Immunotherapy is an umbrella term for a variety of emerging cancer treatments that manipulate the body’s immune response. Recently the Food and Drug Administration has approved immunotherapy treatments for a variety of conditions including bladder and lung cancer and Hodgkin lymphoma.
“Harnessing the power of our patients’ own immune systems to help fight their cancers represents a very exciting step forward for all of us,” said Dr. Douglas Flora, a medical oncologist with St. Elizabeth Cancer Care. “The advances are happening in leaps and bounds: it seems like every month we get another drug which shows promise, adding another arrow to the quiver.”
Immunotherapy drugs fall into four different groups, according to the American Cancer Society, and they all work in different ways:
- Monoclonal antibodies are man-made versions of immune system proteins. An antibody is a protein that sticks to a specific protein called an antigen. Antibodies circulate throughout the body until they find and attach to the antigen. Once attached, they can recruit other parts of the immune system to destroy the cells containing the antigen. Researchers can design antibodies that specifically target a certain antigen, such as one found on cancer cells.
- Immune checkpoint inhibitors target molecules within T cells that act as “brakes.” T cells are the heavy lifters of the immune system. By taking the brakes off, checkpoint inhibitors free T cells to go after cancer cells. A checkpoint inhibitor was part of former President Jimmy Carter’s treatment regime for metastatic melanoma.
- Vaccines are substances put into the body to start an immune response against certain diseases. Some vaccines can help prevent or treat cancer. The human papillomavirus (HPV) vaccine, which the Centers for Disease Control (CDC) recommends for adolescents, is an example of a vaccine that can help prevent cervical, penile, anal, throat and other types of cancers.
- Non-specific immunotherapies bolster the immune system in a general way.
“These new drugs are changing the face of cancer care,” says Flora. “Now that we have proof of principle, researchers around the world are working to develop even better targeted therapies following these strategies.”
