Chimeric antigen receptor T-cell therapy (CAR-T) is one of the most promising treatments for patients with certain forms of cancer. As scientists advance this ground-breaking technology, more people will hear about CAR-T therapy. It may take us beyond some standby treatments by helping to develop targeted therapies for patients with cancer.
What is CAR-T Therapy?
CAR-T therapy uses the body’s immune system to fight cancer. The immune system creates cells that fight illness naturally. It is the job of these T-cells to find things it doesn’t recognize. The immune system keeps track of everything generally found in your body. When something unusual pops up, it sends T-cells to investigate. CAR-T therapy uses this immunological process to identify and kill cancer cells.
How T-Cells Work
When the immune system recognizes foreign substances like viruses in the body, it creates antigens that attach to the surface of the cells. T-cells locate the danger and bind receptors to the antigens, triggering an immune system response to kill the invading cells.
The immune system keeps a record of the DNA of the invading cells. If the invading foreign body returns, it will recognize the DNA. Since it already has antibodies designed for that specific disease or microbe, it releases them to allow T-cells to find the invaders and destroy them.
This is the basis of vaccinations. They inject a small amount of inactive viral product into your body. That stimulates your immune system to create antibodies. So if you get that infection, your body is prepared to fight it.
How CAR-T Therapy Works
Cancer cells also have antigens; only the immune system doesn’t recognize them and deploy T-cells. CAR-T therapy takes t-cells from a patient’s blood and alters them in a lab. The goal is to add a gene, the chimeric antigen receptor, so that the T-cells will attach to the cancer antigens. They then inject these altered T-cells back into the patient, so they can locate cancer and trigger an immune response to destroy it.
In 2017, the Food and Drug Administration (FDA) approved several forms of CAR-T therapy to treat specific blood cancers, including:
- Lymphomas
- Some types of leukemia
- Multiple myeloma
CAR-T therapy is less than perfect. It only leads to the long-term survival of about half of the patient who gets the treatment. It can also have side effects. Patients typically experience flu-like symptoms such as:
- Fever
- Muscle aches
- Headaches
- Nausea
- Fatigue
It can also cause low blood pressure and trouble breathing. There is a risk of weakening the immune system, as well. The treatment is specific to each patient, making it costly, too.
The Future of CAR-T Therapy
Despite the challenges, researchers hope to improve how CAR-T therapy works over time. There are hundreds of ongoing clinical trials, including hopes to use this treatment against solid tumors one day. Research groups are using “armored” CAR-T cells in the hope of targeting tumors and using the immune system to destroy them. There has been some progress in this area, but it may be years before we see treatments readily available for cancer patients with tumors.
