Melanoma vaccine enters clinical trials
Treatment could teach the immune system to fight skin cancer.
A vaccine that could help patients recover from a common form of skin cancer is to undergo large-scale trials in Australia and Britain.
The vaccine is designed to target melanoma, which is a deadly form of cancer that accounts for roughly 2% of new cancer cases in Britain each year. Melanoma commonly develops as a result of prolonged sun exposure, and if left untreated can spread to other parts of the body.
Although melanoma is not caused by an infection, the body's immune system can still mount a defence against the cancerous cells, according to Vincenzo Cerundolo, an immunologist at the Weatherall Institute for Molecular Medicine in Oxford, UK.
Cerundolo says that melanoma cells produce a characteristic protein, known as NY-ESO-1, which the immune system can learn to recognize. Once the system spots the proteins, it will attack the tumour that is producing them. "The problem is that by the time the immune system learns to recognize the tumour it is usually too late," says Cerundolo.
The new vaccine is essentially a synthetic form of this protein that teaches the immune system to look for tumours earlier on. Researchers inject the protein along with a drug that boosts its uptake by immune cells. A small-scale study conducted in Australia by the Ludwig Institute for Cancer Research has already produced promising results. It showed that cancer patients who were given the vaccine after their tumours had been surgically removed were almost three times less likely to see their cancer recur1.
Now the Ludwig Institute is planning a much larger, US$600,000 clinical trial of the vaccine. The study, involving roughly 100 patients in Australia and Britain, will be completed by late 2005, Cerundolo says.
Lawrence Young, head of cancer studies at the University of Birmingham, UK, says the vaccine approach could be especially useful in treating melanoma, which responds poorly to other techniques such as chemotherapy.
But if the trial is successful, the approach may also be tested on certain breast and prostate cancers that produce similar proteins.
- Davis I. et al. Proc. Natl Acad. Sci., 101. 10697 - 10702, doi/10.1073/pnas.0403572101 (2004).