Cancer treatments give new hope

Press, 19 December 1988, Page 10

Cancer treatments give new hope

NZPA-AAP London A new form of cancer treatment known as a “magic bullet,” developed by a British hospital research, team, will soon be used in limited trials on human volunteers.

The treatment got its name because of its potential for selectively delivering higher doses of cell-killing drugs to tumours.

The therapy differed from conventional anticancer drugs, which had to be given in limited amounts because they killed normal cells as well as cancerous ones.

The treatment had successfully eradicated human cancer tumours resistant to conventional therapy in 80 to 100 per cent of mice in studies carried out by the Cancer Research Campaign laboratories in London’s Charing Cross Hospital. Professor Kenneth Bagshawe, who headed the research team, said trials on 20 patients with bowel cancer would start

next year. The treatment, called “Adept” (Anti-body Directed Enzyme Prodrug Therapy), worked by attaching an enzyme to a cancer-seeking anti-body in a form which could be injected into the patient.

A few hours later, the patient would be injected with a harmless “prodrug”, designed to release an active cell-killing drug — but only when it encountered the unique enzyme delivered to the cancer tumours.

Professor Bagshawe said the production of Adept at present was extremely expensive and trials of the first 20 volunteers would cost around £250,000 ($NZ711,845) The development was one of two announced here last week in the medical magazine, “Lancet.”

In a separate development, doctors at the Medical Research Council’s Laboratory of Molecular Biology in Cambridge announced two patients

were in remission after treatment with monoclonal antibodies. Monoclonal antibodies were biologically engineered and could be aimed against cancer cells in a human body — which made them similar to a “magic bullet” form of treatment — but until now, their use had been severely limited because the body recognised them as foreign.

Dr Mike Clarke said the two remission cases did not mean the research team had found a cure, but in both cases all the cancer cells had been destroyed. He said the long-term benefits could be assessed only in a much larger trial where the new treatment would be combined with more conventional chemotherapy and radiotherapy.

Scientists at the Cambridge Medical Research Council laboratory won the Nobel Prize for their development of monoclonal antibodies in 1975.