`Copycat' cancer therapy goes on trial

LIZ HUNT

Health Editor

Clinical trials have begun on a new approach to treating cancer, using "copycat" molecular blockers to stop tumour cells multiplying, scientists said yesterday.

Patients suffering from different cancers will initially take part in the trials at the Western General Hospital, Edinburgh, to test the potential of the new therapy.

However, one form of lung cancer, small cell lung cancer or oat cell carcinoma which is responsible for 25 per cent of all new cases in the UK, is the real focus of the trial. Initially responsive to drugs, the cancer returns in all but 5 to 10 per cent of patients and is usually resistant to drugs the second time.

Professor John Smyth, director of the Imperial Cancer Research Fund's Clinical Oncology Unit at the hospital, said yesterday: "We desperately need entirely new approaches if we are to make major differences for patients with a number of types of cancer - particularly the common types."

The trial is the culmination of a 15-year research project by scientists at the ICRF who have shown that molecules known as neuropeptides are potent growth factors. They dock on to the receptor sites on the surface of some cancer cells and stimulate cell growth, sending signals which over- ride healthy cell controls which limit multiplication. Some cancer cells even make their own growth factors to accelerate the process further.

Dr Enrique Rozengurt, from the ICRF's London laboratory, said: "What we have done is discovered ways of blocking these growth factors using antagonist lookalikes which themselves dock onto the receptors, getting in the way of the growth factors. We have identified a group of antagonists which can block every type of growth factor with a particular type of signal."

The scientists are hoping that chemotherapy followed by growth factor blockers will be a more effective treatment for small cell lung cancer. By the end of the decade, Professor Smyth said, scientists will know if they have made a breakthrough in treatment for this type of cancer.

There are 42,300 new cases of lung cancer each year, of which 10,000 are of small cell lung cancer. The Phase 1 trials in Edinburgh will determine the safety and efficacy of the new therapy, and the appropriate dose.