Comprehensive Interpretation of CAR T-Cell Therapy

CAR-T (Chimeric Antigen Receptor T-Cell), which stands for chimeric antigen receptor T-cells, is a process where a person’s T cells are genetically engineered outside the body to be modified, giving them the ability to recognize and efficiently kill cancer cells before being re-infused into the patient’s body, thereby achieving the goal of treating malignant tumors.
In fact, CAR-T therapy is not only used for treating cancer but also holds great potential in the fields of autoimmune diseases, chronic infections, heart disease, and age-related diseases.
T cells, also known as T lymphocytes, are the main components of lymphocytes and are primarily responsible for immune responses and disease defense. They have functions such as directly killing target cells, assisting and inhibiting B cells to produce antibodies, responding to specific antigens and mitogens, and producing cytokines.
Of course, the human immune system is not limited to T cells; it also includes B cells, neutrophils, K cells, NK cells, and more. They play roles in clearing waste metabolic products from the body, recognizing and producing antibodies, and identifying and killing foreign pathogens and cancer cells.
Since T cells already have the function of recognizing and killing cancer cells, why is it necessary to artificially add CAR to T cells to create CAR-T cells to kill cancer cells? This brings us to the concept of immune evasion, which is one of the most fundamental characteristics of cancer.
CAR-T therapy, or CAR-T cell therapy, involves separating the patient’s T cells, expanding them outside the body, and then introducing an artificially designed tumor cell antigen CAR (chimeric antigen receptor) to the T cells. After processing, the anti-tumor activity of T lymphocytes is significantly enhanced before being re-infused into the patient’s body, thus restoring the T cells’ ability to recognize and kill cancer cells. This is the essence of CAR-T cell therapy.
Impact Bio’s CAR-T therapy IMPT-514 receives FDA approval.
On August 21, 2024, Impact Bio announced that the FDA had approved its IND application for the IMPT-514 therapy it developed. IMPT-514 is a bispecific CD19/CD20 CAR-T therapy used to treat active refractory systemic lupus erythematosus (SLE). In clinical trial data, IMPT-514 was shown to be highly efficient in producing from patients with severe immunosuppression from various autoimmune diseases, and it demonstrated potent autologous B-cell clearance capabilities with a mild cytokine profile. Axicabtagene ciloleucel CAR-T therapy for large B-cell lymphoma still shows sustained response after five years. On August 2, 2024, the American Society of Clinical Oncology (ASCO) released a data report on long-term survival rates following CAR-T cell therapy. The results showed that among patients who underwent CAR-T therapy, the 5-year progression-free survival rate was 29%, the 5-year overall survival (OS) rate was 40%, and the 5-year lymphoma-specific survival rate was 53%, with rare late relapses. Axicabtagene ciloleucel is an autologous CD19 chimeric antigen receptor CAR-T cell therapy approved for the treatment of relapsed or refractory large B-cell lymphoma. Conclusion: In a standard care setting, the treatment outcomes of axicabtagene ciloleucel CAR-T are consistent with the results reported in clinical trials, with sustained, durable responses observed at the 5-year mark.
World’s first successful CAR-T treatment for autoimmune disease.

On October 4, 2024, the Nature website headlined a report introducing a research outcome from a Chinese team. Scientists used CRISPR-Cas9 gene-editing technology to genetically engineer healthy donor-derived CAR-T cells targeting CD19, developing a new generation of allogeneic universal CAR-T therapy that helped three patients with severe autoimmune diseases achieve long-term remission.