Technique involves leukaemia patients being treated with their own T cells – a type of white blood cell – that have been genetically modified to attack and destroy tumours within their bodies
London
Scientists claim t
o have developed ” serial killer” cells that can wipe out leukaemia within three weeks, a breakthrough they say could lead to new and effective treatments for the fatal blood cancer.
Researchers at the University of Pennsylvanias Abramson Cancer Centre in the US engineered a technique that involved leukaemia patients being treated with their own T cells – a type of white blood cell – that have been genetically modified to attack and destroy tumours within their bodies. The treatment, according to the researchers, was so powerful that tumours were ” blown away” in under a month with few side effects, the Daily Mail reported.
After removing the patients T cells, the researchers reprogrammed them to attack tumours by binding to a protein expressed by cancerous cells.
In most forms of cancer these crucial cells are unable to distinguish tumour cells from healthy tissue, which allows the cancer to spread unchecked. But they managed to reprogramme them to attack tumour cells by inserting a ” secret ingredient” – a protein called a chimeric antigen receptor ( CAR).
When this protein is on the surface of the T cells, it will bind with another protein, called CD19, which is found in leukaemia tumour cells.
By doing this it not only kills the cancer cells, but causes other T cells to rapidly multiply so they can attack the tumour too. Professor Carl June, senior author of the study, said: ” The infused T cells are serial killers. On average each fused T cell led to the killing of thousands of tumour cells – and overall, destroyed at least two pounds []] one kilo] of tumour in each patient. ” We saw at least a 1000- fold increase in the number of modified T cells, which is unprecedented, and it happened in each of the patients. Drugs donalt39t do that. ” Within three weeks the tumours had been blown away, in a way that was much more violent than we ever expected.” The study, published in the Journal of Medicine and Science Translational Medicine, showed that side effects of this process were not as bad as chemotherapy because the CAR only targeted tumour cells and B cells rather than all normal tissue. The treatment was trialled on three patients suffering from chronic lymphocytic leukaemia, which affects the blood and bone marrow and is the most common form of leukaemia. It can be managed with chemotherapy but only be cured by a bone marrow transplant, which carries a one in five risk of dying while only offering a 50/ 50 chance of success.
Gene transfer therapy using T cells has been a holy grail of treatment for various cancers over the past 25 years but has proved very difficult to achieve in human trials.
