Unlike the more conventional treatments, which use drugs or radiation to destroy cancer cells, immunotherapy works with the body’s immune system to fight cancer by:
- Stimulating the patient’s own immune system to work harder or smarter to attack cancer cells.
- Treating the patient with immune system components, such as man-made immune system proteins.1
Cancer immunotherapy takes many different forms, including...
- Monoclonal antibodies (mAb) – Drugs which bind to specific proteins in the body, inciting an immune response which kills cancer cells or “marks” them for a subsequent immune response.2 These drugs are highly specific, so cells without the proteins are not affected. Examples include:
- Rituximab – for some types of non-Hodgkin’s lymphoma
- Herceptin – for some forms of early breast cancer
- Vaccines – Some vaccines prevent viruses that can cause cancer (e.g. Gardasil, Cervarix for prevention of HPV and subsequent cervical cancer). Others treat cancer, itself, by boosting the immune system’s response to cancer cells (e.g. Provenge for advanced prostate cancer patients)
- Adoptive cell transfer (ACT) – Immune cells are removed from a patient’s body, re-engineered to learn to attack cancer, and then re-infused into the patient’s body.3
- Immune checkpoint inhibitors (ICI) – Treatments that target the molecules (checkpoints) on certain immune cells that need to be activated (or inactivated) to start an immune response.4 Examples of immune checkpoint inhibitors include Yervoy, Keytruda and Opdivo for metastatic melanoma.
- Non-specific cancer immunotherapies and adjuvants – Treatments that stimulate the immune system in a less direct way, but still help to boost the immune response against cancer cells. Some of these are given as cancer treatments, and some are used as adjuvants to improve the response to another immunotherapy, such as a vaccine.5 Examples of these include cytokines, which are signaling proteins produced by white blood cells and help mediate and regulate the immune response.
While monoclonal antibodies and some vaccines have been in use for a number of years now, it’s still relatively early days for adoptive cell transfer and immune checkpoint inhibitors. But emergent success has generated great excitement and hope for these promising new therapies. As Dan Chen, head of Genentech’s immune checkpoint inhibitor program, put it, “Our real hope is that we can take a terminal disease and for some, at least for now, provide them with long-term survival.” “The promise of immunotherapy is that we see patients with a much more durable response, who are alive two, three, five, ten years on.”6 Exciting times, indeed.
1 What is cancer immunotherapy? American Cancer Society website.
what-is-immunotherapy Accessed January 7, 2016.
2 Immunotherapy. National Cancer Institute website http://www.cancer.gov/about-cancer/treatment/types/immunotherapy Accessed January 7, 2016.
3 Immunotherapy: Disrupting the Cancer Treatment World. American Cancer Society website.
world Accessed January 7, 2016.
4 Immune checkpoint inhibitors to treat cancer. American Cancer Society website.
immunotherapy-immune-checkpoint-inhibitors Accessed January 7, 2016.
5 Non-specific cancer immunotherapies and adjuvants. American cancer society website. http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/cancer-
immunotherapy-nonspecific-immunotherapies Accessed January 10, 2016.
6 Guha, M. The new era of immune checkpoint inhibitors. The Pharmaceutical Journal.
hope-to-cancer-patients/20067127.article Accessed January 10,2016.