Researchers used 5 billion copies of a single immune cell from a man to wipe out signs of his advanced melanoma for more than two years, according to a report in the New England Journal of Medicine. Copies of an infection-fighting CD4 T cell were grown in a laboratory, and then used to attack the 52-year-old patient’s tumor, the report said. Previously, scientists had difficulty isolating and copying immune system cells, the researchers wrote in the report. The man had recurrent melanoma that failed to respond to therapy or surgery when he enrolled in a clinical trial at the Fred Hutchinson Cancer Research Center in Seattle. The disease had spread to his lungs and a lymph node before he received the two-hour infusion of the lab-grown immune system cells. Sixty days later, all signs of the disease were gone. He remained in remission for the following two years, researchers said. “We were surprised by the anti-tumor effect of these CD4 T cells and its duration of response,” said Cassian Yee, the senior author of the paper and an associate member of the clinical research division, in a statement. “For this patient we were successful, but we would […]