Immunotherapy is used to stimulate the body's immune system Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more against cancer. These treatments target specific genetic characteristics of the tumor cells. The genetic characteristics of tumors do not depend on what organ in the body the cancer develops. So these drugs may be effective against many types of cancer. (See also Cancer Treatment Principles Cancer Treatment Principles Treating cancer is one of the most complex aspects of medical care. It involves a team that encompasses many types of doctors working together (for example, primary care doctors, gynecologists... read more .)
There are several different types of treatments that doctors use to stimulate the immune system. And this area of cancer treatment is being intensively studied. The National Cancer Institute maintains an up-to-date list of immunotherapy drugs (as well as other drugs used to treat cancer). The list provides a brief summary of each drug's uses and links to additional information.
Monoclonal antibody therapy involves the use of antibodies produced in a laboratory to target specific proteins on the surface of cancer cells. There are many such antibodies available, and others are currently being studied. Trastuzumab is one such antibody, which attacks the HER-2/neu receptor present on the surface of cancer cells in 25% of women with breast cancer. Trastuzumab enhances the effect of chemotherapy drugs.
Rituximab is highly effective in treating lymphomas and chronic lymphocytic leukemia. Rituximab linked to a radioactive isotope can be used to deliver radiation directly to lymphoma cells.
Gemtuzumab ozogamicin, a combined antibody and drug, is effective in some people with acute myeloid leukemia.
Several monoclonal antibodies modify the function of immune checkpoints Defenses Against Cancer After a cell becomes cancerous, the immune system is often able to recognize it as abnormal and destroy it before it replicates or spreads. The cancerous cells may be completely eliminated,... read more , which help to control the immune system, and in so doing stimulate the body's natural anticancer immunity. Drugs called checkpoint inhibitors may block checkpoints, which are proteins that help turn the immune response off and on. Some cancers activate these checkpoints and turn off the immune system's ability to attack the cancer. Checkpoint inhibitors such as CTLA-4 (ipilimumab and tremelimumab) and PD1 (cemiplimab, dostarlimab, nivolumab, and pembrolizumab) or PD-L1 (durvalumab, atezolizumab, and avelumab) allow the immune system to attack the cancer. For example, pembrolizumab can be used for any advanced cancer with a DNA-repair defect independent of where the cancer is in the body. Checkpoint inhibitors are sometimes given alone or combined with other anticancer drugs.
Modified T cells
T cells T cells One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more are cells of the immune system that can recognize and destroy foreign cells. In this form of cancer treatment, T cells are removed from the blood of a person with cancer. Then in the laboratory, doctors modify these T cells genetically so that they recognize and attack that person's cancer cells. Then they return the modified T cells to the person. The most common example of this strategy is termed chimeric antigen receptor (CAR)-T-cells. CAR-T-cells are an effective therapy in people with acute lymphoblastic leukemia Acute Lymphoblastic Leukemia (ALL) Acute lymphoblastic leukemia is a life-threatening disease in which the cells that normally develop into lymphocytes (a type of white blood cell) become cancerous and rapidly replace normal... read more , B-cell lymphomas, and multiple myeloma Multiple Myeloma Multiple myeloma is a cancer of plasma cells in which abnormal plasma cells multiply uncontrollably in the bone marrow and occasionally in other parts of the body. People often have bone pain... read more .
Related techniques involve growing the extracted T cells in a culture and activating them by exposure to a certain signaling substance used by the body's cells. Alternatively, T cells may be extracted from the person's tumor, cultured to create a larger amount, and then reinfused.
Biologic response modifiers stimulate normal cells to produce chemical messengers (mediators) that improve the immune system's ability to find and destroy cancer cells. The effects are generalized and not specific to only certain cancers.
Interferon (of which there are several types) is the best-known and most widely used biologic response modifier. Almost all human cells produce interferon naturally, but interferon can also be made through biotechnology. Although its precise mechanisms of action are not totally clear, interferon has a role in the treatment of several cancers, such as Kaposi sarcoma and malignant melanoma.
Interleukins are messengers produced by certain immune system cells (activated T cells T cells One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more ). Giving interleukins can help in the treatment of metastatic melanoma and may be of benefit in kidney cancer. Interleukin 2, which is produced by certain white blood cells, can be helpful in renal cell carcinoma and metastatic melanoma.
Vaccines composed of material derived from cancer cells can boost the body's production of antibodies or immune cells that can attack the cancer. Extracts of weakened tuberculosis bacteria, which are known to boost the immune response, have been successful when instilled into the bladder to prevent recurrence of bladder tumors.