Understanding Immunotherapy

Types of cancer immunotherapy

There are several types of immunotherapy, and they work in different ways in cancer treatment. Understanding how the different types of treatment work can help patients make a decision about their treatment approach with their healthcare professionals. Listed below are some common types of immunotherapy.

Immune checkpoint inhibitors

T-cells in our immune system have proteins on them that turn on an immune response and other proteins that turn it off. These are called checkpoints.10 Immune checkpoint inhibitors blocks proteins that stop the immune system from attacking the cancer cells.10

How they work11

This type of immunotherapy works by blocking checkpoint protein present on immune cells and tumor cells. Checkpoint proteins, such as PD-1, PD-L1 and CTLA-4, help keep immune response in check and could stop T-cells from removing cancer cells. An example of this is the binding of PD-L1 on tumor cells to PD-1 on T-cells could stops T-cells from killing the tumor cells in the body. By blocking the binding with an immune checkpoint inhibitor, the T-cells restore its function and allowing it to more effectively destroy tumor cells.

How they are used

Immune checkpoint inhibitors are used to treat a variety of cancers, such as skin cancer, non-small cell lung cancer, bladder cancer, and Hodgkin lymphoma.16 To know more about how checkpoint inhibitors are used in lung cancer and bladder cancer, please see Immunotherapy for lung cancer and Immunotherapy for bladder cancer sections for more information.

Immune checkpoint inhibitors are usually given by an intravenous infusion.16 Whether a patient can have this treatment depends on his or her type of cancer and might also depend on:

  1. The stage of cancer;
  2. Whether the patient has already had certain treatments.16

Patients should ask their doctor if this treatment is suitable for them.

PD-L1 testing:

FFor certain types and stages of cancers, testing for PD-L1 expression can help doctors inform better treatment options.12 This testing does not apply to all checkpoint inhibitors.10 Consult your doctor on whether PD-L1 testing applies to you.

Monoclonal antibodies7

Monoclonal antibodies, also known as therapeutic antibodies, are immune system proteins created in the lab. These antibodies recognize and attach to specific proteins found on cancer cells. Monoclonal antibodies work by marking cancer cells, so the immune system can better recognize and destroy the cancer cells, stop cancer cells growth, or initiate cell death. Monoclonal antibodies are used to treat a wide variety of cancers.


Cytokines are a group of proteins found in the body that play an important part in boosting the immune system. Man-made versions of these proteins, such as interferon and interleukin, have been developed as a treatment for cancer. Interferons and interleukin interfere with the way cancer cells grow and multiply, stimulate the immune system and encourage killer T-cells and other cells to attack cancer cells, and encourage cancer cells to produce chemicals that attract immune system cells to them. They can be used to treat kidney cancer, melanoma, multiple myeloma, and some types of leukemia.

Cancer vaccines5

Cancer vaccines treat cancers by strengthening the body’s natural defenses against cancers that are already developed. They are intended to help delay or stop further growth of a cancer, to prevent a cancer from coming back, or to destroy any cancer cells left behind after other treatments. The idea behind cancer treatment vaccines is that introducing one or more cancer antigens into the body will cause an immune response that ultimately kills the cancer cells. Therapeutic cancer vaccines currently available are used to treat prostate cancer.

Adoptive cell transfer

(also called adoptive T-cell therapy or immune cell therapy)

This type of immunotherapy is still quite new, and researches are being conducted to look into how well it works as a treatment for cancer.14 Adoptive cell transfer boosts the natural ability of an individual’s T-cells to fight cancer. In this treatment, T-cells are extracted from patients, grown and modified in the lab then re-administered back in the patients.15 The three current approaches to adoptive cell transfer are:15

  • Multiply collected T-cells;
  • Genetically modify T-cells to attack antigen on cancer cells; or
  • Equip T-cells with chimeric antigen receptors, this approach is called CAR-T therapy.

Currently, this type of immunotherapy is being used to treat non-Hodgkin lymphoma and certain types of acute lymphoblastic leukemia.15