‘Ghost’ army of blood cells attack cancer

Doctors at a Paris hospital are creating ‘ghost’ armies of patients’ blood cells that track down and kill certain blood cancers such as acute lymphoblastic leukaemia – and seem particularly effective in children.

So far, only around three dozen patients have been treated by the revolutionary method that was described by Dr Sophie Bernard, onco-haematologist at Paris Saint-Louis Hospital, as using “the immune system to create a made-to-measure drug”.

More could soon benefit as two Paris hospitals, Saint-Louis and Robert Debré, have been declared the first European specialist treatment centres and the ANSM medical agency has given two laboratories temporary approval to manufacture the cells.

The treatment involves taking and freezing some of a patient’s T-cells, a type of white blood cell, then genetically modifying them to recognise specific receptors on cancer cells before infusing them back into the patient. These CAR T-cells then move through the body to attack the cancer and ‘teach’ other T-cells to do the same.

Developed in the US, the American Society of Clinical Oncology hailed it as the ‘discovery of the year’.

Professor André Baruchel, of Robert Debré, told journalists that about 400 children were affected by acute lymphoblastic leukaemia each year and while most responded well to conventional treatments the new CAR T-cell therapy gave a “brighter horizon”.

Dr Bernard said the new therapy offered an “exponential dynamic” in growth of treatment, particularly for the sixth most common adult cancer in France, refractory lymphoma, and had an 80% remission rate for childhood leukaemia relapses.

Initial targets for the therapy – which is still essentially in an advanced trial stage – has been aimed at the particularly aggressive blood cancers acute lymphoblastic leukaemia and large B-cell lymphoma.

While surgery, chemotherapy, and radiation therapy have been the core weapons against cancer for decades, the CAR T-cells are an example of a new form of immunotherapy which turns the patient’s immune system against tumours.

French company Cellectis has also applied for approval in the US for a T-cell treatment that would use gene-edited T-cells from healthy donors, rather than those of the host.