DOCTORS have successfully rid a patient of advanced skin cancer by treating him with clones of his own immune cells.
In just two months, scans showed that the 52-year-old man’s tumours, which had spread to his lungs, were gone.
The astonishing outcome is the first solid evidence that the experimental T-cell treatment works.
But the US scientists are quick to point out that the breakthrough involved just one patient. Further trials will be needed to prove that the results were no fluke.
Advanced malignant melanoma, the most dangerous form of skin cancer, is notoriously difficult to treat once it starts to spread.
The US team, led by Dr Cassian Yee, from the Fred Hutchinson Cancer Research Centre in Seattle, pioneered a new therapy based on infection-fighting “helper” CD4 T-cells from the patient’s own immune system. Helper T-cells are specialised white blood cells that “target” foreign invaders or cancerous cells, and marshal other elements of the immune system against them.
The new technique involved extracting helper T-cells from the patient and cloning those specifically targeting melanoma. They were then stimulated to divide and multiply in the laboratory, boosting their numbers 3,000 to 5,000-fold.
Around five billion of the lab-grown cells were then infused back into the patient, unaccompanied by any additional therapies.
After two months the patient was found to be tumour-free, and there was still no sign of cancer when he was last checked two years later. Before treatment, the man had Stage 4 advanced melanoma which had spread to a groin lymph node and one of his lungs.
Dr Yee said: “We were surprised by the anti-tumour effect of these CD4 T-cells and its duration of response. For this patient we were successful, but we would need to confirm the effectiveness of therapy in a larger study.”
The patient had a specific type of immune system, and tumour cells producing a specific “antigen” – the protein equivalent of a “flag” that is recognised by the helper T-cells.
Dr Yee predicted that if the approach proved successful in other patients, it could be used for the 25% of late-stage melanoma sufferers sharing the same profile as the trial patient.
The findings were published yesterday in the New England Journal of Medicine.
The cloned T-cells persisted for at least 80 days in the patient’s body, the researchers said.
Even though only 50% to 75% of the tumour cells bore the specific antigen “flag” recognised by the T-cells, all the cancer regressed after the treatment.
The treatment may have caused the patient’s immune system to broaden out and recognise other tumour antigens, said the scientists.
Follow-up tests revealed T-cell responses to two additional tumour antigens.
The researchers wrote: “During regression of the tumour, this clone appears to have induced the patient’s own T-cells to respond to other antigens of his tumour.”
Ed Yong, health information manager at the charity Cancer Research UK, said: “It’s very exciting to see a cancer patient being successfully treated using immune cells cloned from his own body. While it’s always good news when anyone with cancer gets the all-clear, this treatment will need to be tested in large clinical trials to work out how widely it could be used.”
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