Have you ever heard of CAR-T? No, it’s not the kind of car you would drive down the road. CAR-T is a type of cancer immunotherapy that uses a patient’s own cells to destroy cancer cells in their body. CAR-T stands for the Chimeric Antigen Receptor that is placed on a cancer patient’s T cells. In this way, the cells can fight the disease!
Let’s look at how this works in more detail.
How does CAR-T therapy work?
T cells are in your blood and help you fight infections, viruses and ailments such as the common cold. T cells are strong, but not strong enough to target and kill cancer cells. To make them stronger, a cancer patient’s T cells must be extracted (taken out) and made into super-strong-cancer-fighting T cells called CAR-T cells.
In a hospital or doctor’s office, a medical assistant uses a technique called apheresis to take out only the T cells in a cancer patient’s blood. The assistant then returns other parts of the blood to the person’s body. Finally, the assistant sends the patient’s T cells off to a manufacturing site.
At the manufacturing site, a laboratory technician genetically engineers a patient’s T cells. They make changes that allow the T cells to produce many chimeric antigen receptors, or CARs. CARs help the T cells recognize a specific marker on cancer cells. These are no longer simple T cells that everyone has in their blood. They are CAR-T cells: super-strong-cancer-fighting T cells that can kick cancer’s butt! So now, all that’s left is for a medical assistant to infuse (put in) these CAR-T cells back into the patient. Then, those cells will start attacking the cancer!
Did you know? CAR-T is a type of personalized medicine because it uses a patient’s immune system cells to provide treatment of diseases.
CAR-T therapy in leukemia
Let’s put this all together using an example. Leukemia, which is cancer of the blood or bone marrow, is the most common type of childhood cancer in Canada. A specific type of leukemia called acute lymphoblastic leukemia (ALL) is usually treated with chemotherapy. But some patients do not respond to this treatment. Pharmaceutical companies (companies that research, manufacture and sell medicine) saw this as a problem. They decided to create a CAR-T therapy, called tisagenlecleucel, that could help these children.
First, the researchers isolated T cells from the children participating in the trial. Then, laboratory technicians genetically engineered the T cells with special CARs. These CARs were specifically engineered to recognize the protein CD19, which is found on all cancer cells.
After three months, doctors and nurses tested the patients who were treated with these CAR-T cells. Many of them went into remission after therapy. Some patients even had no signs of cancer!
CAR-T and the future
CAR-T has made many cancer treatments possible, and it’s a hot topic in cancer research. In 2017, the United States Food and Drug Administration (FDA) approved two CAR-T therapies. The FDA regulates food production, medicine, cosmetics and vaccines in the United States. Health Canada, which approves drugs and therapies in Canada, plans to have clinical trials of CAR-T therapies starting in mid-2018. Researchers at the B.C. Cancer Agency have ideas on how to improve CAR-T therapies and apply them to different types of cancer.
Scientists don’t have a cure for cancer yet, but with CAR-T and other types of therapies, they are certainly making progress!
Learn More!
Using Immune Cells to Fight Cancer (2015)
CurioCity by Let’s Talks Science
Immune System (2015)
Kids Health
What is Leukemia? (2018)
Canadian Cancer Society
Chimeric Antigen Receptor (CAR) T-Cell Therapy Facts (2016)
Leukemia and Lymphoma Society of Canada
References
Using Immune Cells to Fight Cancer (2015)
Anna Zhou, CurioCity
CAR T Cells: Engineering Patients’ Immune System to Treat their Cancers (2017)
National Cancer Institute
Canada Joins the CAR T-Cell Club (2017)
Michael MacRae, Alliance of Advanced BioMedical Engineering
Human T-Cell Isolation
Thermo Fischer Scientific
Childhood Cancer Statistics
Canadian Cancer Society
CAR T-Cell Therapy Approved for some Children and Young Adults with Leukemia (2017)
National Cancer Institute
Taking Personalized Medicine to a New Level (2017)
Martina McGrath, Harvard Medical Trends in Medicine
Novartis’ CAR T-Cell gene therapy, the first approved by the FDA, to cost $475,000 (2017)
Emma Court, Market Watch
T Cells
National Multiple Sclerosis Society
A Milestone for CAR-T Cells (2017)
Tran, E., Longo, D. L., Urba, W. J., The New England Journal of Medicine
What is CAR T?
Memorial Sloan Kettering Cancer Center
What is CAR T-cell Therapy?
Juno Therapeutics
With FDA Approval for Advanced Lymphoma, Second CAR T-Cell Therapy Moves to the Clinic (2017)
National Cancer Institute
Regulated Products (2018)
U.S. Food and Drug Administration
B.C. researchers working to bring ‘game-changing’ cancer treatment to Canada (2017)
Neetu Garcha, Global News
CAR-T Immunotherapy Cells (Image)
National Cancer Institute