A gene therapy treatment used in cancer patients is under scrutiny by the U.S. Food and Drug Administration (FDA) after the agency received reports of new blood cancers among treated individuals.
The treatment, CAR-T, was first approved by the FDA in 2017 and is used in the treatment of blood cancers. However, the agency has received “reports of T-cell malignancies”—a group of blood disorders—among some of the patients who received CAR-T treatments, according to a Nov. 28 announcement.
The reported malignancies include lymphoma, a cancer of the lymphatic system which includes lymph nodes, the thymus gland, bone marrow, and the spleen.
“Although the overall benefits of these products continue to outweigh their potential risks for their approved uses, FDA is investigating the identified risk of T cell malignancy with serious outcomes, including hospitalization and death, and is evaluating the need for regulatory action,” the agency said.
In CAR-T treatments, a type of white blood cells called T cells are removed from the blood of a patient. These cells are then genetically engineered to make proteins called chimeric antigen receptors (CAR).
The receptors allow T cells to attach to cancer cells and kill them. Once the genetic engineering is completed, the modified cells are then infused back into the patient’s blood, The New York Times reported.
The FDA pointed out that “patients and clinical trial participants receiving treatment with these products should be monitored life-long for new malignancies.”
“In the event that a new malignancy occurs following treatment with these products, contact the manufacturer to report the event and obtain instructions on collection of patient samples for testing for the presence of the Chimeric Antigen Receptor (CAR) transgene,” the agency said.
At present, the FDA has approved six CAR-T products:
Kymriah from Novartis
Yescarta from Gilead
Carvykti from J&J and Legend
Breyanzi from Bristol Myers Squibb
Abecma from Bristol Myers Squibb
Tecartus from Gilead
The risk for developing malignancies applies to all six products, the FDA said.
Medical experts did not expect the FDA’s recent announcement.
“In informal emails among many scientists and physicians in the field, we are all surprised by this announcement,” Marcela Maus, a researcher at Mass General Cancer Center, told health outlet STAT.