CAR T-cell Therapy Received Approval

The five-year survival rate for children with Acute lymphoblastic leukemia (ALL) has increased up to 85%. This number; however, is expected to increase even further with the approval of CAR T-cell immunotherapy.  Briefly, chimeric antigen receptor (CAR) T-cells are white blood cells that are extracted from a patient and then treated at a special laboratory. These treated T-cells are then reintroduced into the patient’s body to fight cancer cells. So far, trails on kids with ALL were successful with high rates of remission. CAR T-cell therapy is making history by being the first gene therapy approval in the U.S.

You may be asking yourself what ALL is and how this occurs? Stem cells develop into different blood cells such as RBC, WBC, and platelets. These stem cells are in the bone, specifically in spongy bone. ALL is a cancer of stem cells and these cancer cells multiply rapidly, eventually overcrowding normal healthy cells. The multiplication of these cancer cells decreases the production of healthy lymphocytes to fight infection. These stem cells are in the bloodstream; thus, being able to metastasize.   In adults ALL is a rare disease with poor prognosis, and patients over the age of 60 have a 5-year survival rate of 30-40%. In cases of relapse, the survival rate decreases to only 6 months. However, in children ALL is the most common malignancy of childhood and has a high cause of death from cancer in children (Singh et al., 2016).

The immune system helps defend the body against disease and one of those cells (T-cells) are the cells soldiers. CAR T-cells are engineered cells that belong to a patient’s immune system to become better and smarter at attacking a target. So, how does this process occur? This process occurs by separating the T-cells from other white blood cells (WBC) using a machine (located in a factory in New Jersey). The CAR T-cells then become infected with a disabled virus that has genetic information that will allow the T-cell to grow a specific receptor called chimeric antigen receptor, hence the name CAR T-cell. These CAR T-cell receptors aide the T-cell to locate the targeted antigen. Millions of these CAR T-cells are then reinserted into a patient’s body via IV. Once in the blood stream, CAR T-cells locate the targeted antigen and release chemicals into targeted cell causing apoptosis of cancer cell. The target of interest is CD19. CAR-T cells become modified against CD19 which possesses high attributes of expression on B cell cancers, but restricted expression on normal B cells (Aldoss et al., 2017). 

What are current therapies against ALL? Chemotherapy, radiation therapy, biologic therapy, and bone marrow transplantation. How does CAR T-Cell immunotherapy compete with current therapies in an economic aspect?  Transplantation can be anywhere between $800,000. So, what is the cost for this CAR T-cell immunotherapy? The U.S government has indicated that this treatment is a one-time treatment of $475,000. However, payment is required if the child is in remission at one month. So, you only pay if it works. What are the risks? The risks are that you produce a cytokine storm which means that many cells are being killed off at once. Side effects common to this treatment are high fever, vital infection, and immune signaling.

Where else can this therapy be used? Soon, CAR T-cell immunotherapy will be used for adult leukemia/lymphoma. However, there is potential in using this therapy in other cancers, diabetes, HIV, heart and autoimmune diseases, and genetic disorders. In summation, we the approval of CAR T-cell immunotherapy, there is hope of further increasing survival rate and remission rate of children with ALL.

Aldoss, I., Bargou, R. C., Nagorsen, D., Friberg, G. R., Baeuerle, P. A., & Forman, S. J. (2017). Redirecting T cells to eradicate B-cell acute lymphoblastic leukemia: bispecific T-cell engagers and chimeric antigen receptors. Leukemia, 31(4), 777-787. doi:10.1038/leu.2016.391

Singh, N., Frey, N., Grupp, S., Maude, S., Frey, N. V., Grupp, S. A., & Maude, S. L. (2016). CAR T Cell Therapy in Acute Lymphoblastic Leukemia and Potential for Chronic Lymphocytic Leukemia. Current Treatment Options In Oncology, 17(6), 1-11. doi:10.1007/s11864-016-0406-4

http://www.huffingtonpost.com/entry/7-amazing-medical-breakthroughs-that-will-wow-the-world-in-2017_us_5852c870e4b012849c05d133

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