An experimental lung cancer drug has extended patients' life expectancy by more than 50% in preliminary trials.
Lung cancer prognosis can be poor
Patients given the drug AS1404 on top of standard chemotherapy lived an average of 14 months compared with 8.8 months if given chemotherapy alone.
The phase two study, by UK biotech company Antisoma, looked at 70 patients with non-small cell lung cancer, the most common form of the disease.
It kills more than 26,000 people in Britain each year.
The drug belongs to a new class of compounds called vascular disrupting agents, which work by cutting off the blood supply to tumours.
Solid tumours rely on a network of blood vessels to survive and grow.
AS1404 is able to distinguish between blood vessels feeding the tumour and those serving healthy organs.
The tumour vessels are more permeable and less well organised than those of healthy tissue.
Dr Mark McKeage, from the University of Auckland in New Zealand, who co-led the trial, said: "It is great to see this large survival benefit with AS1404 in lung cancer patients.
"This makes me feel very optimistic as we proceed into phase three testing."
Glyn Edwards, chief executive officer of Antisoma, said: "Survival is the gold standard by which cancer drugs are judged, and this news is therefore very exciting."
AS1404 was developed by scientists in New Zealand but the pharmaceutical company it was initially licensed to did not have the resources to develop it further.
The charity Cancer Research UK stepped in to take the drug into early-stage clinical trials.
Phase two trials are carried out to see whether the drug or treatment is effective for treating cancer.
A phase three trial directly compares the new treatment with standard treatments to see if the new treatment is better.