Updated on 9 December 2013
The treatment involves filtering patients' blood to remove millions of white blood cells called T-cells, altering them in the lab to contain a gene that targets cancer, and returning them to the patient in infusions over three days.
"What we are giving essentially is a living drug -- permanently altered cells that multiplied in the body into an army to fight the cancer," said David Porter, a University of Pennsylvania scientist who led one study.
Several drug and biotech companies were developing the therapies. The University of Pennsylvania has patented its method and licensed it to Switzerland-based Novartis. The company is building a research centre on the university campus in Philadelphia and plans a clinical trial next year that could lead to federal approval as soon as 2016.