Gene editing fights leukaemia

Doctors at Great Ormond Street children’s hospital in London are thrilled to announce that two baby girls with cancer, who were both treated with gene-edited immune cells, are doing well more than a year later, according to a report published in the journal Science Translational Medicine.

Back in November 2015, the team announced that a baby girl with leukaemia had been treated with an experimental therapy made from immune cells modified using new gene editing technique. Another baby girl was also treated in December that year, and both received the treatment as a last-ditch attempt when all other options had failed.

Known as CAR-T cells, the therapy involves modifying immune cells, known as T-cells, so that they spot cancer cells and destroy them. Many trials are underway around the world using modified versions of a patient’s own T cells, in order to avoid provoking an immune response against the therapy, although this level of personalisation makes the treatment very expensive and challenging to do. By using gene editing to knock out a gene in T cells that provokes the immune system, bulk-produced modified CAR-T cells can be given to any patient.

It’s not perfect, and just under 1 per cent of the modified T cells still stimulated an immune response, which can be very serious. But once it had settled down in the two treated babies, the modified T cells got to work killing their cancer cells. Further trials are now underway in other parts of the world, making this a hugely exciting area to watch for potential future cancer cures.