WASHINGTON - At age seven, Emily Whitehead is the only child to have beaten back leukaemia, thanks to a new treatment that turned her own immune cells into targeted cancer killers.
She has been in remission for 11 months and is the first paediatric patient in a United States trial that is showing signs of success after decades of research.
The trial now includes three other children and dozens of adults.
The case studies that describe Emily's journey so far, and that of another 10-year-old girl who did not survive after trying the same adoptive T cell therapy, were detailed on Monday in the New England Journal of Medicine.
Both girls suffered from a high-risk type of acute lymphoblastic leukaemia that resists conventional treatments.
The T cell therapy takes a patient's own white blood cells, called T cells, and genetically alters them to allow them to recognise and kill cancer cells, said Dr Michael Kalos, part of the University of Pennsylvania team working on the project.
Emily's mother said her daughter sometimes grapples with her newfound celebrity, which ballooned after the trial's preliminary results were first announced late last year.
"When we go to places where there are a lot of people, sometimes they want pictures with her, or sometimes just to touch her, so I think it gets a little overwhelming," said Mrs Kari Whitehead.