A large-scale trial to test a vaccine against the most common form of lung cancer has been launched.
Lung cancer can be difficult to treat
More than 1,300 patients worldwide will help test Stimuvax, which in preliminary trials substantially increased survival time for many.
There were more than 37,000 people diagnosed with lung cancer in the UK in 2003, and death rates remain high.
The vaccine works by stimulating the body's own immune system to attack cancer cells.
It is aimed at the non-small cell type of lung cancer, which accounts for four-fifths of cases in the UK.
Currently, patients receive combinations of surgery, chemotherapy and radiotherapy.
Half of the people taking part in the worldwide trial will get this treatment, plus the vaccine, while the other half will get just the treatment, and a dummy vaccine called a placebo, so that scientists can compare survival in the two groups.
The vaccine was developed following research funded by Cancer Research UK, and the technology was licensed to be developed by Canadian biotech firm Biomira.
Dr Keith Blundy, chief operating officer of Cancer Research Technology, the charity's commercial arm, said: "Targeted vaccines are an exciting approach that could potentially offer new treatment options for major types of cancer."
Other researchers are looking at the potential for the same vaccine to tackle other types of cancer.
It works by priming the body's immune system to attack a chemical called MUC-1, which is found only on the surface of cancer cells.
Once this has happened, the body should be able to destroy cancer cells while leaving healthy cells unaffected.
Survival time 'increased'
Smaller-scale trials, involving 171 patients who had responded to conventional treatment, suggested that the vaccine might be helping some patients in their fight against the cancer.
Again, half the patients received normal treatment plus the vaccine, half got treatment and a dummy vaccine.
The patients were then monitored as they returned for check-ups over the next few years.
In the placebo group, half the patients survived 13 months or longer. In the vaccine group, half survived 30 months or longer.
If these large-scale trials yield similarly positive results, the vaccine could eventually be made more widely available to lung cancer patients.
Harpal Kumar, the chief operating officer of Cancer Research UK, said: "The 'translation' of basic research into patient benefit is the major focus of our work and we hope that new ventures will lead to many more such drugs entering trials in the future."