CAR T cell  ( Chimeric Antigen Receptor T Cell) immunotherapy approved by FDA (US Food and Drug Administration) will revolutionize cancer treatment. This is the first time approval being given to use gene editing to treat disease in the United States. For now, the therapy ((named Kymriah by Novartis), is approved to treat children and young adults (up to age 25) with a recurrent form of the blood cancer called acute lymphoblastic leukemia (ALL).

This therapy is unique and customized: Each patient's own cells are re-engineered in a lab to fight cancer and sent back into their bodies to go to work. With more research and clinical trials, which are currently ongoing, this personalized therapy has the potential to treat a wide variety of blood and solid tumor cancers.

It involves removing some T-cells—a type of white blood cell—from a patient's blood. Then researchers tweak the outside of each cell in the lab by adding a receptor called CAR (chimeric antigen receptor). When the altered T-cells are infused back into the body, these receptors help them find and kill cancer cells.

CAR T-cell therapy was invented by a group of scientists, including Dr. Carl June from the University of Pennsylvania, about a half decade ago. It hit the public eye when doctors used it on a young girl named Emily Whitehead, a then six-year-old with a relapsed and aggressive form of ALL. The experimental treatment worked—Emily is now 12 and cancer-free—and sparked a number of clinical trials and partnerships with drug companies, including Novartis.

These engineered cells used as drugs are so good at finding and attacking leukemia cells that are often called "killer T-cells." Dr. Carl June, in an interview, recalled one patient who didn’t see improvement until about one month after he received his engineered T-cells. Then, all of a sudden, his condition improved drastically. When doctors traced which T-cells were involved, they found that every engineered CAR T-cell in his body had descended from just one single transfused cell. "We infused 100 million into him," said June, "and just one of them did all the heavy lifting."

Traditional therapies like chemotherapy and radiation only target the cancer cells and tumors. You need different types of drugs depending on the type of cancer, and once you stop giving a person the treatment, it quickly leaves the body or stops working. CAR T Cell treatment, and all immunotherapies to a certain extent, target the person’s immune system and harness it to fight the cancer. In theory, it works just like a vaccine: once the immune system is coaxed into fighting the unhealthy cells, it should keep fighting them for a lifetime. That's the idea, anyway—there's still a lot of research to do.

The therapy is not without its dangers. One of the biggest obstacles doctors and researchers face is handling the immune response that comes with the treatment. Almost all side effects that occur with other immunotherapies can occur in CAR T Cell therapy also. More research and studies are needed to expand this novel therapy in other cancerous conditions.