Aaron Walker and his wife, Christal, turned to Children's after reading about Emily Whitehead of Philipsburg, Pa., the first child to receive the hospital's genetically engineered therapy, made using each patient's disease-fighting "T cells." Emily remains in remission, a year after treatment.
Avrey and her parents spent about 50 days in Philadelphia while her T cells were modified, multiplied, and, a month ago, returned to her bloodstream.
"I have heard of miracles like most of us have; however I have never witnessed one in person - until now," Walker said. "We are so thankful!"
The immunotherapy researchers, including Stephan Grupp at Children's and Carl H. June at the University of Pennsylvania, recoil from words like miracle. And they have published results from only the first two children.
Still, the T-cell therapy is showing startling effectiveness, judging from both scientific and parental accounts: Of the first seven children, five had a complete response - no evidence of cancer - although one of them later relapsed. One child did not respond, and one child's outcome has not been made public by parents or doctors.
The therapy involves transferring genes into T cells - the soldiers of the immune system - to make them recognize and attack B cells, the blood component that turns malignant in certain leukemias and lymphomas. There is also evidence that some of the designer T cells develop immune "memory," so they could reactivate and strike if cancer returns.
Recently, this immunotherapy technology has been successfully used in small numbers of patients in studies at Sloan-Kettering Memerial Cancer Center in New York and the National Cancer Institute in Bethesda, Md.
The toxicity of this new approach is not yet clear, and seems to vary. At one extreme, Emily Whitehead nearly died when the T cells threw her immune system into overdrive. Avrey's reaction, in contrast, was unusually mild.
"We were all waiting for the big storm," her father said. "She just felt a little groggy and had a low-grade fever" for about a day.
The durability of the therapeutic effect is also unclear. However, an adult leukemia patient treated at Penn remains cancer-free two and a half years after treatment.
Children like Avrey have never known such a lengthy respite from disease, disability, and dread. Now, her father said, she wants to go back to fourth grade, play softball, hang out with her big sister, Madison.
"We'll try to get back to a normal life," he said, "something we haven't had for 10 years."
Contact Marie McCullough at 215-854-2720 or firstname.lastname@example.org.