CAR T Cell Therapy: A Discussion of the Emerging Cancer Treatment

You may be wondering what CAR T Cell therapy is, right? To explain how the therapy works, let me first explain what T cells are. T cells are a type of lymphocyte, a form of white blood cells that play a role in your body’s adaptive immunity. T cells mature in the thymus, and are typically found in lymph nodes, other lymphatic tissues, or circulating in the blood. On their surface, T cells have receptors that only recognize specific epitopes, which are a specific part of antigens that are recognized by antibodies, B cells, and T cells that often triggers an immune response. The fact that the T cell receptors only recognize specific epitopes is an important piece of how different T cell therapies work, as T cells can be modified to respond to the specific epitopes we need it to respond to.

Because T cells can be found in the blood, T cells are collected through a process in which blood is collected from a patient, the T cells are separated and removed from the blood, and then the rest of the blood is put back into the patient’s body. From there, the T cells are brought to a lab where they are altered to have a special type of receptor, a chimeric antigen receptor, or CAR for short. The chimeric antigen receptors help to improve T cell recognition of cancer cells, which helps the T cells become activated and kill the cancer cells. In other types of T cell therapy, they still alter the T cells but they alter them to have whatever kind of receptor they need for their purpose. After the T cells are altered to have the CAR, they are grown in the lab so that lots of the T cells are produced. These CAR T cells are then introduced back into a patients body after the patient undergoes chemotherapy, and the CAR T cells continue to multiply and attack the cancerous cells in the body. Once in the body, the CAR T cells can continue to circulate and multiply, which means that they can also help fight any returning cancer and can help to keep cancer patients in remission.

While this does sound like a great way to treat cancer, it is also important to note that this type of treatment is very new. At this time, this therapy is mainly being used to treat lymphoma and certain blood related cancers. There are a lot of different side effects of the treatment including neurological issues, anemia, neutropenia, and cytokine release syndrome, which can cause all kinds of issues in the body and in some cases can be life threatening. In addition, in order to treat some of these side effects, the patient would need to take more drugs which may have additional side effects. Because it is a newer treatment and requires a lot of equipment and work, the CAR T cell therapy can be extremely expensive, with one website estimating that it could cost as much as $375,000 for treatment, not including other related expenses. While there still isn’t information on the long term success of the treatment, patients in clinical trials have seen an 80% complete or partial response rate, meaning some or all of their cancer cells have been killed, and an 80% remission rate. Overall, there are unfortunately a lot of side effects and associated costs for this treatment, and while this is new kind of treatment, the idea of the treatment certainly shows a lot of promise.

Featured image by National Cancer Institute on Unsplash.