Eden Oyelola, whose battle with brain cancer was chronicled in a Washington Post story in September, died last week, said her mother, Sara Amare.
Eden, who was 6 and lived with her family in Upper Marlboro, Maryland, was diagnosed with a malignant brain tumour in 2014.
When traditional therapies failed to keep the tumour from recurring, she was enrolled earlier this year in a first-of-its kind clinical trial at Children's National Medical Centre. The early-phase trial was testing a new immunotherapy drug against aggressive brain tumours.
The drug, called Keytruda, has shown impressive results in treating advanced melanoma in adults, as well as bladder and lung cancer. It was used, along with surgery and radiation, to successfully treat former President Jimmy Carter, who had melanoma. Paediatric oncologists are eager to try the drug, as well as other new immunotherapy treatments, in children who haven't recovered after receiving standard treatment.
Eden got her first dose of Keytruda in June, but her tumour was growing too quickly for the drug to have the desired effect, her doctors said. As a result, she wasn't able to continue on the trial.
Eugene Hwang, a paediatric neuro-oncologist who led the trial, said that Eden's death is a "stark reminder" of the terrible plight facing children with brain cancer and their families.
Brain cancer has in recent years replaced leukaemia as the leading type of cancer that kills children. Although medicine has made great strides against leukaemia, it has been largely stymied by aggressive brain tumours.
"Eden's family would have given anything, gone anywhere, would have traded places with her in an instant if that meant she would beat her cancer," Hwang said.
"We were unable to cure her, but will remember her as an inspiration to drive all of us, every day, to find better treatments for children with brain tumours."