Genetically engineered immune cells can drive an aggressive type of leukaemia into retreat, a small clinical trial suggests. The results of the trial — done in five patients with acute lymphoblastic leukaemia — are published in Science Translational Medicine1 and represent the latest success for a 'fringe' therapy in which a type of immune cell called T cells are extracted from a patient, genetically modified, and then reinfused back. In this case, the T cells were engineered to express a receptor for a protein on other immune cells, known as B cells, found in both healthy and cancerous tissue.
When reintroduced into the patients, the tricked T cells quickly homed in on their targets. “All of our patients very rapidly cleared the tumour,” says Michel Sadelain, a researcher at the Memorial Sloan-Kettering Cancer Center in New York and an author of the study. The treatment “worked much faster than we thought”. The technique has already shown promise against chronic leukaemia, but there were doubts about whether it could take on the faster-growing acute lymphoblastic leukaemia, a tenacious disease that kills more than 60% of those afflicted. Carl June, an immunologist at the University of Pennsylvania in Philadelphia and a pioneer in engineering T cells to fight cancer, says that he is surprised that the method worked so well against such a swift-growing cancer. The next step, he says, is to move the technique out of the ‘boutique’ academic cancer centres that developed it and into multicentre clinical trials. “What needs to be done is to convince oncologists and cancer biologists that this new kind of immunotherapy can work,” he says.