Cytokines are considered non-specific immunotherapy medicines because they don’t respond to a particular target on most cancer cells. Instead, they boost the immune system in a more general way. This general boost can still lead to a better immune response to cancer. In many cases, cytokines are given after or at the same time as another cancer treatment, such as chemotherapy or radiation therapy.
Cytokines are proteins made by some immune system cells. They help control the growth and activity of other immune system cells and blood cells.
Right now, no cytokines are approved by the U.S. Food and Drug Administration to treat breast cancer.
There are two main cytokines being studied to treat cancer: interleukins and interferons.
Interleukins are a group of cytokines that help white blood cells, which are immune system cells, talk to each other and help the immune system produce cells that destroy cancer.
A specific interleukin, interleukin-2 (IL-2), helps immune system cells grow and divide more quickly, which means there are more of them to attack foreign cells in the body, such as cancer. A man-made version of IL-2 called Proleukin (chemical name: aldesleukin) has been approved by the FDA to treat metastatic kidney cancer and metastatic skin cancer.
Side effects of IL-2 can include chills, fever, fatigue, weight gain, nausea, vomiting, diarrhea, and low blood pressure. Rare but serious side effects include abnormal heartbeat, chest pain, and other heart problems.
Other interleukins, including IL-7, IL-12, and IL-21 are being studied as medicines to treat cancer.
Interferons are proteins that help the body fight off virus infections and cancers. Some research suggests that interferons may actually slow the growth of cancer cells. There are three types of interferons, which is abbreviated IFN: IFN-alpha, IFN-beta, and IFN-gamma.
Only IFN-alpha is FDA-approved to treat cancer. IFN-alpha boosts the ability of certain immune cells to attack cancer cells and may also slow the growth of the blood vessels that cancer tumors need to grow.
A man-made version of IFN-alpha, called Intron A, is used to treat hairy cell leukemia, non-Hodgkin lymphoma, and skin cancer, as well as hepatitis C and hepatitis B.
Side effects of interferons can include chills, fever, headache, fatigue, loss of appetite, nausea, vomiting, low while blood cell counts, skin rash, and thinning hair. These side effects can be severe and can make it hard for many people to tolerate interferon treatment.