Immunotherapy

Immunotherapy uses your own immune system to fight cancer. There are several types of immunotherapies, and each works to help the immune system in a different way. Some boost your body’s immune system; others train your immune system to attack specific cancer cells.  

The immune system 

The body’s immune system helps protect us against disease and infection. To do this, the immune system must distinguish between cells that naturally belong in the body (self) and foreign cells (non-self). Antigens are substances the immune system recognizes as toxic and stimulate an immune response. An antigen may be a substance from the environment (such as bacteria, viruses, or pollen), or it may be from inside the body (such as cancer cells).   

Once the immune system recognizes that a cell is foreign (does not belong) in the body, it begins a series of reactions to identify, target, and eliminate the foreign cell. 

When the immune system functions normally, lymphocytes (type of white blood cell) travel through the body looking for and getting rid of anything that does not belong, including bacteria, viruses, and even cancer cells. These immune cells search for foreign cells by using their receptors to scan for antigens on the surface of the cells. Once the immune system discovers an antigen, it produces antibodies to attack the foreign cells or it activates lymphocytes to destroy them. 

Cancer and the immune system 

Many cancers are likely prevented by the immune system’s ability to recognize and destroy abnormal cells before they become cancer.

However, even a healthy immune system cannot always prevent cancers from forming. Some cancer cells can develop and grow even in the presence of a healthy immune system.

Immunotherapy seeks to boost or change how the immune system works to find and destroy cancer cells that have escaped immune detection. Several types of immunotherapies are either approved for use by the FDA or are under study in clinical trials to determine their effectiveness in treating various types of cancer.

Types of immunotherapies  

Immunotherapies being used or studied to treat blood cancer include: 

Chimeric antigen receptor (CAR) T-cell therapy  

A patient’s cells are removed through apheresis and modified in a laboratory so they can be reprogrammed to target tumor cells through a gene modification technique. The cells are then returned to the patient following chemotherapy.  

Learn more about CAR T-cell therapy.  

Cytokine treatment

Cytokines are proteins made by white blood cells that play an important part in the body’s immune response and affect the growth of all blood cells. Interferon is an example of a cytokine used in blood cancer treatment. Interferons are a natural substance that supports the body’s immune system. A specific type of interferon, called “interferon-alfa (INF-alfa),” when made in a lab, can be used in cancer treatment to boost white blood cells and attack cancer cells. Interferon can also slow cancer cell growth and cause tumor angiogenesis. Interferon is given as an injection.   

Immunomodulatory drugs

These drugs, also called “biological response modifiers,” boost the immune system by causing cells to release interleukin-2 (IL-2), a protein that increases the growth and activity of white blood cells. The drugs also have an “angiogenesis” effect, which means they stop tumors from forming new blood vessels that tumors need to grow. The immunomodulatory drugs used for blood cancer treatment are oral medications.

Donor lymphocyte infusion

Some blood cancer patients, especially those with chronic myeloid leukemia (CML), who have a relapse after stem cell transplantation or for whom transplantation is not successful may benefit from an immune cell treatment called donor lymphocyte infusion. 

During this procedure, doctors transfer lymphocytes (a type of white cell) from the original stem cell donor's blood to the patient. The infusion's goal is to attack or suppress leukemia cells by inducing an intense immune reaction against the patient's cancer cells. This is called a graft-versus-tumor (GVT) effect. 

Donor lymphocyte infusion has been helpful in treating relapsed CML after allogeneic bone marrow transplantation. It may also be a helpful treatment for patients with relapsed myeloma after allogeneic stem cell transplantation. 

Monoclonal antibody treatment

A monoclonal antibody is an immune protein made in a laboratory. It is designed to react with or attach to antigens—foreign substances such as bacteria, viruses, fungi, and allergens—on the surface of cancer cells. The monoclonal antibody aims for the molecule and attaches itself to the cell, blocking or interfering with the cell's activity. Because the drug attacks a specific target or marker on the cell, monoclonal antibody therapy is also called targeted therapy. 

Monoclonal antibody therapies can cause side effects, but they are generally milder than those of chemotherapy. Because they are designed to target and attack specific substances, they tend to leave normal cells unharmed. Targeted treatment may also increase the frequency of and prolong remissions.

There are three different types of monoclonal antibodies:

• Naked antibodies do not have another chemical or radioactive material attached. The antibodies recognize and attach to specific cells. They can destroy the cancer cell when they attach to the cell's antigen.
• Conjugated antibodies have radioactive isotopes (radioimmunotherapy), or chemotherapy (chemoimmunotherapy) attached to them. They deliver the toxic substance directly to the cancer cells and destroy them.
• Bispecific monoclonal antibodies are composed of two different monoclonal antibodies and can attach to two different targets at the same time. For example, a Bispecific T-cell Engager (BiTE®) binds to an immune cell (T cell) and a cancer cell target. By binding onto both, the drug brings the cancer cell and immune cels together, which is thought to cause the T cell to be activated and attack the cancer cell.

Monoclonal antibody therapies are generally given to individuals in an outpatient setting, usually over several weeks. The drug is delivered through a needle placed into a vein (intravenous infusion, or IV) in your arm. Your doctor may prescribe drugs before each infusion to reduce certain side effects. They regularly test your blood between treatments and after treatment is completed to look for other side effects.

Side effects such as fever and chills, tiredness, headache, and nausea are among the most commonly reported reactions. Other less common, but more severe, side effects include shortness of breath, a drop in blood pressure, an irregular heartbeat, chest pain, and low blood cell counts.

Immune checkpoint inhibitors

Checkpoints are molecules found on T cells, a type of white blood cell. These checkpoint molecules act as “brakes.” T cells circulate throughout the body looking for signs of infection and diseases, including cancer. When a T cell comes near any cell, it probes (looks for) specific proteins on the cell’s surface. If the T cell determines that it is a normal, healthy cell, it moves on to check other cells. If the proteins indicate that the cell is foreign or cancerous, the T cell attacks it. But cancer cells can sometimes send misleading signals to these checkpoints, telling the T cells that they are not harmful. Checkpoint inhibitors work by “taking the brakes off” T cells so that the T cells can now attack the cancer cells. 

Immune checkpoint inhibitors are given intravenously. The treatment period typically lasts 30 to 60 minutes, but the number of sessions may vary depending on the type of cancer and the drug given. 

Reduced-intensity allogeneic stem cell transplantation

Reduced-intensity allogeneic transplantation (sometimes called “mini-transplant” or “nonmyeloablative transplant”) uses lower, less toxic doses of chemotherapy and radiation than the conditioning regimen that is given before standard allogeneic transplantations. This type of transplant may be an option for certain patients who are older, who have organ complications or who are otherwise not healthy or strong enough to undergo standard allogeneic transplantation.  

Read more about reduced-intensity allogeneic stem cell transplantation. 

Clinical trials

If you are interested in immunotherapy, discuss the treatment with your doctor to learn whether you are a candidate. If the treatment is unavailable, your doctor may refer you to a clinical trial studying immunotherapy.  

Learn more about clinical trials.  

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