US clears first 'living drug' for childhood leukaemia

US officials have approved the first treatment that genetically engineers patients' own blood cells to seek and destroy a childhood leukaemia.

The CAR-T cell treatment developed by Novartis and the University of Pennsylvania is the first type of gene therapy to hit the US market - and one in a powerful but expensive wave of custom-made "living drugs" being tested against blood cancers and some other tumours.