CAR T-cell therapy represents a groundbreaking approach to harnessing the power of the body's immune system to combat cancer. By modifying T cells, a subset of white blood cells, in a laboratory setting, these cells are empowered to recognize and eliminate cancer cells with precision. Often categorized as a form of cell-based gene therapy, CAR T-cell therapy involves altering the genetic makeup of T cells, equipping them with the ability to target specific cancer antigens.

This innovative treatment has demonstrated remarkable efficacy, particularly in cases where conventional therapies have proven ineffective. Its ability to reprogram the immune system to target and destroy cancer cells marks a significant advancement in cancer treatment strategies.

Classification:

CAR T cell therapy is classified as follows:

• Structure-based classification:
• First-generation CAR T-cells: These CAR T-cells typically consist of an antigen-binding domain (single-chain variable fragment, scFv) linked to a T-cell activation domain, such as the CD3ζ chain. They lack additional co-stimulatory domains.
• Second-generation CAR T-cells: These CAR T-cells include an additional co-stimulatory domain, such as CD28 or 4-1BB (CD137), along with the CD3ζ chain. The presence of co-stimulatory domains enhances T-cell activation and persistence.
• Third-generation CAR T-cells: These CAR T-cells incorporate two co-stimulatory domains along with the CD3ζ chain, aiming to further enhance T-cell function and anti-tumor activity.

Antigen-based classification: It includes

• CD19-targeted CAR T-cells: CD19 is a common target for CAR T-cell therapy and is used in the treatment of B-cell malignancies such as acute lymphoblastic leukemia (ALL) and certain types of lymphoma.
• Other antigen-targeted CAR T-cells: CAR T-cells can be engineered to target a variety of antigens expressed on cancer cells, including but not limited to BCMA (B-cell maturation antigen), CD22, CD30, and EGFRvIII.