On Feb. 2, 2022, a new analysis of the first two patients treated in a clinical trial with CAR T cell therapy explains the longest persistence of CAR T cells recorded to date against chronic lymphocytic leukemia and shows that the CAR T cells remained detectable at least a decade after infusion, with sustained remission in both patients.

Called Chimeric Antigen Receptor (CAR) T cells, these genetically modified tumor-targeting cells are a living drug made for each patient out of their own cells. CLL, the first cancer in which CAR T cells were studied and used at Penn, is the most common type of leukemia in adults. While treatment of the disease has improved, it remains incurable with standard approaches. Eventually, patients can become resistant to most therapies, and many still die of their disease. The study was published in Nature.