Acute myeloid leukemia (AML) is a type of cancer of the blood and bone marrow that affects immature blood cell growth.
The research showed that AML is in remission among patients who received this experimental T-cell therapy after a bone marrow transplant.
Giving these cells when the disease is in remission after transplant "might actually be helping patients who have a high risk of relapsing to not relapse down the line", said Aude Chapuis, physician at Fred Hutchinson Cancer Research Center in the US.
Conversely, in transplant-only patients, the transplants produced remissions, but more than a quarter of them relapsed within just 10 months, the researchers said.
For the trial, the team focussed on 12 AML patients who were undergoing bone marrow transplant and had certain genetic or disease characteristics that decreased the chance of long-term transplant success.
Certain T-cells from each patient's transplant donor were genetically engineered to produce receptors that allowed the T-cells to recognise, very specifically, WT1 -- a target molecule 10 to 1,000 times more common in leukemia cells.
Then the patients' leukemic bone marrow and blood cells were destroyed and replaced with healthy cells from their donors.
A month later, when the team examined these 12 patients' marrow, they found no trace of the cancers.
Rapidly thereafter, once the transplanted cells fully engrafted, each patient then received up to 10 billion of the genetically engineered donor cells, infused into their arm through an IV.
The results were presented at the 2016 annual meeting of the American Society of Hematology in San Diego, California.