Immune system '˜can be trained to attack cancer'
A potentially revolutionary therapy that trains the immune system to attack cancer has shown 'extraordinary' results in early trials involving terminally ill patients.
In one study 94% of participants with acute lymphoblastic leukaemia (ALL) saw their symptoms vanish completely.
Patients with other blood cancers saw response rates greater than 80% with more than half experiencing complete remission.
The technique involves removing immune cells called T-cells from patients, tagging them “receptor” molecules that target cancer, and infusing them back in the body.
Scientists screened specially bred genetically engineered mice for the targeting molecules, known as chimeric antigen receptors or Cars.
Once attached to the T-cells, they reduce the chances of the cancer being able to shield itself from the immune system.
Lead scientist Professor Stanley Riddell, from the Fred Hutchinson Cancer Research Center in Seattle, said: “These are in patients that have failed everything. Most in our trial would be projected to have two to five months to live. This is extraordinary. This is unprecedented in medicine to be honest, to get response rates in this range in these very advanced patients.”
Prof Riddell, who was speaking at the American Association for the Advancement of Science annual meeting in Washington DC, described the results as a “potential paradigm shift.”
At the same time he acknowledged much more work had to be done, and it was not clear how long the symptom-free patients would remain in remission.
So far, the technique has only been tried on patients with “liquid” blood cancers, not solid tumours. And seven of the 35 ALL patients had suffered a very serious side affect caused by an over-powerful immune response, which required intensive care. Two died. Meanwhile a study by researchers at the University of Milan raises the prospect of vaccine-like treatments that protect against cancer for life. Scientists identified and tracked rare immune system cells that could be programmed to keep cancer at bay over a period of many years.