(WISH) — In 2017, the FDA approved the first CAR T-cell therapy. Medical experts call it a ‘breakthrough’ and ‘gamechanger’ when it comes to cancer treatment. Now, it’s issuing a warning.

Dr. Frederick Locke, MD, Dir., Immune Cell Therapy Program at Moffitt Cancer Center says, “Immunotherapy has really come on as quite an advance in cancer care.”

CAR T-cell therapy is a type of cellular immunotherapy used for patients with certain types of leukemias and lymphomas, as well as multiple myeloma. It uses the patient’s own immune system cells to attack cancer cells.

Locke says, “The blood comes out. It goes through a machine that removes the T-cells that we are interested in, and the blood is returned to the patient.”

The T-cells are then sent to a lab to be engineered into car T-cells. After a few weeks, they are returned to the patient’s bloodstream, where they can find and destroy the cancerous cells.

“We are actually taking the cells out and reprogramming them to get the strongest response possible from these chimeric antigen receptor T-cells, or CAR T-cells.” explains Locke.

Studies show positive response rates with CAR T-cell therapy, with many patients entering remission, and survival rates going up.

But now the FDA is investigating reports of T-cell cancers in people who had the treatment… with outcomes including hospitalizations and death. The FDA is instructing the manufacturers of these therapies to add a boxed warning – its highest safety-related warning. It says patients and clinical trial participants should also be monitored for new cancers.

Despite the warning, the FDA says it has no concern about continued use of this therapy, saying “The overall benefits of these products continue to outweigh their potential risks for their approved uses.”

As of the end of 2023, more than 27 thousand people in the US have received the CAR T-cell therapy. The FDA says it has received about 22 reports of cancers following the treatment.

This story was created from a script aired on WISH-TV. Health Spotlight is presented by Community Health Network.