- The first trial of a cancer drug designed to starve tumours
into submission has shown that it may work.
- Seventeen cancer patients at the Mount Vernon and Hammersmith
Hospitals in West London were given the drug, Combretastatin, originally
isolated from an African plant, the bush willow. The treatment curtailed
blood flow to the tumours, suggesting that in combination with radiation
or another drug, it could form an effective therapy.
- Dr Gordon Rustin, of Mount Vernon Hopsital, said yesterday:
"This study is very exciting because it is the first time in cancer
research that a drug has been shown to reduce blood flow to patients' tumours.
This proves that the theory of starving someone's tumour of oxygen can
work in practice and it has opened the door for new cancer treatments in
- The results are also a timely boost for a type of therapy
that has proved controversial in America. In May last year, Dr Judah Folkman
of Harvard Medical School in Boston reported that he had shrunk cancers
in mice to microscopic sizes using two blood-starving agents, endostatin
and angiostatin. Other laboratories have found reproducing the effect difficult
or impossible. Despite this, patients are being recruited for a trial of
endostatin in America.
- The British trials, organised by the Cancer Research
Campaign and carried out in conjunction with the biotech company Oxigene,
based in Stockholm, did not seek to shrink the tumours but simply to see
if blood flow was reduced. The results, said Björn Nordenvall, president
of Oxigene, demonstrated "proof of principle".
- Patients were given a ten-minute infusion of the drug
into a blood vessel once a week. The main side-effect was temporary pain
at the site of the tumour within two hours in some patients, probably caused
by the interruption of blood flow.
- Dr Rustin told the Angiogenesis '99 conference in London
yesterday that such agents given alone would never lead to cures, because
there would always be cancer cells on the outside of the tumours that could
get their nourishment from surrounding tissue. But adding tumour-killing
drugs or radiation sources to Combretastatin was producing good results
in animal tests. In some experiments in mice, colon cancers appeared to
have been eliminated.