Immunotherapy helps harness your body’s own immune system to target and kill cancer. It's an umbrella term that describes several treatments. Some types of immunotherapy boost your disease-fighting powers overall. Others teach it to attack specific kinds of cells found in tumors.
Immune Checkpoint Inhibitors
When your immune system attacks invaders like bacteria and viruses, it uses a system of "brakes" called checkpoints to stop it from attacking your own healthy cells. Cancer cells sometimes turn these checkpoints on or off so they can hide.
Immune checkpoint inhibitors are drugs that release the brakes on your immune system. Seven of these drugs are approved to treat cancer. They block the proteins PD-1, PD-L1, and CTLA-4 on the surface of immune cells, to let these cells go after the cancerous growth.
- Pembrolizumab (Keytruda)
- Nivolumab (Opdivo)
- Cemiplimab (Libtayo)
- Atezolizumab (Tecentriq)
- Avelumab (Bavencio)
- Durvalumab (Imfinzi)
- Ipilimumab (Yervoy)
Adoptive Cell Therapies
This group of treatments removes some of your own immune cells and either boosts their numbers or changes them in a lab so they can find and kill more cancer cells.
Tumor-infiltrating lymphocyte (TIL) therapy. T cells are powerful white blood cells that fight infections. In this treatment, doctors remove T cells that have started to attack your tumor. They grow a large batch of these cells, called tumor-infiltrating lymphocytes (TILs), in a lab. They then put these activated fighters back into your body.
Engineered T-cell receptor (TCR) therapy. This treatment removes T cells from your blood and reprograms them in a lab so they can find the cancer more easily. The engineered T cells look for tiny targets on the surface of your cancer cells.
The FDA hasn't approved any TCR therapies. These treatments are being tested in people with certain types of sarcoma (a soft-tissue cancer) and late-stage melanoma skin cancer.
CAR T-cell therapy. Doctors add special receptors to the surface of your T cells so they can lock onto and destroy your exact kind of cancer. Only two CAR T-cell therapies are FDA-approved:
- Tisagenlecleucel (Kymriah) treats people up to age 25 with acute lymphoblastic leukemia and adults with certain types of large B-cell lymphoma.
- Axicabtagene ciloleucel (Yescarta) treats adults with some types of large B-cell lymphoma, such as non-Hodgkin’s lymphoma.
Researchers are looking at new ways to use CAR T-cell therapies against cancer. One approach is to take these cells from healthy donors and make ready-to-go treatments for people with cancer.
Natural killer (NK) cell therapy. These immune cells attack foreign invaders like cancer in your body. Adding CARs to NK cells helps them target the cancer even better.
Antibodies are proteins your immune system makes. They find and stick to other proteins called antigens on cancer cells. Then they recruit other parts of your immune system to destroy the cancer.
Researchers can make antibodies in the lab. They're called monoclonal antibodies, and they work in different ways:
Naked monoclonal antibodies are the most common type used in cancer treatment. They're called naked because they’re unattached to anything. These antibodies boost your immune system's response against the cancer, or block antigens that help the cancer grow and spread.
Conjugated monoclonal antibodies have a chemotherapy drug or radioactive particle attached to them. The antibodies attach directly to cancerous cells. This reduces side effects and helps chemotherapy and radiation treatments work better.
Bispecific monoclonal antibodies attach to two proteins at once. Some attach to both a cancer cell and an immune cell, which helps the immune system attack the cancer. The leukemia drug blinatumomab (Blincyto) attaches to a protein on leukemia cells, and to a protein on T cells.
The FDA has approved more than a dozen monoclonal antibodies to treat several types of cancer. Research is underway to see how this treatment might work against other cancer types.
Oncolytic Virus Therapy
Viruses like the flu infect cells and make us sick. Oncolytic viruses are a special type that infects and kills cancer cells without harming healthy cells. The FDA has approved one oncolytic virus, talimogene laherparepvec (T-VEC, Imlygic), to treat metastatic melanoma.
These use your immune system to prevent or treat cancer. Cancer vaccines are made from dead cancer cells, proteins or pieces or proteins from cancer cells, or immune system cells.
Four vaccines are approved to prevent cancer:
- Cervarix, Gardasil, and Gardasil-9 protect against the human papillomavirus (HPV), which is linked to cancers of the cervix, throat, vagina, vulva, anus, and penis.
- Hepatitis B (HBV) vaccine (HEPLISAV-B) protects against HBV infections that can cause liver cancer.
Three vaccines are FDA-approved to treat cancer:
- Sipuleucel-T (Provenge) treats advanced prostate cancer when hormone therapy doesn't work.
- Talimogene laherparepvec (T-VEC) treats melanoma skin cancer that has spread.
- Bacillus Calmette-Guérin, or BCG, treats early-stage bladder cancer.
Scientists are studying other cancer vaccines in clinical trials.
Immune System Modulators
Other types of immunotherapy boost the activity of your immune system in general. A more active immune system can better fight cancer. These drugs fall into a few classes:
Interleukins are a type of cytokine, a protein that some white blood cells make to control your immune system's response to cancer. A man-made version of the interleukin IL-2 increases the number of T cells and NK cells in your body. The IL-2 aldesleukin (Proleukin) is approved to treat advanced kidney cancer and metastatic melanoma.
Interferons are another type of cytokine that makes your immune cells more active against cancer. IFN-alfa treats cancers such as leukemia, sarcoma, lymphoma, and melanoma.
Immunomodulators (IMiDs) kick-start immune system reactions to treat some types of cancer. They include:
- Imiquimod (Aldara, Zyclara)
- Lenalidomide (Revlimid)
- Pomalidomide (Pomalyst)
- Thalidomide (Thalomid)
- Bacillus Calmette-Guérin, or BCG, which treats early-stage bladder cancer