Is the CAR T-Cell Revolution Here?

By Daniel K. Brantley
Friday, July 30, 2021
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A tailor-made oncology treatment, CAR T-cell therapy promises to transform cancer care. But can its potential overcome its problems?

In recent years, oncology researchers have been taken with chimeric antigen receptor (CAR) T-cell therapy. A novel therapeutic approach, CAR T-cell therapy relies on T cells, white blood cells found in the immune system that lead the immune system’s response, destroying pathogen-infected cells.

Currently, CAR T-cell therapy requires a blood draw from the patient to create an individualized treatment for that patient. The T cells are culled, genetically engineered to manufacture chimeric antigen receptors (CARs) and multiplied in the laboratory. When reintroduced into the patient’s body, the CAR T cells continue multiplying and begin to target and destroy cancerous cells with the chimeric antigen.

To add efficiency and economy to the process, researchers hope to modify a key component of CAR T-cell production. Instead of relying on patient cells, researchers are looking to have generic donors provide T cells. Should this prove efficacious, the door could open wide for this promising, new therapeutic methodology.

The Early Promise

CAR T-cell therapy was initially developed as a secondary treatment for acute lymphoblastic leukemia (ALL), a major cause of childhood cancer-related death. Prior to the advent of CAR T-cell therapy, no therapy was available for recurrent cases of ALL. Once CAR T-cell therapy was deemed safe and effective in these cases, it gained approval from the FDA for use in children before getting approved for adult usage, a rarity in cancer care.

Since deemed efficacious in treating ALL, it was found beneficial when treating adult lymphoma. And whereas CAR T-cell development once required weeks, time from blood draw to infusion is now down to as little as a week. By using generic donors, this time could drop even more.

With such progress, many suspect CAR T-cell therapy, once deemed a boutique treatment, could become a common treatment for lymphoma and other cancers. One such optimist is immunotherapy forerunner Steven Rosenberg, MD, PhD, Chief of the National Cancer Institute’s (NCI) Center for Cancer Research Surgery Branch. His laboratory team documented the premiere CAR T-cell therapy success.

“In the next few years,” he says in an article on the NCI website, “I think we’re going to see dramatic progress and push the boundaries of what many people thought was possible with these adoptive cell transfer-based treatments.”

The Potential Problems

Though full of potential, CAR T-cell therapy has an uphill road to broader use. One is a common, potentially fatal side effect: cytokine release syndrome. This syndrome can be managed with steroids and other support therapies, but because it indicates treatment is working, it may not be totally unavoidable. Additionally, it is unknown whether generic CAR T-infused cells will result in graft-versus-host disease or immune rejection.

While seeking answers to these questions, researchers also hope to learn whether CAR T cells offer effective treatment against solid cancers. Early studies say no. But ongoing research aims to disprove this and eventually lead to a new tool in the fight against cancer.