when the immune system does recognize cancer cells and tries to destroy them, its response is not always powerful enough to destroy the cancer. In addition, cancer cells appear to produce substances that protect them from the immune system.

Biologic therapies are designed to boost the immune system and its ability to fight cancer. Researchers do not completely understand how these treatments work but they believe that they stop or slow the growth of cancer cells. This makes it easier for the immune system to kill the cancer cells and to stop them from spreading to other parts of the body.

At this time, research does not show that biologic therapy is necessarily better at treating cancer than other types of treatment. It seems to work best for treating small, early-stage cancers. But research in this area is continuing and may produce safer, more effective treatments in the future.

What are the different types of biologic therapies?

Many different types of biologic therapies used to treat cancer: 

Colony-stimulating factors (CSFs) are cytokines that make the bone marrow produce more immune system cells and blood cells. One type of CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF), makes it possible to use higher doses of chemotherapy drugs because it strengthens the immune system.

Cytokines are chemicals that the immune system makes to control the activity of other immune system cells. Cytokines are used to reduce the side effects of other cancer treatments, including chemotherapy, which is important but is not really immunotherapy. Cytokines made in the laboratory are also used to boost the immune system in patients who are being treated with cancer vaccines.

Nonspecific immunomodulating agents - Nonspecific immunomodulating agents are biologic 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) are cytokines that help the body resist virus infections and cancers. IFN-alpha is used to treat certain kinds of cancer, including kidney cancer and melanoma. Researchers are not sure how IFN-alpha works but they think it might be by slowing the growth of cancer cells or of blood vessels that cancer cells need to grow, making cancer cells easier for the immune system to identify and destroy, or boosting the ability of immune system cells that attack cancer.  
• Interleukins (IL) are cytokines that increase the growth and activity of immune system cells. Interleukin-2 (IL-2) is sometimes used in combination with chemotherapy or other cytokines to make these treatments more effective. 
• Monoclonal antibodies can locate and attach to certain receptors on the outside of cancer cells. This stops the cells from sending a signal to divide. Treatments that block receptors are called receptor antagonists.
• Vaccines are used to treat existing cancers (therapeutic vaccines) or prevent development of cancer (prophylactic vaccines). Therapeutic vaccines strengthen the body's natural defenses against cancer. This can prevent the further growth of an existing cancer, prevent a treated cancer from recurring, or kill cancer cells that are still left from previous treatments. Prophylactic vaccines prevent healthy people from infection with cancer-causing viruses.
• Are there side effects of biologic therapies? 

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

Side effects of biologic therapy, which often mimic flulike symptoms, vary according to the type of therapy given and may include:

• 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.