Doctors have been fighting cancer for decades, but until now most treatment has been based largely on chemotherapy and surgery. One of the new avenues cancer researchers are exploring is CAR-T cell therapy, with the hope that it will provide more personalized treatment for cancer patients.
CAR-T cell therapy, sometimes described as a “living drug,” works by extracting the patient’s T cells, which are the cells that recognize and kill infected cells, and modifying them so they’re better able to fight cancer.
In order to create CAR-T cell therapy, some of the patient’s blood is taken and the T cells are separated and then genetically modified. Through the modification process, the cells produce receptors on their surface called chimeric antigen receptors, or CARs, which allow the cells to recognize and attach to a specific protein on the tumor cells. When the cells are reintroduced to the patient’s body, they multiply, recognize the cancer cells and then kill them.
As of 2017, two CAR-T cell therapies have been approved by the FDA as a standard treatment option, including one for the treatment of children with acute lymphoblastic leukemia (ALL) and the other for adults with advanced B-cell lymphoma (DLBCL). CAR-T cell therapy has expanded the range of options for patients who previously didn’t have many therapeutic choices. For example, those with ALL who suffered a relapse after intense chemotherapy or a stem cell transplant usually did not have another way to fight the disease, but CAR-T cell therapy can now offer them another highly effective option. The greatest challenge is managing the potential toxicities of these CAR-T therapies when given to patients with these blood cancers. Physicians are working diligently to try to apply CAR-T treatment to patients with solid tumors. So far, efficacy has been limited.