T-cells are taken from a patient’s blood. Then the gene for a special receptor that binds to a certain protein on the patient’s cancer cells is added in the laboratory. The special receptor is called a chimeric antigen receptor (CAR). Large numbers of the CAR T-cells are grown in the laboratory and given to the patient by infusion. Each CAR is specifically manufactured for each patient. CAR T-cell therapy is being used for diffuse large B-cell lymphoma (DLBCL) on the NHS and is being studied in the treatment of some types of cancer.
CAR therapy can cause prolonged toxicities because the engineered T-cells can persist in the body even after treatment is no longer required. These immune reactions are usually treated with steroids or neutralizing antibodies but can be fatal in some cases. Neurologic toxic effects have also been reported, including confusion, hallucinations, and seizures, as well as increased risk of infections.
CAR engineering is still being perfected, and once optimised through further clinical trials, will offer an attractive treatment approach for B-cell malignancies. It can be used as a conduit to stem cell transplantation or as a solo potentially curative therapy for relapsed / refractory diseases. By ensuring the proper connection of active agents to effector T-cells, CAR therapy bypasses several potential points of resistance in relapsed / refractory diseases.