Your immune system keeps your body healthy by protecting against harmful germs and substances, and fighting the growth of abnormal cells, including cancer cells. But the immune system isn’t always able to find and destroy all cancer cells – because cancer cells have developed ways to hide from the immune system.

Immunotherapy is a cancer treatment that helps the immune system work better. Below, we discuss different types of immunotherapy, how they work and how they’re being used. You can use the links below to jump ahead to specific sections.

However, immunotherapy isn’t the best option for all types of cancers. If you or a loved one has been diagnosed with cancer, make sure to talk to an oncologist about immunotherapy and other cancer treatments. They’ll be able to explain the options and put together a personalized treatment plan.

What is immunotherapy for cancer? Treatments that help the body’s immune system fight cancer.

Immunotherapy gives the body’s immune system a boost to help it fight off cancer. The medicines can activate the immune system to strengthen the body’s natural defenses, and add to the immune system’s functionality, helping it work in new or boosted ways. By using immunotherapy to strengthen or enhance the immune system, the hope is that the body will be stronger and better at finding and destroying cancer cells.

Immunotherapy can be used alone or with other treatments, depending on the type of cancer and immunotherapy medicines.

Immunotherapy vs. chemotherapy

Chemotherapy is one of the most common cancer treatments and uses strong drugs to kill or slow the growth of fast-growing cells, including cancer cells. In comparison, immunotherapy uses medicines to make your immune system more effective at finding and destroying cancer. Both treatments are typically used as systemic treatments, meaning that the medications travel to cancer cells through your blood.

Chemotherapy and immunotherapy are often used as part of a combination treatment plan – sometimes together and sometimes with other cancer treatments. Chemotherapy is currently used to treat more types of cancers, in more ways, but that may change as we learn more about immunotherapy.

Types of immunotherapy medications for cancer and how they work

There are many different types of immunotherapy medicines used for cancer. Most are given as infusions or injections in an outpatient setting, so the person can go home the same day. But there are some treatments that require a hospital stay, and some oral immunotherapy medicines that can be taken at home. Your oncologist will provide specific information about immunotherapy medications, including how, where and how often they’re given.

Immune checkpoint inhibitors

One way the immune system deals with foreign substances is through “checkpoint” proteins on the immune cells. When the body finds a foreign substance, it turns on the protein, which triggers an immune response to destroy the cells containing the substance. But cancer cells have figured out a way to turn off these checkpoint proteins to avoid being attacked by the immune system.

Monoclonal antibodies are medicines that are made in a lab that can be used as checkpoint inhibitors. This means that they target the checkpoint proteins so that cancer cells can’t turn them off. This makes it easier for your immune system to find and destroy cancer cells.

Monoclonal antibodies are given through an infusion in your vein, usually during an outpatient procedure. The most common side effects of checkpoint inhibitors are diarrhea, fatigue, cough, nausea, skin rash, poor appetite, constipation, and muscle and joint pain. Serious side effects are less common.

Chimeric antigen receptor (CAR) T-cell therapy

T cells are a type of white blood cell that play an important role in our immune system. T cells have proteins called receptors that attach to the proteins (antigens) of foreign substances. These receptors and antigens are kind of like puzzle pieces, and it won’t work if you don’t have the exact match. Unfortunately, the body doesn’t always have the receptor that goes with the antigen of a specific cancer.

CAR T-cell therapy changes a patient’s blood so that it has the gene for the receptor (the chimeric antigen receptor) that can attach to the specific type of cancer that they have. CAR T-cell therapy is sometimes called adoptive cell therapy or cell-based gene therapy because it changes the genes inside the T cells.

This therapy involves collecting T cells by filtering them from a patient’s blood (a procedure called leukapheresis). The collected T cells are sent to a lab where the gene for the receptor is added, turning them into CAR T cells. The changed cells are given time to grow and multiply – usually several weeks. Once there are enough CAR T cells, the cells are put back into the body.

While CAR T-cell therapy can be valuable against hard-to-treat cancers, there can sometimes be serious or life-threatening side effects. People who get this type of immunotherapy will be carefully watched for several weeks afterward to make sure there aren’t any problems.

