In a major breakthrough in the search for a cure for cancer, the first human trials are to begin using a technique that has already been shown to destroy the disease in mice. The trials are the culmination of years of research prompted by the discovery of a cancer-proof mouse by researchers almost a decade ago.
Tests on humans have been approved by the US Food and Drug Administration and were announced at a medical conference in Los Angeles yesterday.
More than 20 cancer patients will be given white blood cells with cancer-killing properties in an attempt to boost their immune system's fight against the deadly illness.
The work stems from experiments into the metabolism of a humble laboratory mouse whose immunity to cancer defied the repeated attempts of scientists to kill it with high-level doses of cancer cells. White blood cells taken from the animal and its offspring were subsequently used to cure other mice of advanced cancers. The white blood cells destroyed the cancer cells but left normal cells alone.
This discovery encouraged scientists to study how people might be helped to fight off cancer by being given a boost of white blood cells called granulocytes. Laboratory tests have since shown how human granulocytes can destroy cervical, prostate and breast cancer cells, provided sufficient numbers of cancer-killing granulocytes from healthy donors are used.
Scientists are now confident that the treatment will prove just as successful in humans as it has been in mice. The human trials are being led by Dr Zheng Cui, from Wake Forest University in Winston-Salem, North Carolina, who said: "In mice, we've been able to eradicate even highly aggressive forms of malignancy with extremely large tumours. Hopefully, we will see the same results in humans. Our laboratory studies indicate that this cancer-fighting ability is even stronger in healthy humans."
Hundreds of donors will be recruited for the new treatment – which is called leukocyte infusion therapy – and a process similar to platelet donation will be used to collect the granulocytes. Twenty-two cancer patients in the US will receive the cells through transfusions, and their progress will be reviewed after three months.
The news has been welcomed by cancer charities. Dr Joanna Owens, senior science information officer at the charity Cancer Research UK, said: "This is an exciting approach to treating cancer and the results seen in human cell lines and mice are certainly impressive. Our immune system is an immensely powerful weapon in helping the body to fight disease, and our scientists are also investigating ways to harness it to treat cancer. It's great to see the results of a decade of research offer hope of a potential new treatment, and we look forward to following the progress of the planned clinical trials."