How does CAR T-cell therapy work?
The process begins by collecting blood from the patient with cancer. During this process, T cells are separated and removed from the blood and the remaining blood is returned to the body. This procedure is called leukapheresis or apheresis and is similar to the process of giving certain types of blood donations. T cells, which are a type of white blood cell of the immune system, are the body’s primary killing cells. They protect the body by destroying abnormal cells, including cancers.
Sometimes, however, T cells don’t recognize cancer cells or cannot fully destroy all of them in the body. To improve the cancer-killing ability of T cells, the next step is to genetically alter them. This is done in a special laboratory. The altered T cells now have special receptors on their surface. These new receptors, called chimeric antigen receptors (CAR), allow the T cells to better recognize cancer cells, become activated, and kill their target. These altered T cells are now called a chimeric antigen receptor (CAR) T cells. The CAR T cells are then grown in a special laboratory until millions are produced.
Next, the patient receives a brief course of chemotherapy, which improves the chance that the new CAR T cells will be accepted and not attacked by the immune system when returned to the body. Finally, the CAR T cells are delivered back into the patient through an infusion into the patient’s bloodstream. Once in the body, the CAR T cells continue to multiply. The CAR T cells attach to a specific structure, called an antigen (most commonly a protein called CD19), on the surface of the targeted cancer cells. Once attached, the T cells become activated and release toxins that kill the cancer. The CAR T cells remain in the body for a long time after the infusion, helping to fight cancer if it returns and keep the patient in remission.
How long does the patient remain in the hospital following CAR T-cell therapy?
Patients typically need to stay in the hospital one to one and one-half weeks after receiving CAR T-cell therapy. Length of stay depends on many factors including the patient’s response to treatment and the risk for side effects.