March 11-17, 2019
By Nan Selz
Executive Council, AARP Arkansas
Engineering patients’ own cells to treat some cancers
Traditionally, cancer has been treated by surgery, chemotherapy and radiation therapy. More recently, the use of drugs that target cancer by honing in on specific molecular changes seen primarily in cancer cells have joined those standard treatments.
Now immunotherapy has emerged as a fourth option for treating cancer. Immunotherapy uses the strengthened power of the patient’s own immune system to attack the disease. The latest immunotherapy approach, called adoptive cell transfer and abbreviated as ACT, collects and uses the patients’ own immune cells, called T-cells, to treat their cancer. There are several types of ACT, but the most advanced in clinical development is called CAR T-cell therapy. CAR T-cell therapy is also called chimeric antigen receptor T-cell therapy.
In CAR T-cell therapy, T-cells are taken from a patient’s blood. The gene for a receptor that binds to a protein on the patient’s cancer cells is added to the T-cells 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.
Until recently, the use of CAR T-cell therapy was restricted to small clinical trials, largely in patients with advanced blood cancers. These treatments have achieved remarkable results in some patients for whom all other treatments had stopped working.
In 2017, two CAR T-cell therapies were approved by the Food and Drug Administration, one for the treatment of children with acute lymphoblastic leukemia and the other for adults with advanced lymphomas. Questions remain, however, about whether these therapies will be effective against solid tumors like breast and colorectal cancer.
Different types of ACT “are still being developed,” said Steven Rosenberg, M.D., Ph.D., chief of the Surgery Branch in the National Cancer Institute’s Center for Cancer Research, an immunotherapy pioneer whose lab was the first to report successful cancer treatment with CAR T-cells. “In the next few years,” he said, “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.”
Research continues into the benefits of stem cell therapies. While the FDA has approved the use of stem cells for some limited treatments, caution is advised in seeking such treatments since these therapies are still being developed and are not indicated for all types of cancer.
AARP has much more information on breakthroughs in cancer treatment at https://www.aarp.org/health/conditions-treatments/info-2017/newest-cancer-treatment-technology.html