In 2012, 6-year-old US-American Emily Whitehead was hopeless. Her parents didn't know what else to do. The little girl was battling acute lymphoblastic leukemia, the most common form of childhood cancer, but the standard treatment that works for the vast majority of children had no effect on Emily. Her illness was so out of control that she wasn't even eligible for a bone marrow transplant. It was then that the doctors informed Emily's parents that there was nothing more they could do to save her.
But Tom and Kari Whitehead didn't give up. They had heard that at the Children's Hospital of Philadelphia, a pediatric oncologist was investigating a completely new way to treat cancer. In collaboration with researchers at the University of Pennsylvania, Dr. Stephan Grupp was researching a revolutionary approach called CAR-T cell therapy.
Then in an experimental phase, CAR-T therapy makes use of modified body defense cells, T lymphocytes, which express the chimeric antigen receptor (CAR) on their surface. This therapy harnesses the power of the patient’s own immune system by reshaping their T cells, making them capable of finding, attacking, and destroying cancer cells.
In 2018, CAR-T cell therapy earned its discoverers, James P. Allison and Tasuku Honjo, the Nobel Prize in Medicine. But in 2010, it was still an experimental procedure. The first adult treatments were taking place in Pennsylvania that year on patients suffering from end-stage leukemia – a blood disorder in which billions of cancer cells spread throughout the body using the circulatory system. In two of the three patients, the therapy made all the tumor cells disappear, never to return.
However, CAR-T cell therapy had never been tested in children. In February 2012, Emily Whitehead was the first pediatric patient to undergo the procedure. The side effects were severe, with very high fever, low blood pressure and pulmonary congestion. But in a matter of hours Emily's condition improved, astounding the entire medical team. Not only did Emily recover from the cytokine storm (the body's excessive immune response) that nearly killed her, but the girl’s custom-made T-cells did exactly what they were supposed to do: they eliminated the cancer. The young woman, now 17 years old, has already completed a decade of remission from leukemia.
In 2017, a committee of the Food and Drug Administration (FDA) unanimously approved the use of CAR-T therapy to fight cancer. At the time, Emily's father gave a statement to the FDA panel. “This treatment will save thousands of children’s lives around the world. I hope that someday all of you on this advisory committee can tell your families for generations that you were part of the process that ended the use of toxic treatments like chemotherapy and radiation as standard treatment and turned blood cancer into a treatable disease that even after relapse, most people survive,” he said.
Since then, more than 10,000 patients worldwide have undergone the procedure, mostly in the United States, but also in Europe, Japan and China. In October 2019, Vamberto Luis de Castro, then 62 years old, terminally ill with B-cell non-Hodgkin lymphoma (another type of blood cancer), was the first to receive treatment in Brazil and recover from the disease.
This text is a collaboration of the scientific journalist Peter Moon for the Butantan portal