Cytokine therapy

The body has small proteins called cytokines that tell the immune system (and the cells that support it) what to do. Cytokines are always sending messages to the immune system, even when there isn’t a threat. This makes sure your immune system works correctly. One type of cytokine is called a chemokine. They are very helpful for your immune system because they can make immune cells go to a specific area of the body.

Cytokine immunotherapy uses lab-made medicines to increase the number of chemokines in your body. Having more chemokines increases the body’s ability to get immune cells where they need to go. This can make the body better at destroying cancer cells and managing the side effects of other cancer treatments.

Cytokine therapy medicines are injected under the skin or into a muscle or vein. Side effects are usually mild but include flu-like symptoms like chills, fever, headache, fatigue and nausea. There can be more serious side effects, so the treatment may be done at the hospital, especially if cytokines are given in higher doses.

Immunomodulators

These medicines stimulate specific parts of the immune system. There are three main types:

  • Immunomodulating drugs (IMiDs) – These medicines make your body produce more white blood cells and stop tumors from forming new blood vessels, which keeps them from growing beyond a certain size. Side effects can include drowsiness, fatigue, constipation, low blood cell count, nerve problems and blood clots.
  • Imiquimod skin cream – When applied to the skin, this drug causes a local immune response, which sends more cytokines to the area to help destroy skin cancer cells. This cream can cause skin reactions in some people.
  • Bacillus Calmette-Guérin (BCG) –BCG is a germ that doesn’t cause disease in humans. However, it can cause an immune response against cancer cells. It’s used to treat early-stage bladder cancer and some melanoma skin cancers. Flu-like symptoms are the most common side effects with BCG.

Oncolytic virus therapy

A virus works by entering a cell, using parts of the cell to make copies of itself, and then spreading the copies to the surrounding uninfected cells. Scientists have found that some viruses can be modified in a lab to target and attack cancer cells – these viruses are used for oncolytic virus therapy.

When an oncolytic virus infects a cancer cell, it can cause the cell to burst. This kills the cancer cell and releases cancer antigens, which causes an immune reaction that helps the body find and destroy nearby cancer cells (and possibly ones throughout the body). Side effects with this type of immunotherapy are generally mild and include flu-like symptoms.

Cancer vaccines

Vaccines teach the body how to protect itself against foreign substances. Some vaccines are used to prevent cancer, while others are used to treat it. Cancer vaccines include a small amount of an antigen that are associated with cancer. When a person gets a vaccine, it kicks off an immune response. Afterwards the body will recognize cells with that antigen as foreign and the immune system will know to destroy them. Side effects of cancer vaccines are usually mild and include flu-like symptoms.

Preventive cancer vaccines

Preventive cancer vaccines contain antigens for specific viruses that can lead to certain types of cancer. There are currently two vaccines to prevent cancer.

  • Human papillomavirus (HPV) vaccine – The HPV vaccine helps to prevent several cancers, including cervical cancer, head and neck cancers, anal cancer, penile cancer, vaginal cancer and vulvar cancer. This is a recommended vaccine for people between the ages of 9-26 years old and is sometimes an option for older people.
  • Hepatitis B vaccine – The Hepatitis B vaccine reduces your chance of getting liver cancer. Hepatitis B is a recommended immunization for babies.

Therapeutic cancer vaccines

Therapeutic cancer vaccines include tumor-related antigens that aren’t normally part of cells. Getting a therapeutic cancer vaccine helps your immune system recognize cancer cells as foreign substances that should be destroyed.

Therapeutic cancer vaccines may be used as part of cancer treatment to stop a tumor from growing or spreading. They’re also used to destroy cancer cells that remain after other cancer treatments and to help manage treatment side effects.

How long does it take immunotherapy to work?

It takes time for immunotherapy medications to work, and it may be two months before there’s any noticeable changes to the cancer. But the timing may be different depending on the stage and type of cancer, type of immunotherapy, and the body’s response to treatment.

Signs immunotherapy is working

During follow-up appointments, the oncologist will use physical exams, imaging tests and blood tests to check how cancer is responding to treatment. The best sign that immunotherapy is working is the size of the cancer during and after treatment. If it stays the same, gets smaller or becomes more controlled, the immunotherapy is working.

