Using T cells to fight cancer
Chimeric antigen receptor T cell therapy (CAR-T cell therapy) is a form of immunotherapy that uses T cells, a type of immune cell often referred to as the workhorses of the immune system, to fight cancer.
After taking T cells from a patient’s blood, a synthetic receptor called a chimeric antigen receptor (CAR) is added to T cells in the lab, and the cells are then multiplied.
Sometimes talked about as a type of cell-based gene therapy, these new CAR-T cells are then infused back into a patient’s body to target specific antigens (the cells that stimulate an immune response) on the surface of cancer cells.
How CAR-T cell therapy works
The immune system can recognize foreign elements in the body by looking for antigens on the surface of those cancer cells. Each immune cell (the T cells) in a patient’s body has its own protein called a receptor that attaches itself to foreign antigens, triggering the immune system to destroy the foreign element.
The relationship between antigens and receptors is like two pieces of Velcro—similar to how you have to have the right side of the Velcro to make it stick, each foreign antigen has a unique immune cell receptor that can bind to it.
Cancer cells have antigens, but if a patient’s T cells don’t have the right receptors for that antigen, they can’t attach themselves to it and destroy the cancer cells.
In CAR-T cell therapy, T cells are taken from a patient’s blood and are reworked in the lab by adding a gene for a lab-created receptor called a chimeric antigen receptor (or CAR). These new CAR receptors given back to the patient better help them search for and identify those cancer cell antigens.
Since different cancer types have different antigens, each CAR created is made for a specific cancer’s antigen. CAR-T cell therapies used to treat leukemia or lymphoma, for example, may not work for other cancers like skin cancer or breast cancer.
How effective is CAR-T cell therapy?
Research, including hundreds of studies and clinical trials, is being done daily across the United States to investigate CAR-T cell therapy in many types of cancer.
Baylor Scott & White Health has one of the top cancer centers for immunotherapy and is changing the way cancer is treated in Texas by leading the first in human trials involving cellular therapies and the first approved site for adult commercial CAR-T cell therapy in North Texas.
The Food and Drug Administration approved the first CAR-T cell therapy in 2017, so much research is still to be done in regards to how well the therapy works.
Current research shows that CAR-T therapy is effective for blood cancers such as lymphoma or leukemia, but little data is shown for its effectiveness in solid tumors such as lung cancer or breast cancer as solid tumor antigens are harder for CAR-T cells to identify because they are typically on healthy tissue.
What to expect during CAR-T cell therapy
Step 1: Collecting the T cells
The first step of CAR-T cell therapy is taking blood from a patient and removing the white blood cells, which include T cells. This procedure is called leukapheresis and typically requires a patient to lie in a bed or sit in a reclining chair while two IV lines are administered—one to remove the blood and the other to separate out the white blood cells.
After separation, the blood is put back into the body through the original line it was taken out of.
The cancer patient will need to stay seated or lying down for two to three hours during the CAR-T cell therapy procedure.
Step 2: Creating the CAR-T cells
Once the white blood cells are removed, the T cells are then separated and sent to a lab where they are altered by adding the gene for the cancer-specific CAR. This process creates CAR-T cells, which are then grown and multiplied in the lab setting.
This part of the CAR-T cell therapy process may take several weeks to create a large volume of CAR-T cells needed for effective cancer treatment.
Step 3: The CAR-T cell infusion
Once the right volume of CAR-T cells have been created, they will be returned to the patient via infusion.
Some patients scheduled for CAR-T cell therapy may receive chemotherapy a few days prior to the infusion to help lower the number of other immune cells, giving the new CAR-T cells a better chance to get activated to fight the cancer cells.
After the cancer patient’s infusion, they will be watched closely for several weeks after receiving the CAR-T cells in case there are any side effects to monitor.
CAR-T cell therapy side effects
During the collection of T cells through leukapheresis, some patients may experience numbness, tingling or muscle spasms due to a drop in blood calcium levels. This can easily and quickly be treated by replacing the calcium, either orally or through an IV.
Additionally, cancer patients undergoing CAR-T cell therapy may experience other symptoms such as cytokine release syndrome (CRS), allergic reactions or effects on the nervous system.
Other side effects of CAR-T cell therapy
CAR-T therapy can also have serious effects on the nervous system, resulting in symptoms like:
- Confusion or agitation
- Trouble speaking or understanding
- Loss of balance
Additionally, other side effects can include symptoms such as allergic reactions during the infusion, a weakened immune system, low blood cell counts or abnormal levels of minerals in the blood.
It’s important to report any and all symptoms or side effects a patient experiences right away to their physician, as there are often treatments to help manage.
Cytokine release syndrome (CRS)
After infusion and the CAR-T cells begin multiplying, there is a chance of a patient developing cytokine release syndrome (CRS) due to a release of large amount of chemicals known as cytokines into the blood. These cytokines can ramp up the immune system, creating side effects such as:
- Flu-like symptoms, such as high fever, chills, and body aches
- Trouble breathing
- Severe nausea, diarrhea or vomiting
- Feelings of dizziness or lightheadedness
- Rapid heartbeat
We are a destination center for immune therapy in cancer care
Finding comprehensive immunotherapy for cancer can feel complicated. Baylor University Medical Center, part of Baylor Scott & White Health, in Dallas is a destination center for immune therapy in cancer care, offering patients access to clinical trials and advanced treatment options that utilize these living drugs to treat the most complex forms of cancer. Pioneering research and treatment in immunotherapies, Baylor University Medical Center is one of the first North Texas providers to offer adult commercial use of chimeric antigen receptor T-cell therapy (CAR-T cell therapy) to treat patients with large B-cell lymphoma and acute lymphoblastic leukemia.
The innovative therapies produced at Baylor Scott & White Research Institute’s Good Manufacturing Practice Core lab (cGMP) at Baylor University Medical Center combine with the comprehensive cancer care Charles A. Sammons Cancer Center – Dallas to provide a single destination of cancer care to make your journey of healing easier and more streamlined.
We continue to research and advance numerous other immunotherapies every day. For fighters like you, this means access to clinical trials you won’t find elsewhere and even more hope to destroy cancer.
You have access to multiple cancer care centers in Texas, including centers specializing in immunotherapy and CAR-T cell therapy. Get started by finding a CAR-T therapy location near you.