Andreas (Garching)
Drug Makes Cancer Cells Sensitive to Treatment
Reuters Health
By Patricia Reaney
Monday, October 28, 2002
COVENTRY, England (Reuters) - A new drug that destroys cancer cells´ protective shield could improve the effectiveness of radiotherapy and chemotherapy treatments.
Professor Hilary Calvert of the University of Newcastle in northern England told a medical conference Monday that cancer treatments work by damaging the DNA in the cells.
All cells sustain DNA damage daily from oxygen and chemicals circulating in the body and have a type of repair kit. But in cancerous cells, the kit protects them and also reduces the effectiveness of anti-cancer therapies.
The new drug, called TBT699, blocks the action of enzymes, called PARPS, that help cancer cells repair themselves and make them more sensitive to radiotherapy and anti-cancer drugs.
"We know that cancer cells are sometimes resistant to these drugs or radiotherapy because they can just repair the damaged DNA and carry on," Calvert told a news conference.
"What this drug is doing is actually preventing the cancer cells from effecting that repair and therefore it should make the radiotherapy and drugs work better," he added.
Laboratory tests and animal studies have shown the drug can sensitize the cancerous cells to the treatments without producing damaging side effects.
Calvert and his team are hoping to begin clinical trials on patients suffering from melanoma, the deadliest type of skin cancer. They plan to combine the drug with a chemotherapy treatment in a trial in Britain in the next few months.
"We have been trying to find something to make tumors more sensitive to radiotherapy. And we hope the PARP inhibitor will prove an effective radiosensitizer, which would be a huge benefit to cancer patients," Calvert explained.
The drug, which would be injected and would work for about 6 hours, could work on various types of cancer including brain, skin, colon, ovarian and small cell lung cancer.
Calvert told the first annual meeting of the medical charity Cancer Research UK that the drug works on normal as well as cancerous cells but the effect the combination of treatments has on the cancer cells is greater.
"We are trying a different approach and we know from the experiments we have done that we are pretty certain there will be very little toxicity (side effects) from the PARP inhibitor itself," Calvert added.
Up to 300 of Britain´s top cancer researchers are attending the 3-day meeting in Coventry, central England, which will set the agenda for cancer research in Britain.