It’s possible that treatment side effects like inflammation may be a sign that immunotherapy is working, but side effects shouldn’t be used to tell if treatment is successful. Many people with a positive response to immunotherapy have no side effects at all.

Types of cancer that can be treated with immunotherapy

Immunotherapy treatments have been approved by the U.S. Food and Drug Administration (FDA) or are being tested for more than 20 types of cancer. But researchers are still learning about immunotherapy and when it’s most effective. So it may not be recommended for the type of cancer that you or your loved one has, or your oncologist may try other treatments first.

Cancers treated by immunotherapy include:

  • Bladder cancer – Available bladder cancer immunotherapy medications include targeted antibodies, cancer vaccines and checkpoint inhibitors.
  • Brain cancer – Targeted antibodies are currently used to treat brain cancer when other treatments don’t work.
  • Breast cancer – Breast cancer immunotherapy is sometimes used to treat breast cancer in people who make too much of a protein receptor called HER2. Approved treatments include targeted antibiotics and checkpoint inhibitors.
  • Cervical cancer – Checkpoint inhibitors and monoclonal antibodies are used to treat cervical cancer. And as mentioned above, the HPV vaccine is very effective at preventing the virus that causes cervical cancer.
  • Colorectal cancer – Targeted therapies and checkpoint inhibitors are used as colorectal cancer immunotherapy treatments. Immunotherapy may work better in people with hereditary colorectal cancer.
  • Esophageal cancer – Esophageal cancer immunotherapy treatments include targeted therapies and checkpoint inhibitors.
  • Head and neck cancer – The HPV vaccine helps prevent some of these cancers. Targeted antibodies and checkpoint inhibitors are used to treat head and neck cancers, and to help manage side effects of other treatments.
  • Kidney cancer – Cytokines, targeted therapies, monoclonal antibodies and checkpoint inhibitors are currently approved for kidney cancer.
  • Leukemia and lymphoma – Types of immunotherapy for leukemia include targeted antibodies, T-cell therapy and cytokines. For lymphoma, checkpoint inhibitors, cytokines and T-cell therapy are being used.
  • Liver cancer – Checkpoint inhibitors are being used to treat liver cancer. And as mentioned above, the hepatitis B vaccine can help prevent liver cancer. While there’s no vaccine for hepatitis C, the immunotherapy drugs that treat hepatitis C may stop liver cancer from developing.
  • Lung cancer – Immunotherapy is often a first treatment for lung cancer, sometimes with chemotherapy. Targeted therapies and checkpoint inhibitors are currently used for lung cancer immunotherapy.
  • Ovarian cancer – Monoclonal antibodies are currently used to treat ovarian cancer.
  • Pancreatic cancer – Oncologists sometimes use checkpoint inhibitors as immunotherapy for pancreatic cancer if a patient has cancer cells with specific genetic traits.
  • Prostate cancer – Prostate cancer immunotherapy treatments include a therapeutic cancer vaccine and checkpoint inhibitors. Immunotherapy is usually only used for advanced prostate cancer.
  • Sarcoma – Monoclonal antibodies are sometimes used to treat sarcoma, a rare type of cancer that starts in bones or soft issue.
  • Skin cancer – Immunotherapy treatments include checkpoint inhibitors, cytokines and oncolytic virus therapy for melanoma.
  • Stomach cancer – Checkpoint inhibitors, targeted antibodies are sometimes used for advanced stomach cancer.

Talk to an oncologist to decide if immunotherapy should be part of the treatment plan

Talking to an oncologist is the best way to learn which treatments would be best for you or your loved one. They’ll be able to explain the benefits and drawbacks of different therapies. They can also share information about clinical cancer trials researching immunotherapy treatments if that’s of interest to you.

The team at HealthPartners Cancer Care is ready to support you with personalized care and the latest innovations in cancer treatments. Throughout treatment, you’ll have a compassionate team of experts that includes oncologists, genetic counselors, surgeons, nurses, clinical trial researchers and many others.