Immunotherapy is a type of cancer treatment that involves boosting the body’s natural defenses against diseases. Here’s our guide to how immunotherapy works.
What is Immunotherapy?
Immunotherapy – also known as Biologic Therapy – is a cancer treatment that involves strengthening the body’s natural defenses – like your immune system. By strengthening the body’s natural defenses, the idea is that your body can fight back against cancer on its own.
Immunotherapy involves using substances either made by the body or in a laboratory. By adding these substances to the body, some believe that you can restore immune system functionality and boost your body’s ability to fight back against the disease.
How Does Immunotherapy Work?
Immunotherapy is believed to work in a few different ways, including:
— Stops or slows the growth of cancer cells
— Helps the immune system work more efficiently and effectively at destroying cancer cells
— Stops cancer from spreading to other parts of the body
Today, there are three main types of immunotherapy procedures available, which we’ll learn about in the next section.
Types of Immunotherapy Procedures
There are three main types of immunotherapy procedures, including monoclonal antibodies, non-specific immunotherapies, and cancer vaccines.
Antigens are harmful substance like bacteria, viruses, and parasites. When antigens enter your body, your body produces antibodies to fight back. Antibodies are proteins that are specifically designed to target antigens and thereby fight infection.
Today, researchers create monoclonal antibodies in a lab and then deliver those antibodies to patients. When these antibodies are given to patients, the body treats them like antibodies produced naturally by the body. This effectively strengthens the body’s defenses against the disease.
Monoclonal antibodies are thought to work because they are designed to fight against a specific protein in the cancer cells. This protein is only found in the cancer cells. The monoclonal antibodies do not affect the cells that don’t have that protein.
Monoclonal antibodies attach themselves to cancer cells in order to accomplish the following goals:
— Allow the Body’s Natural Immune System to Destroy the Cancer Cell: Your body’s immune system may not recognize cancer cells as being harmful. By “marking” cancer cells, monoclonal antibodies makes it easier for your body’s natural immune system to fight back against cancer cells.
— Prevent the Spread and Growth of Cancer Cells: Chemicals in the body tell cells to grow by attaching to receptors on the surface of cells. These chemicals are called “growth factors”. Cancer spreads so fast because some cancer cells make extra copies of the growth factor receptor. Monoclonal antibodies can block growth factor receptors, which prevents the growth signal from getting through to the cell.
— Irradiate Cancer Cells Directly: There’s a specific type of monoclonal antibody treatment called radioimmunotherapy. This process involves using monoclonal antibodies to deliver radiation directly to cancer cells. This process requires attaching radioactive molecules directly to monoclonal antibodies in a laboratory. The ultimate goal of this process is to deliver low doses of radiation specifically to the tumor while leaving surrounding healthy cells alone. The two most popular radioactive molecules used in radioimmunotherapy include ibritumomab tiuxetan (Zevalin) and tositumomab (Bexxar).
— Carry Drugs to Cancer Cells: Radioimmunotherapy involves using antibodies to deliver radiation to cancer cells. Pathologists can use a similar method to deliver medication to cancer cells. By attaching certain cancer fighting drugs – like Brentuximab vedotin (Adcetris) or trastuzumab emtansine (TDM-1 or Kadcyla) – to the monoclonal antibodies, the physician can ensure that the drugs get to exactly where they need to go.
— Diagnose Cancer: Sometimes, monoclonal antibody treatment is used to diagnose certain cancers. The body is flooded with radioactive molecules attached to monoclonal antibodies (like in radioimmunotherapy). Then, pathologists use special cameras to identify where the radioactive molecules built up in the body.
The side effects of monoclonal antibody therapy are typically mild. The most common side effects are similar to an allergic reaction and include things like:
— Low Blood Pressure
— Flu Like Symptoms
— Weakness And Tiredness
— Loss Of Appetite
— Upset Stomach
Drugs Used in Monoclonal Antibody Therapy
The U.S. Food and Drug Administration (FDA) has specifically approved a number of monoclonal antibody drugs to treat cancer, including:
— Alemtuzumab (Campath)
— Bevacizumab (Avastin)
— Cetuximab (Erbitux)
— Ipilimumab (Yervoy)
— Nivolumab (Opdivo)
— Ofatumumab (Arzerra)
— Panitumumab (Vectibix)
— Pembrolizumab (Keytruda)
— Rituximab (Rituxan)
– -Trastuzumab (Herceptin)
Just like monoclonal antibody treatment, non-specific immunotherapy treatment involves strengthening the immune system in its fight against cancer cells.
Typically, non-specific immunotherapies are used in conjunction with radiation therapy or chemotherapy. In some cases, non-specific immunotherapies are used as the primary cancer treatment.
The two most popular non-specific immunotherapy treatments include:
— Interferons: Interferons help the immune system fight cancer. Interferons are laboratory-produced compounds that appear to slow the growth and spread of cancer cells.
— Interleukins: Interleukins assist the body in destroying cancer cells. They encourage the body’s natural production of cancer-fighting cells in the immune system. One popular type of interleukin called Interluekin-2 (also known as IL-2, aldesleukin, or Proleukin) is used for kidney cancer and skin cancer like melanoma.
Cancer vaccines work in a similar way to other vaccines: they expose the body to small levels of an antigen in an effort to trigger the immune’s system response to that antigen. By triggering the immune system, the idea is that the cells produced by the immune system will go on to fight the proteins and related materials causing cancer throughout the body.
There are two main categories of cancer vaccines:
— Prevention Vaccine: Prevention vaccines are giving to someone with no symptoms of cancer. Popular vaccines like Gardasil and Cervarix, for example, prevent an individual from developing the human papillomavirus (HPV). HPV is linked to an increased risk of cervical cancer – which makes Gardasil and Cervarix cancer-fighting vaccines.
— Treatment Vaccine: Treatment vaccines train the body’s immune system to recognize and destroy cancer cells. There’s currently only one treatment vaccine for cancer approved in the United States. That vaccine is called sipuleucel-T (Provenge) and it’s targeted towards metastatic prostate cancer. Nevertheless, a number of cancer treatment vaccines are currently available through clinical trials and may hit the market in the future.
Clinical Trials for Immunotherapy
Immunotherapy is a relatively new procedure and its effectiveness is still debated. Today, immunotherapy is going through a wide range of clinical trials – with new evidence being released every year.
The best way to stay up to date on these clinical trials is at Cancer.net’s clinical trials page, which is found here.
At that page, you can view the latest scientific evidence and clinical trial information for traditional cancer treatments like chemotherapy as well as newer procedures like immunotherapy and stem cell transplantation.