A new treatment for a type of childhood cancer is the first FDA-approved use of gene therapy, working as a “living drug” that can use the body’s own immune system to kill cancer cells. Researchers hope the treatment can provides an alternative for patients who have exhausted all other options.
The therapy is called CAR T-cell therapy (CAR means Chimeric Antigen Receptors, and T-cells are cells in our bodies that fight infections). It made headlines in 2012 when the then-experimental therapy was used on 7-year-old Pennsylvanian Emily Whitehead.
Whitehead had been fighting a form of childhood leukemia called Acute Lymphoblastic Leukemia (ALL) for two years, but nothing was working. She became the first patient to receive CAR T-cell therapy, which uses a disabled form of the HIV virus to train killer T-cells to attack the leukemia cells.
A Scary Start
Dr. Stephen Hunger, head of oncology and director of research at Children’s Hospital of Philadelphia where the treatment was developed, was invited to Akron recently to talk to doctors about the breakthrough.
Hunger says the therapy, at first, came close to killing Emily and sent doctors in the ICU into high alert. The team worked around the clock, he says, "to measure everything they could think of measuring.”
They quickly identified a drug that would stop the potentially fatal side effect known as cytokine release syndrome.
“And as soon as she got the drug, she got better," Hunger says.
Hunger says it was a scary start to a therapy that otherwise has worked remarkably well for Whitehead, who five years later remains cancer free.
“If you had told me five and a half years ago, when this first girl was treated, how good it could be, I would have said that you were nuts," Hunger says. "I don’t think anybody involved had any realistic assessment that it could be this effective.”
The drug company Novartis purchased the technology from the Children’s Hospital of Philadelphia and sells it under the name Kymriah.
Considering The Cost
Hunger says the therapy begins when a hospital isolates the T-cells from the patient’s blood. Then, the cells are shipped to the production facility "to be manipulated and manufactured, and when they’re done they’re sent back to the treating facility to infuse the patient.”
It’s not cheap. Without insurance, each treatment runs around $475,000.
But with the cost of a bone marrow transplant running in some cases up to a $1 million, Hunger says the new gene-therapy treatment provides another option.
“Part of the question going forward is, when should you apply this in the course of a patient’s disease, the chance to improve outcome, and what is the most cost-effective approach?” Hunger says.
Dr. Jeffrey Hord, head of the cancer and blood disorders unit at Akron Children’s Hospital, says it will take time before the therapy comes to Akron.
“We don’t know yet what the requirements will be of institutions to use the drug,” Hord says. “I’m sure it will be a limited number of institutions initially.”
He says the drug maker still needs to determine which hospitals can handle the treatment.
“One of the things no doubt that will be considered is, can you handle the complications of those infusions?” Hord says.
Gene Therapy Comes Of Age
Akron Children’s sees about 25 cases of the type of childhood leukemia for which the therapy was designed. According to Hord, around five of them might be candidates for the therapy when standard treatments don’t work.
For now, he says, he’ll still send those patients to places like Children’s Hospital of Philadelphia that offer CAR T-cell therapy.
Just months after the childhood leukemia treatment got the green light, the same technology has now been approved to treat lymphoma in adults. It’s one of 75 new uses of the killer CAR T-cells pending approval, according to the FDA, with hundreds of other gene therapy procedures waiting in the wings.
“Still, not every patient will be cured,” Hunger says.
But he says the decades of basic research in labs around the world are beginning to pay off for families that have run out of options.